gosnowflake

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 Go to latest Published: Jul 20, 2022 License: Apache-2.0 Imports: 68 Imported by: 0

README

Go Snowflake Driver

This topic provides instructions for installing, running, and modifying the Go Snowflake Driver. The driver supports Go's database/sql package.

Prerequisites

The following software packages are required to use the Go Snowflake Driver.

Go

The latest driver requires the Go language 1.17 or higher. The supported operating systems are Linux, Mac OS, and Windows, but you may run the driver on other platforms if the Go language works correctly on those platforms.

Installation

Get Gosnowflake source code, if not installed.

go get -u github.com/snowflakedb/gosnowflake

Docs

For detailed documentation and basic usage examples, please see the documentation at godoc.org.

Sample Programs

Snowflake provides a set of sample programs to test with. Set the environment variable $GOPATH to the top directory of your workspace, e.g., ~/go and make certain to include $GOPATH/bin in the environment variable $PATH. Run the make command to build all sample programs.

make install

In the following example, the program select1.go is built and installed in $GOPATH/bin and can be run from the command line:

SNOWFLAKE_TEST_ACCOUNT=<your_account> \
SNOWFLAKE_TEST_USER=<your_user> \
SNOWFLAKE_TEST_PASSWORD=<your_password> \
select1
Congrats! You have successfully run SELECT 1 with Snowflake DB!

Development

The developer notes are hosted with the source code on GitHub.

Testing Code

Set the Snowflake connection info in parameters.json:

{
    "testconnection": {
        "SNOWFLAKE_TEST_USER":      "<your_user>",
        "SNOWFLAKE_TEST_PASSWORD":  "<your_password>",
        "SNOWFLAKE_TEST_ACCOUNT":   "<your_account>",
        "SNOWFLAKE_TEST_WAREHOUSE": "<your_warehouse>",
        "SNOWFLAKE_TEST_DATABASE":  "<your_database>",
        "SNOWFLAKE_TEST_SCHEMA":    "<your_schema>",
        "SNOWFLAKE_TEST_ROLE":      "<your_role>"
    }
}

Install jq so that the parameters can get parsed correctly, and run make test in your Go development environment:

make test

Submitting Pull Requests

You may use your preferred editor to edit the driver code. Make certain to run make fmt lint before submitting any pull request to Snowflake. This command formats your source code according to the standard Go style and detects any coding style issues.

Support

For official support, contact Snowflake support at: https://support.snowflake.net/.

Documentation

Overview

Package gosnowflake is a pure Go Snowflake driver for the database/sql package.

Clients can use the database/sql package directly. For example: 

import (
	"database/sql"

	_ "github.com/snowflakedb/gosnowflake"
)

func main() {
	db, err := sql.Open("snowflake", "user:password@my_organization-my_account/mydb")
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()
	...
}

Connection String

Use the Open() function to create a database handle with connection parameters: 

db, err := sql.Open("snowflake", "<connection string>")

The Go Snowflake Driver supports the following connection syntaxes (or data source name (DSN) formats):

  • username[:password]@<account_identifier>/dbname/schemaname[?param1=value&...&paramN=valueN]
  • username[:password]@<account_identifier>/dbname[?param1=value&...&paramN=valueN]
  • username[:password]@hostname:port/dbname/schemaname?account=<account_identifier>[&param1=value&...&paramN=valueN]

where all parameters must be escaped or use Config and DSN to construct a DSN string.

For information about account identifiers, see the Snowflake documentation (https://docs.snowflake.com/en/user-guide/admin-account-identifier.html).

The following example opens a database handle with the Snowflake account named "my_account" under the organization named "my_organization", where the username is "jsmith", password is "mypassword", database is "mydb", schema is "testschema", and warehouse is "mywh": 

db, err := sql.Open("snowflake", "jsmith:mypassword@my_organization-my_account/mydb/testschema?warehouse=mywh")

Connection Parameters

The connection string (DSN) can contain both connection parameters (described below) and session parameters (https://docs.snowflake.com/en/sql-reference/parameters.html).

The following connection parameters are supported:

  • account <string>: Specifies your Snowflake account, where "<string>" is the account identifier assigned to your account by Snowflake. For information about account identifiers, see the Snowflake documentation (https://docs.snowflake.com/en/user-guide/admin-account-identifier.html).

    If you are using a global URL, then append the connection group and ".global" (e.g. "<account_identifier>-<connection_group>.global"). The account identifier and the connection group are separated by a dash ("-"), as shown above.

    This parameter is optional if your account identifier is specified after the "@" character in the connection string.

  • region <string>: DEPRECATED. You may specify a region, such as "eu-central-1", with this parameter. However, since this parameter is deprecated, it is best to specify the region as part of the account parameter. For details, see the description of the account parameter.

  • database: Specifies the database to use by default in the client session (can be changed after login).

  • schema: Specifies the database schema to use by default in the client session (can be changed after login).

  • warehouse: Specifies the virtual warehouse to use by default for queries, loading, etc. in the client session (can be changed after login).

  • role: Specifies the role to use by default for accessing Snowflake objects in the client session (can be changed after login).

  • passcode: Specifies the passcode provided by Duo when using multi-factor authentication (MFA) for login.

  • passcodeInPassword: false by default. Set to true if the MFA passcode is embedded in the login password. Appends the MFA passcode to the end of the password.

  • loginTimeout: Specifies the timeout, in seconds, for login. The default is 60 seconds. The login request gives up after the timeout length if the HTTP response is success.

  • authenticator: Specifies the authenticator to use for authenticating user credentials:

  • To use the internal Snowflake authenticator, specify snowflake (Default).

  • To authenticate through Okta, specify https://<okta_account_name>.okta.com (URL prefix for Okta).

  • To authenticate using your IDP via a browser, specify externalbrowser.

  • To authenticate via OAuth, specify oauth and provide an OAuth Access Token (see the token parameter below).

  • application: Identifies your application to Snowflake Support.

  • insecureMode: false by default. Set to true to bypass the Online Certificate Status Protocol (OCSP) certificate revocation check. IMPORTANT: Change the default value for testing or emergency situations only.

  • token: a token that can be used to authenticate. Should be used in conjunction with the "oauth" authenticator.

  • client_session_keep_alive: Set to true have a heartbeat in the background every hour to keep the connection alive such that the connection session will never expire. Care should be taken in using this option as it opens up the access forever as long as the process is alive.

  • ocspFailOpen: true by default. Set to false to make OCSP check fail closed mode.

  • validateDefaultParameters: true by default. Set to false to disable checks on existence and privileges check for Database, Schema, Warehouse and Role when setting up the connection

All other parameters are interpreted as session parameters (https://docs.snowflake.com/en/sql-reference/parameters.html). For example, the TIMESTAMP_OUTPUT_FORMAT session parameter can be set by adding: 

...&TIMESTAMP_OUTPUT_FORMAT=MM-DD-YYYY...

A complete connection string looks similar to the following: 

	my_user_name:my_password@ac123456/my_database/my_schema?my_warehouse=inventory_warehouse&role=my_user_role&DATE_OUTPUT_FORMAT=YYYY-MM-DD
                                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                                                      connection                     connection           session
                                                                      parameter                      parameter            parameter

Session-level parameters can also be set by using the SQL command "ALTER SESSION" (https://docs.snowflake.com/en/sql-reference/sql/alter-session.html).

Alternatively, use OpenWithConfig() function to create a database handle with the specified Config.

Proxy

The Go Snowflake Driver honors the environment variables HTTP_PROXY, HTTPS_PROXY and NO_PROXY for the forward proxy setting.

NO_PROXY specifies which hostname endings should be allowed to bypass the proxy server, e.g. no_proxy=.amazonaws.com means that Amazon S3 access does not need to go through the proxy.

NO_PROXY does not support wildcards. Each value specified should be one of the following:

  • The end of a hostname (or a complete hostname), for example: ".amazonaws.com" or "xy12345.snowflakecomputing.com".

  • An IP address, for example "192.196.1.15".

If more than one value is specified, values should be separated by commas, for example: 

no_proxy=localhost,.my_company.com,xy12345.snowflakecomputing.com,192.168.1.15,192.168.1.16

Logging

By default, the driver's builtin logger is exposing logrus's FieldLogger and default at INFO level. Users can use SetLogger in driver.go to set a customized logger for gosnowflake package.

In order to enable debug logging for the driver, user could use SetLogLevel("debug") in SFLogger interface as shown in demo code at cmd/logger.go. To redirect the logs SFlogger.SetOutput method could do the work.

Query request ID

A specific query request ID can be set in the context and will be passed through in place of the default randomized request ID. For example: 

requestID := ParseUUID("6ba7b812-9dad-11d1-80b4-00c04fd430c8")
ctxWithID := WithRequestID(ctx, requestID)
rows, err := db.QueryContext(ctxWithID, query)

Canceling Query by CtrlC

From 0.5.0, a signal handling responsibility has moved to the applications. If you want to cancel a query/command by Ctrl+C, add a os.Interrupt trap in context to execute methods that can take the context parameter (e.g. QueryContext, ExecContext). 

// handle interrupt signal
ctx, cancel := context.WithCancel(context.Background())
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt)
defer func() {
	signal.Stop(c)
}()
go func() {
	select {
	case <-c:
		cancel()
	case <-ctx.Done():
	}
}()
... (connection)
// execute a query
rows, err := db.QueryContext(ctx, query)
... (Ctrl+C to cancel the query)

See cmd/selectmany.go for the full example.

Supported Data Types

The Go Snowflake Driver now supports the Arrow data format for data transfers between Snowflake and the Golang client. The Arrow data format avoids extra conversions between binary and textual representations of the data. The Arrow data format can improve performance and reduce memory consumption in clients.

Snowflake continues to support the JSON data format.

The data format is controlled by the session-level parameter GO_QUERY_RESULT_FORMAT. To use JSON format, execute: 

ALTER SESSION SET GO_QUERY_RESULT_FORMAT = 'JSON';

The valid values for the parameter are:

  • ARROW (default)
  • JSON

If the user attempts to set the parameter to an invalid value, an error is returned.

The parameter name and the parameter value are case-insensitive.

This parameter can be set only at the session level.

Usage notes:

  • The Arrow data format reduces rounding errors in floating point numbers. You might see slightly different values for floating point numbers when using Arrow format than when using JSON format. In order to take advantage of the increased precision, you must pass in the context.Context object provided by the WithHigherPrecision function when querying.

  • Traditionally, the rows.Scan() method returned a string when a variable of types interface was passed in. Turning on the flag ENABLE_HIGHER_PRECISION via WithHigherPrecision will return the natural, expected data type as well.

  • For some numeric data types, the driver can retrieve larger values when using the Arrow format than when using the JSON format. For example, using Arrow format allows the full range of SQL NUMERIC(38,0) values to be retrieved, while using JSON format allows only values in the range supported by the Golang int64 data type.

    Users should ensure that Golang variables are declared using the appropriate data type for the full range of values contained in the column. For an example, see below.

When using the Arrow format, the driver supports more Golang data types and more ways to convert SQL values to those Golang data types. The table below lists the supported Snowflake SQL data types and the corresponding Golang data types. The columns are:

  1. The SQL data type.

  2. The default Golang data type that is returned when you use snowflakeRows.Scan() to read data from Arrow data format via an interface{}.

  3. The possible Golang data types that can be returned when you use snowflakeRows.Scan() to read data from Arrow data format directly.

  4. The default Golang data type that is returned when you use snowflakeRows.Scan() to read data from JSON data format via an interface{}. (All returned values are strings.)

  5. The standard Golang data type that is returned when you use snowflakeRows.Scan() to read data from JSON data format directly.

    Go Data Types for Scan() =================================================================================================================== | ARROW | JSON =================================================================================================================== SQL Data Type | Default Go Data Type | Supported Go Data | Default Go Data Type | Supported Go Data | for Scan() interface{} | Types for Scan() | for Scan() interface{} | Types for Scan() =================================================================================================================== BOOLEAN | bool | string | bool ------------------------------------------------------------------------------------------------------------------- VARCHAR | string | string ------------------------------------------------------------------------------------------------------------------- DOUBLE | float32, float64 [1] , [2] | string | float32, float64 ------------------------------------------------------------------------------------------------------------------- INTEGER that | int, int8, int16, int32, int64 | string | int, int8, int16, fits in int64 | [1] , [2] | | int32, int64 ------------------------------------------------------------------------------------------------------------------- INTEGER that doesn't | int, int8, int16, int32, int64, *big.Int | string | error fit in int64 | [1] , [2] , [3] , [4] | ------------------------------------------------------------------------------------------------------------------- NUMBER(P, S) | float32, float64, *big.Float | string | float32, float64 where S > 0 | [1] , [2] , [3] , [5] | ------------------------------------------------------------------------------------------------------------------- DATE | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIME | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_LTZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_NTZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_TZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- BINARY | []byte | string | []byte ------------------------------------------------------------------------------------------------------------------- ARRAY | string | string ------------------------------------------------------------------------------------------------------------------- OBJECT | string | string ------------------------------------------------------------------------------------------------------------------- VARIANT | string | string

    [1] Converting from a higher precision data type to a lower precision data type via the snowflakeRows.Scan() method can lose low bits (lose precision), lose high bits (completely change the value), or result in error.

    [2] Attempting to convert from a higher precision data type to a lower precision data type via interface{} causes an error.

    [3] Higher precision data types like *big.Int and *big.Float can be accessed by querying with a context returned by WithHigherPrecision().

    [4] You cannot directly Scan() into the alternative data types via snowflakeRows.Scan(), but can convert to those data types by using .Int64()/.String()/.Uint64() methods. For an example, see below.

    [5] You cannot directly Scan() into the alternative data types via snowflakeRows.Scan(), but can convert to those data types by using .Float32()/.String()/.Float64() methods. For an example, see below.

Note: SQL NULL values are converted to Golang nil values, and vice-versa.

The following example shows how to retrieve very large values using the math/big package. This example retrieves a large INTEGER value to an interface and then extracts a big.Int value from that interface. If the value fits into an int64, then the code also copies the value to a variable of type int64. Note that a context that enables higher precision must be passed in with the query. 

import "context"
import "math/big"

...

var my_interface interface{}
var my_big_int_pointer *big.Int
var my_int64 int64
var rows snowflakeRows

...
rows = db.QueryContext(WithHigherPrecision(context.Background), <query>)
rows.Scan(&my_interface)
my_big_int_pointer, ok = my_interface.(*big.Int)
if my_big_int_pointer.IsInt64() {
    my_int64 = my_big_int_pointer.Int64()
}

If the variable named "rows" is known to contain a big.Int, then you can use the following instead of scanning into an interface and then converting to a big.Int: 

rows.Scan(&my_big_int_pointer)

If the variable named "rows" contains a big.Int, then each of the following fails: 

rows.Scan(&my_int64)

my_int64, _ = my_interface.(int64)

Similar code and rules also apply to big.Float values.

If you are not sure what data type will be returned, you can use code similar to the following to check the data type of the returned value: 

// Create variables into which you can scan the returned values.
var i64 int64
var bigIntPtr *big.Int

for rows.Next() {
    // Get the data type info.
    column_types, err := rows.ColumnTypes()
    if err != nil {
        log.Fatalf("ERROR: ColumnTypes() failed. err: %v", err)
    }
    // The data type of the zeroeth column in the row.
    column_type := column_types[0].ScanType()
    // Choose the appropriate variable based on the data type.
    switch column_type {
        case reflect.TypeOf(i64):
            err = rows.Scan(&i64)
            fmt.Println("INFO: retrieved int64 value:")
            fmt.Println(i64)
        case reflect.TypeOf(bigIntPtr):
            err = rows.Scan(&bigIntPtr)
            fmt.Println("INFO: retrieved bigIntPtr value:")
            fmt.Println(bigIntPtr)
    }
}

Binding Parameters

Binding allows a SQL statement to use a value that is stored in a Golang variable.

Without binding, a SQL statement specifies values by specifying literals inside the statement. For example, the following statement uses the literal value “42“ in an UPDATE statement: 

_, err = db.Exec("UPDATE table1 SET integer_column = 42 WHERE ID = 1000")

With binding, you can execute a SQL statement that uses a value that is inside a variable. For example: 

var my_integer_variable int = 42
_, err = db.Exec("UPDATE table1 SET integer_column = ? WHERE ID = 1000", my_integer_variable)

The “?“ inside the “VALUES“ clause specifies that the SQL statement uses the value from a variable.

Binding data that involves time zones can require special handling. For details, see the section titled "Timestamps with Time Zones".

Binding Parameters to Array Variables

Version 1.3.9 (and later) of the Go Snowflake Driver supports the ability to bind an array variable to a parameter in a SQL INSERT statement. You can use this technique to insert multiple rows in a single batch.

As an example, the following code inserts rows into a table that contains integer, float, boolean, and string columns. The example binds arrays to the parameters in the INSERT statement. 

// Create a table containing an integer, float, boolean, and string column.
_, err = db.Exec("create or replace table my_table(c1 int, c2 float, c3 boolean, c4 string)")
...
// Define the arrays containing the data to insert.
intArray := []int{1, 2, 3}
fltArray := []float64{0.1, 2.34, 5.678}
boolArray := []bool{true, false, true}
strArray := []string{"test1", "test2", "test3"}
...
// Insert the data from the arrays and wrap in an Array() function into the table.
_, err = db.Exec("insert into my_table values (?, ?, ?, ?)", Array(&intArray), Array(&fltArray), Array(&boolArray), Array(&strArray))

Note: For alternative ways to load data into the Snowflake database (including bulk loading using the COPY command), see Loading Data into Snowflake (https://docs.snowflake.com/en/user-guide-data-load.html).

Batch Inserts and Binding Parameters

When you use array binding to insert a large number of values, the driver can improve performance by streaming the data (without creating files on the local machine) to a temporary stage for ingestion. The driver automatically does this when the number of values exceeds a threshold (no changes are needed to user code).

In order for the driver to send the data to a temporary stage, the user must have the following privilege on the schema: 

CREATE STAGE

If the user does not have this privilege, the driver falls back to sending the data with the query to the Snowflake database.

In addition, the current database and schema for the session must be set. If these are not set, the CREATE TEMPORARY STAGE command executed by the driver can fail with the following error: 

CREATE TEMPORARY STAGE SYSTEM$BIND file_format=(type=csv field_optionally_enclosed_by='"')
Cannot perform CREATE STAGE. This session does not have a current schema. Call 'USE SCHEMA', or use a qualified name.

For alternative ways to load data into the Snowflake database (including bulk loading using the COPY command), see Loading Data into Snowflake (https://docs.snowflake.com/en/user-guide-data-load.html).

Binding a Parameter to a Time Type

Go's database/sql package supports the ability to bind a parameter in a SQL statement to a time.Time variable. However, when the client binds data to send to the server, the driver cannot determine the correct Snowflake date/timestamp data type to associate with the binding parameter. For example: 

dbt.mustExec("CREATE OR REPLACE TABLE tztest (id int, ntz, timestamp_ntz, ltz timestamp_ltz)")
// ...
stmt, err :=dbt.db.Prepare("INSERT INTO tztest(id,ntz,ltz) VALUES(1, ?, ?)")
// ...
tmValue time.Now()
// ... Is tmValue a TIMESTAMP_NTZ or TIMESTAMP_LTZ?
_, err = stmt.Exec(tmValue, tmValue)

To resolve this issue, a binding parameter flag is introduced that associates any subsequent time.Time type to the DATE, TIME, TIMESTAMP_LTZ, TIMESTAMP_NTZ or BINARY data type. The above example could be rewritten as follows: 

import (
	sf "github.com/snowflakedb/gosnowflake"
)
dbt.mustExec("CREATE OR REPLACE TABLE tztest (id int, ntz, timestamp_ntz, ltz timestamp_ltz)")
// ...
stmt, err :=dbt.db.Prepare("INSERT INTO tztest(id,ntz,ltz) VALUES(1, ?, ?)")
// ...
tmValue time.Now()
// ...
_, err = stmt.Exec(sf.DataTypeTimestampNtz, tmValue, sf.DataTypeTimestampLtz, tmValue)

Timestamps with Time Zones

The driver fetches TIMESTAMP_TZ (timestamp with time zone) data using the offset-based Location types, which represent a collection of time offsets in use in a geographical area, such as CET (Central European Time) or UTC (Coordinated Universal Time). The offset-based Location data is generated and cached when a Go Snowflake Driver application starts, and if the given offset is not in the cache, it is generated dynamically.

Currently, Snowflake does not support the name-based Location types (e.g. "America/Los_Angeles").

For more information about Location types, see the Go documentation for https://golang.org/pkg/time/#Location.

Binary Data

Internally, this feature leverages the []byte data type. As a result, BINARY data cannot be bound without the binding parameter flag. In the following example, sf is an alias for the gosnowflake package: 

var b = []byte{0x01, 0x02, 0x03}
_, err = stmt.Exec(sf.DataTypeBinary, b)

Maximum Number of Result Set Chunk Downloader

The driver directly downloads a result set from the cloud storage if the size is large. It is required to shift workloads from the Snowflake database to the clients for scale. The download takes place by goroutine named "Chunk Downloader" asynchronously so that the driver can fetch the next result set while the application can consume the current result set.

The application may change the number of result set chunk downloader if required. Note this does not help reduce memory footprint by itself. Consider Custom JSON Decoder. 

import (
	sf "github.com/snowflakedb/gosnowflake"
)
sf.MaxChunkDownloadWorkers = 2

Custom JSON Decoder for Parsing Result Set (Experimental)

The application may have the driver use a custom JSON decoder that incrementally parses the result set as follows. 

import (
	sf "github.com/snowflakedb/gosnowflake"
)
sf.CustomJSONDecoderEnabled = true
...

This option will reduce the memory footprint to half or even quarter, but it can significantly degrade the performance depending on the environment. The test cases running on Travis Ubuntu box show five times less memory footprint while four times slower. Be cautious when using the option.

JWT authentication

The Go Snowflake Driver supports JWT (JSON Web Token) authentication.

To enable this feature, construct the DSN with fields "authenticator=SNOWFLAKE_JWT&privateKey=<your_private_key>", or using a Config structure specifying: 

config := &Config{
	...
	Authenticator: "SNOWFLAKE_JWT"
	PrivateKey:   "<your_private_key_struct in *rsa.PrivateKey type>"
}

The <your_private_key> should be a base64 URL encoded PKCS8 rsa private key string. One way to encode a byte slice to URL base 64 URL format is through the base64.URLEncoding.EncodeToString() function.

On the server side, you can alter the public key with the SQL command: 

ALTER USER <your_user_name> SET RSA_PUBLIC_KEY='<your_public_key>';

The <your_public_key> should be a base64 Standard encoded PKI public key string. One way to encode a byte slice to base 64 Standard format is through the base64.StdEncoding.EncodeToString() function.

To generate the valid key pair, you can execute the following commands in the shell: 

	# generate 2048-bit pkcs8 encoded RSA private key
	openssl genpkey -algorithm RSA \
    	-pkeyopt rsa_keygen_bits:2048 \
    	-pkeyopt rsa_keygen_pubexp:65537 | \
  		openssl pkcs8 -topk8 -outform der > rsa-2048-private-key.p8

	# extract 2048-bit PKI encoded RSA public key from the private key
	openssl pkey -pubout -inform der -outform der \
    	-in rsa-2048-private-key.p8 \
    	-out rsa-2048-public-key.spki

Note: As of February 2020, Golang's official library does not support passcode-encrypted PKCS8 private key. For security purposes, Snowflake highly recommends that you store the passcode-encrypted private key on the disk and decrypt the key in your application using a library you trust.

Executing Multiple Statements in One Call

This feature is available in version 1.3.8 or later of the driver.

By default, Snowflake returns an error for queries issued with multiple statements. This restriction helps protect against SQL Injection attacks (https://en.wikipedia.org/wiki/SQL_injection).

The multi-statement feature allows users skip this restriction and execute multiple SQL statements through a single Golang function call. However, this opens up the possibility for SQL injection, so it should be used carefully. The risk can be reduced by specifying the exact number of statements to be executed, which makes it more difficult to inject a statement by appending it. More details are below.

The Go Snowflake Driver provides two functions that can execute multiple SQL statements in a single call:

  • db.QueryContext(): This function is used to execute queries, such as SELECT statements, that return a result set.
  • db.ExecContext(): This function is used to execute statements that don't return a result set (i.e. most DML and DDL statements).

To compose a multi-statement query, simply create a string that contains all the queries, separated by semicolons, in the order in which the statements should be executed.

To protect against SQL Injection attacks while using the multi-statement feature, pass a Context that specifies the number of statements in the string. For example: 

import (
	"context"
	"database/sql"
)

var multi_statement_query = "SELECT c1 FROM t1; SELECT c2 FROM t2"
var number_of_statements = 2
blank_context = context.Background()
multi_statement_context, _ := WithMultiStatement(blank_context, number_of_statements)
rows, err := db.QueryContext(multi_statement_context, multi_statement_query)

When multiple queries are executed by a single call to QueryContext(), multiple result sets are returned. After you process the first result set, get the next result set (for the next SQL statement) by calling NextResultSet().

The following pseudo-code shows how to process multiple result sets: 

Execute the statement and get the result set(s):

	rows, err := db.QueryContext(ctx, multiStmtQuery)

Retrieve the rows in the first query's result set:

	while rows.Next() {
		err = rows.Scan(&variable_1)
		if err != nil {
			t.Errorf("failed to scan: %#v", err)
		}
		...
	}

Retrieve the remaining result sets and the rows in them:

	while rows.NextResultSet()  {

		while rows.Next() {
			...
		}

	}

The function db.ExecContext() returns a single result, which is the sum of the number of rows changed by each individual statement. For example, if your multi-statement query executed two UPDATE statements, each of which updated 10 rows, then the result returned would be 20. Individual row counts for individual statements are not available.

The following code shows how to retrieve the result of a multi-statement query executed through db.ExecContext(): 

Execute the SQL statements:

    res, err := db.ExecContext(ctx, multiStmtQuery)

Get the summed result and store it in the variable named count:

    count, err := res.RowsAffected()

Note: Because a multi-statement ExecContext() returns a single value, you cannot detect offsetting errors. For example, suppose you expected the return value to be 20 because you expected each UPDATE statement to update 10 rows. If one UPDATE statement updated 15 rows and the other UPDATE statement updated only 5 rows, the total would still be 20. You would see no indication that the UPDATES had not functioned as expected.

The ExecContext() function does not return an error if passed a query (e.g. a SELECT statement). However, it still returns only a single value, not a result set, so using it to execute queries (or a mix of queries and non-query statements) is impractical.

The QueryContext() function does not return an error if passed non-query statements (e.g. DML). The function returns a result set for each statement, whether or not the statement is a query. For each non-query statement, the result set contains a single row that contains a single column; the value is the number of rows changed by the statement.

If you want to execute a mix of query and non-query statements (e.g. a mix of SELECT and DML statements) in a multi-statement query, use QueryContext(). You can retrieve the result sets for the queries, and you can retrieve or ignore the row counts for the non-query statements.

Note: PUT statements are not supported for multi-statement queries.

If a SQL statement passed to ExecQuery() or QueryContext() fails to compile or execute, that statement is aborted, and subsequent statements are not executed. Any statements prior to the aborted statement are unaffected.

For example, if the statements below are run as one multi-statement query, the multi-statement query fails on the third statement, and an exception is thrown. 

CREATE OR REPLACE TABLE test(n int);
INSERT INTO TEST VALUES (1), (2);
INSERT INTO TEST VALUES ('not_an_integer');  -- execution fails here
INSERT INTO TEST VALUES (3);

If you then query the contents of the table named "test", the values 1 and 2 would be present.

When using the QueryContext() and ExecContext() functions, golang code can check for errors the usual way. For example: 

rows, err := db.QueryContext(ctx, multiStmtQuery)
if err != nil {
	Fatalf("failed to query multiple statements: %v", err)
}

Preparing statements and using bind variables are also not supported for multi-statement queries.

Asynchronous Queries

The Go Snowflake Driver supports asynchronous execution of SQL statements. Asynchronous execution allows you to start executing a statement and then retrieve the result later without being blocked while waiting. While waiting for the result of a SQL statement, you can perform other tasks, including executing other SQL statements.

Most of the steps to execute an asynchronous query are the same as the steps to execute a synchronous query. However, there is an additional step, which is that you must call the WithAsyncMode() function to update your Context object to specify that asynchronous mode is enabled.

In the code below, the call to "WithAsyncMode()" is specific to asynchronous mode. The rest of the code is compatible with both asynchronous mode and synchronous mode. 

...

// Update your Context object to specify asynchronous mode:
ctx := WithAsyncMode(context.Background())

// Execute your query as usual by calling:
rows, _ := db.QueryContext(ctx, query_string)

// Retrieve the results as usual by calling:
for rows.Next()  {
	err := rows.Scan(...)
	...
}

The function db.QueryContext() returns an object of type snowflakeRows regardless of whether the query is synchronous or asynchronous. However:

  • If the query is synchronous, then db.QueryContext() does not return until the query has finished and the result set has been loaded into the snowflakeRows object.
  • If the query is asynchronous, then db.QueryContext() returns a potentially incomplete snowflakeRows object that is filled in later in the background.

The call to the Next() function of snowflakeRows is always synchronous (i.e. blocking). If the query has not yet completed and the snowflakeRows object (named "rows" in this example) has not been filled in yet, then rows.Next() waits until the result set has been filled in.

More generally, calls to any Golang SQL API function implemented in snowflakeRows or snowflakeResult are blocking calls, and wait if results are not yet available. (Examples of other synchronous calls include: snowflakeRows.Err(), snowflakeRows.Columns(), snowflakeRows.columnTypes(), snowflakeRows.Scan(), and snowflakeResult.RowsAffected().)

Because the example code above executes only one query and no other activity, there is no significant difference in behavior between asynchronous and synchronous behavior. The differences become significant if, for example, you want to perform some other activity after the query starts and before it completes. The example code below starts multiple queries, which run in the background, and then retrieves the results later.

This example uses small SELECT statements that do not retrieve enough data to require asynchronous handling. However, the technique works for larger data sets, and for situations where the programmer might want to do other work after starting the queries and before retrieving the results. 

	package gosnowflake

	import  (
		"context"
		"database/sql"
		"database/sql/driver"
		"fmt"
		"log"
		"os"
		sf "github.com/snowflakedb/gosnowflake"
    )

	...

	func DemonstrateAsyncMode(db *sql.DB) {
		// Enable asynchronous mode.
		ctx := WithAsyncMode(context.Background())
		// Establish connection
		conn, _ := db.Conn(ctx)

		// Unwrap connection
		err = conn.Raw(func(x interface{}) error {
			// Execute asynchronous query
			rows, _ := x.(driver.QueryerContext).QueryContext(ctx, "select 1", nil)
			defer rows.Close()

			// Retrieve and check results of the query after casting the result
			status := rows.(SnowflakeResult).GetStatus()
			if status == QueryStatusComplete {
				// do something
			} else if status == QueryStatusInProgress {
				// do something
			} else if status == QueryFailed {
				// do something
			}
			return nil
		})
	}

Support For PUT and GET

The Go Snowflake Driver supports the PUT and GET commands.

The PUT command copies a file from a local computer (the computer where the Golang client is running) to a stage on the cloud platform. The GET command copies data files from a stage on the cloud platform to a local computer.

See the following for information on the syntax and supported parameters:

Using PUT

The following example shows how to run a PUT command by passing a string to the db.Query() function: 

db.Query("PUT file://<local_file> <stage_identifier> <optional_parameters>")

"<local_file>" should include the file path as well as the name. Snowflake recommends using an absolute path rather than a relative path. For example: 

db.Query("PUT file:///tmp/my_data_file @~ auto_compress=false overwrite=false")

Different client platforms (e.g. linux, Windows) have different path name conventions. Ensure that you specify path names appropriately. This is particularly important on Windows, which uses the backslash character as both an escape character and as a separator in path names.

To send information from a stream (rather than a file) use code similar to the code below. (The ReplaceAll() function is needed on Windows to handle backslashes in the path to the file.) 

fileStream, _ := os.OpenFile(fname, os.O_RDONLY, os.ModePerm)
defer func() {
	if fileStream != nil {
		fileStream.Close()
	}
} ()

sql := "put 'file://%v' @%%%v auto_compress=true parallel=30"
sqlText := fmt.Sprintf(sql,
	strings.ReplaceAll(fname, "\\", "\\\\"),
	tableName)
dbt.mustExecContext(WithFileStream(context.Background(), fileStream),
	sqlText)

Note: PUT statements are not supported for multi-statement queries.

Using GET

The following example shows how to run a GET command by passing a string to the db.Query() function: 

db.Query("GET file://<local_file> <stage_identifier> <optional_parameters>")

"<local_file>" should include the file path as well as the name. Snowflake recommends using an absolute path rather than a relative path. For example: 

db.Query("GET file:///tmp/my_data_file @~ auto_compress=false overwrite=false")

Index

Constants

View Source 
const (
	// TimestampNTZType denotes a NTZ timezoneType for array binds
	TimestampNTZType timezoneType = iota
	// TimestampLTZType denotes a LTZ timezoneType for array binds
	TimestampLTZType
	// TimestampTZType denotes a TZ timezoneType for array binds
	TimestampTZType
	// DateType denotes a date type for array binds
	DateType
	// TimeType denotes a time type for array binds
	TimeType
)
View Source 
const (

	// ErrCodeEmptyAccountCode is an error code for the case where a DNS doesn't include account parameter
	ErrCodeEmptyAccountCode = 260000
	// ErrCodeEmptyUsernameCode is an error code for the case where a DNS doesn't include user parameter
	ErrCodeEmptyUsernameCode = 260001
	// ErrCodeEmptyPasswordCode is an error code for the case where a DNS doesn't include password parameter
	ErrCodeEmptyPasswordCode = 260002
	// ErrCodeFailedToParseHost is an error code for the case where a DNS includes an invalid host name
	ErrCodeFailedToParseHost = 260003
	// ErrCodeFailedToParsePort is an error code for the case where a DNS includes an invalid port number
	ErrCodeFailedToParsePort = 260004
	// ErrCodeIdpConnectionError is an error code for the case where a IDP connection failed
	ErrCodeIdpConnectionError = 260005
	// ErrCodeSSOURLNotMatch is an error code for the case where a SSO URL doesn't match
	ErrCodeSSOURLNotMatch = 260006
	// ErrCodeServiceUnavailable is an error code for the case where service is unavailable.
	ErrCodeServiceUnavailable = 260007
	// ErrCodeFailedToConnect is an error code for the case where a DB connection failed due to wrong account name
	ErrCodeFailedToConnect = 260008
	// ErrCodeRegionOverlap is an error code for the case where a region is specified despite an account region present
	ErrCodeRegionOverlap = 260009
	// ErrCodePrivateKeyParseError is an error code for the case where the private key is not parsed correctly
	ErrCodePrivateKeyParseError = 260010
	// ErrCodeFailedToParseAuthenticator is an error code for the case where a DNS includes an invalid authenticator
	ErrCodeFailedToParseAuthenticator = 260011

	// ErrFailedToPostQuery is an error code for the case where HTTP POST failed.
	ErrFailedToPostQuery = 261000
	// ErrFailedToRenewSession is an error code for the case where session renewal failed.
	ErrFailedToRenewSession = 261001
	// ErrFailedToCancelQuery is an error code for the case where cancel query failed.
	ErrFailedToCancelQuery = 261002
	// ErrFailedToCloseSession is an error code for the case where close session failed.
	ErrFailedToCloseSession = 261003
	// ErrFailedToAuth is an error code for the case where authentication failed for unknown reason.
	ErrFailedToAuth = 261004
	// ErrFailedToAuthSAML is an error code for the case where authentication via SAML failed for unknown reason.
	ErrFailedToAuthSAML = 261005
	// ErrFailedToAuthOKTA is an error code for the case where authentication via OKTA failed for unknown reason.
	ErrFailedToAuthOKTA = 261006
	// ErrFailedToGetSSO is an error code for the case where authentication via OKTA failed for unknown reason.
	ErrFailedToGetSSO = 261007
	// ErrFailedToParseResponse is an error code for when we cannot parse an external browser response from Snowflake.
	ErrFailedToParseResponse = 261008
	// ErrFailedToGetExternalBrowserResponse is an error code for when there's an error reading from the open socket.
	ErrFailedToGetExternalBrowserResponse = 261009
	// ErrFailedToHeartbeat is an error code when a heartbeat fails.
	ErrFailedToHeartbeat = 261010

	// ErrFailedToGetChunk is an error code for the case where it failed to get chunk of result set
	ErrFailedToGetChunk = 262000

	// ErrNoReadOnlyTransaction is an error code for the case where readonly mode is specified.
	ErrNoReadOnlyTransaction = 263000
	// ErrNoDefaultTransactionIsolationLevel is an error code for the case where non default isolation level is specified.
	ErrNoDefaultTransactionIsolationLevel = 263001

	// ErrInvalidStageFs is an error code denoting an invalid stage in the file system
	ErrInvalidStageFs = 264001
	// ErrFailedToDownloadFromStage is an error code denoting the failure to download a file from the stage
	ErrFailedToDownloadFromStage = 264002
	// ErrFailedToUploadToStage is an error code denoting the failure to upload a file to the stage
	ErrFailedToUploadToStage = 264003
	// ErrInvalidStageLocation is an error code denoting an invalid stage location
	ErrInvalidStageLocation = 264004
	// ErrLocalPathNotDirectory is an error code denoting a local path that is not a directory
	ErrLocalPathNotDirectory = 264005
	// ErrFileNotExists is an error code denoting the file to be transferred does not exist
	ErrFileNotExists = 264006
	// ErrCompressionNotSupported is an error code denoting the user specified compression type is not supported
	ErrCompressionNotSupported = 264007
	// ErrInternalNotMatchEncryptMaterial is an error code denoting the encryption material specified does not match
	ErrInternalNotMatchEncryptMaterial = 264008
	// ErrCommandNotRecognized is an error code denoting the PUT/GET command was not recognized
	ErrCommandNotRecognized = 264009
	// ErrFailedToConvertToS3Client is an error code denoting the failure of an interface to s3.Client conversion
	ErrFailedToConvertToS3Client = 264010
	// ErrNotImplemented is an error code denoting the file transfer feature is not implemented
	ErrNotImplemented = 264011

	// ErrBindSerialization is an error code for a failed serialization of bind variables
	ErrBindSerialization = 265001
	// ErrBindUpload is an error code for the uploading process of bind elements to the stage
	ErrBindUpload = 265002

	// ErrAsync is an error code for an unknown async error
	ErrAsync = 266001

	// ErrNoResultIDs is an error code for empty result IDs for multi statement queries
	ErrNoResultIDs = 267001

	// ErrInvalidTimestampTz is an error code for the case where a returned TIMESTAMP_TZ internal value is invalid
	ErrInvalidTimestampTz = 268000
	// ErrInvalidOffsetStr is an error code for the case where a offset string is invalid. The input string must
	// consist of sHHMI where one sign character '+'/'-' followed by zero filled hours and minutes
	ErrInvalidOffsetStr = 268001
	// ErrInvalidBinaryHexForm is an error code for the case where a binary data in hex form is invalid.
	ErrInvalidBinaryHexForm = 268002

	// ErrOCSPStatusRevoked is an error code for the case where the certificate is revoked.
	ErrOCSPStatusRevoked = 269001
	// ErrOCSPStatusUnknown is an error code for the case where the certificate revocation status is unknown.
	ErrOCSPStatusUnknown = 269002
	// ErrOCSPInvalidValidity is an error code for the case where the OCSP response validity is invalid.
	ErrOCSPInvalidValidity = 269003
	// ErrOCSPNoOCSPResponderURL is an error code for the case where the OCSP responder URL is not attached.
	ErrOCSPNoOCSPResponderURL = 269004

	// ErrQueryStatus when check the status of a query, receive error or no status
	ErrQueryStatus = 279001
	// ErrQueryIDFormat the query ID given to fetch its result is not valid
	ErrQueryIDFormat = 279101
	// ErrQueryReportedError server side reports the query failed with error
	ErrQueryReportedError = 279201
	// ErrQueryIsRunning the query is still running
	ErrQueryIsRunning = 279301

	// ErrSessionGone is an GS error code for the case that session is already closed
	ErrSessionGone = 390111
	// ErrRoleNotExist is a GS error code for the case that the role specified does not exist
	ErrRoleNotExist = 390189
	// ErrObjectNotExistOrAuthorized is a GS error code for the case that the server-side object specified does not exist
	ErrObjectNotExistOrAuthorized = 390201
)
View Source 
const (
	SFQueryRunning queryResultStatus = iota
	SFQueryAborting
	SFQuerySuccess
	SFQueryFailedWithError
	SFQueryAborted
	SFQueryQueued
	SFQueryFailedWithIncident
	SFQueryDisconnected
	SFQueryResumingWarehouse
	// SFQueryQueueRepairingWarehouse present in QueryDTO.java.
	SFQueryQueueRepairingWarehouse
	SFQueryRestarted
	// SFQueryBlocked is when a statement is waiting on a lock on resource held
	// by another statement.
	SFQueryBlocked
	SFQueryNoData
)

Query Status defined at server side

View Source 
const (
	// QueryStatusInProgress denotes a query execution in progress
	QueryStatusInProgress queryStatus = "queryStatusInProgress"
	// QueryStatusComplete denotes a completed query execution
	QueryStatusComplete queryStatus = "queryStatusComplete"
	// QueryFailed denotes a failed query
	QueryFailed queryStatus = "queryFailed"
)
View Source 
const (
	// SQLStateNumericValueOutOfRange is a SQL State code indicating Numeric value is out of range.
	SQLStateNumericValueOutOfRange = "22003"
	// SQLStateInvalidDataTimeFormat is a SQL State code indicating DataTime format is invalid.
	SQLStateInvalidDataTimeFormat = "22007"
	// SQLStateConnectionWasNotEstablished is a SQL State code indicating connection was not established.
	SQLStateConnectionWasNotEstablished = "08001"
	// SQLStateConnectionRejected is a SQL State code indicating connection was rejected.
	SQLStateConnectionRejected = "08004"
	// SQLStateConnectionFailure is a SQL State code indicating connection failed.
	SQLStateConnectionFailure = "08006"
	// SQLStateFeatureNotSupported is a SQL State code indicating the feature is not enabled.
	SQLStateFeatureNotSupported = "0A000"
)
View Source 
const SFSessionIDKey contextKey = "LOG_SESSION_ID"

SFSessionIDKey is context key of session id

View Source 
const SFSessionUserKey contextKey = "LOG_USER"

SFSessionUserKey is context key of user id of a session

View Source 
const SnowflakeGoDriverVersion = "1.6.11"

SnowflakeGoDriverVersion is the version of Go Snowflake Driver.

Variables

View Source 
var (
	// DataTypeFixed is a FIXED datatype.
	DataTypeFixed = []byte{fixedType.Byte()}
	// DataTypeReal is a REAL datatype.
	DataTypeReal = []byte{realType.Byte()}
	// DataTypeText is a TEXT datatype.
	DataTypeText = []byte{textType.Byte()}
	// DataTypeDate is a Date datatype.
	DataTypeDate = []byte{dateType.Byte()}
	// DataTypeVariant is a TEXT datatype.
	DataTypeVariant = []byte{variantType.Byte()}
	// DataTypeTimestampLtz is a TIMESTAMP_LTZ datatype.
	DataTypeTimestampLtz = []byte{timestampLtzType.Byte()}
	// DataTypeTimestampNtz is a TIMESTAMP_NTZ datatype.
	DataTypeTimestampNtz = []byte{timestampNtzType.Byte()}
	// DataTypeTimestampTz is a TIMESTAMP_TZ datatype.
	DataTypeTimestampTz = []byte{timestampTzType.Byte()}
	// DataTypeObject is a OBJECT datatype.
	DataTypeObject = []byte{objectType.Byte()}
	// DataTypeArray is a ARRAY datatype.
	DataTypeArray = []byte{arrayType.Byte()}
	// DataTypeBinary is a BINARY datatype.
	DataTypeBinary = []byte{binaryType.Byte()}
	// DataTypeTime is a TIME datatype.
	DataTypeTime = []byte{timeType.Byte()}
	// DataTypeBoolean is a BOOLEAN datatype.
	DataTypeBoolean = []byte{booleanType.Byte()}
)
View Source 
var (
	// ErrEmptyAccount is returned if a DNS doesn't include account parameter.
	ErrEmptyAccount = &SnowflakeError{
		Number:  ErrCodeEmptyAccountCode,
		Message: "account is empty",
	}
	// ErrEmptyUsername is returned if a DNS doesn't include user parameter.
	ErrEmptyUsername = &SnowflakeError{
		Number:  ErrCodeEmptyUsernameCode,
		Message: "user is empty",
	}
	// ErrEmptyPassword is returned if a DNS doesn't include password parameter.
	ErrEmptyPassword = &SnowflakeError{
		Number:  ErrCodeEmptyPasswordCode,
		Message: "password is empty"}

	// ErrInvalidRegion is returned if a DSN's implicit region from account parameter and explicit region parameter conflict.
	ErrInvalidRegion = &SnowflakeError{
		Number:  ErrCodeRegionOverlap,
		Message: "two regions specified"}

	// ErrUnknownError is returned if the server side returns an error without meaningful message.
	ErrUnknownError = &SnowflakeError{
		Number:   -1,
		SQLState: "-1",
		Message:  "an unknown server side error occurred",
		QueryID:  "-1",
	}
)
View Source 
var (
	// MaxChunkDownloadWorkers specifies the maximum number of goroutines used to download chunks
	MaxChunkDownloadWorkers = 10

	// CustomJSONDecoderEnabled has the chunk downloader use the custom JSON decoder to reduce memory footprint.
	CustomJSONDecoderEnabled = false
)
View Source 
var LogKeys = [...]contextKey{SFSessionIDKey, SFSessionUserKey}

LogKeys these keys in context should be included in logging messages when using logger.WithContext

View Source 
var SnowflakeTransport = &http.Transport{
	TLSClientConfig: &tls.Config{
		RootCAs:               certPool,
		VerifyPeerCertificate: verifyPeerCertificateSerial,
	},
	MaxIdleConns:    10,
	IdleConnTimeout: 30 * time.Minute,
	Proxy:           http.ProxyFromEnvironment,
	DialContext: (&net.Dialer{
		Timeout:   30 * time.Second,
		KeepAlive: 30 * time.Second,
	}).DialContext,
}

SnowflakeTransport includes the certificate revocation check with OCSP in sequential. By default, the driver uses this transport object.

View Source 
var SnowflakeTransportTest = SnowflakeTransport

SnowflakeTransportTest includes the certificate revocation check in parallel

Functions

func Array added in v1.6.13 

func Array(a interface{}, typ ...timezoneType) interface{}

Array takes in a column of a row to be inserted via array binding, bulk or otherwise, and converts it into a native snowflake type for binding

func DSN 

func DSN(cfg *Config) (dsn string, err error)

DSN constructs a DSN for Snowflake db.

func Location 

func Location(offset int) *time.Location

Location returns an offset (minutes) based Location object for Snowflake database.

func LocationWithOffsetString 

func LocationWithOffsetString(offsets string) (loc *time.Location, err error)

LocationWithOffsetString returns an offset based Location object. The offset string must consist of sHHMI where one sign character '+'/'-' followed by zero filled hours and minutes.

func SFCallerPrettyfier added in v1.6.13 

func SFCallerPrettyfier(frame *runtime.Frame) (string, string)

SFCallerPrettyfier to provide base file name and function name from calling frame used in SFLogger

func SetLogger added in v1.6.13 

func SetLogger(inLogger *SFLogger)

SetLogger set a new logger of SFLogger interface for gosnowflake

func WithArrowBatches added in v1.6.13 

func WithArrowBatches(ctx context.Context) context.Context

WithArrowBatches returns a context that allows users to retrieve array.Record download workers upon querying

func WithAsyncMode added in v1.6.13 

func WithAsyncMode(ctx context.Context) context.Context

WithAsyncMode returns a context that allows execution of query in async mode

func WithDescribeOnly added in v1.6.13 

func WithDescribeOnly(ctx context.Context) context.Context

WithDescribeOnly returns a context that enables a describe only query

func WithFetchResultByID added in v1.6.13 

func WithFetchResultByID(ctx context.Context, queryID string) context.Context

WithFetchResultByID returns a context that allows retrieving the result by query ID

func WithFileStream added in v1.6.13 

func WithFileStream(ctx context.Context, reader io.Reader) context.Context

WithFileStream returns a context that contains the address of the file stream to be PUT

func WithFileTransferOptions added in v1.6.13 

func WithFileTransferOptions(ctx context.Context, options *SnowflakeFileTransferOptions) context.Context

WithFileTransferOptions returns a context that contains the address of file transfer options

func WithHigherPrecision added in v1.6.13 

func WithHigherPrecision(ctx context.Context) context.Context

WithHigherPrecision returns a context that enables higher precision by returning a *big.Int or *big.Float variable when querying rows for column types with numbers that don't fit into its native Golang counterpart

func WithMultiStatement added in v1.6.13 

func WithMultiStatement(ctx context.Context, num int) (context.Context, error)

WithMultiStatement returns a context that allows the user to execute the desired number of sql queries in one query

func WithQueryIDChan added in v1.6.13 

func WithQueryIDChan(ctx context.Context, c chan<- string) context.Context

WithQueryIDChan returns a context that contains the channel to receive the query ID

func WithRequestID added in v1.6.13 

func WithRequestID(ctx context.Context, requestID UUID) context.Context

WithRequestID returns a new context with the specified snowflake request id

func WithStreamDownloader added in v1.6.13 

func WithStreamDownloader(ctx context.Context) context.Context

WithStreamDownloader returns a context that allows the use of a stream based chunk downloader

Types

type ArrowBatch added in v1.6.13 

type ArrowBatch struct {
	// contains filtered or unexported fields
}

ArrowBatch object represents a chunk of data, or subset of rows, retrievable in array.Record format

func (*ArrowBatch) Fetch added in v1.6.13 

func (rb *ArrowBatch) Fetch() (*[]array.Record, error)

Fetch returns an array of records representing a chunk in the query

type AuthType added in v1.1.19 

type AuthType int

AuthType indicates the type of authentication in Snowflake 

const (
	// AuthTypeSnowflake is the general username password authentication
	AuthTypeSnowflake AuthType = iota
	// AuthTypeOAuth is the OAuth authentication
	AuthTypeOAuth
	// AuthTypeExternalBrowser is to use a browser to access an Fed and perform SSO authentication
	AuthTypeExternalBrowser
	// AuthTypeOkta is to use a native okta URL to perform SSO authentication on Okta
	AuthTypeOkta
	// AuthTypeJwt is to use Jwt to perform authentication
	AuthTypeJwt
	// AuthTypeKMSJwt is to use KMS Key to sign and create Jwt to perform authentication
	AuthTypeKMSJwt
	// AuthTypeTokenAccessor is to use the provided token accessor and bypass authentication
	AuthTypeTokenAccessor
)

func (AuthType) String added in v1.1.19 

func (authType AuthType) String() string

type Config 

type Config struct {
	Account   string // Account name
	User      string // Username
	Password  string // Password (requires User)
	Database  string // Database name
	Schema    string // Schema
	Warehouse string // Warehouse
	Role      string // Role
	Region    string // Region

	// ValidateDefaultParameters disable the validation checks for Database, Schema, Warehouse and Role
	// at the time a connection is established
	ValidateDefaultParameters ConfigBool

	Params map[string]*string // other connection parameters

	ClientIP net.IP // IP address for network check
	Protocol string // http or https (optional)
	Host     string // hostname (optional)
	Port     int    // port (optional)

	Authenticator AuthType // The authenticator type

	Passcode           string
	PasscodeInPassword bool

	OktaURL *url.URL

	LoginTimeout     time.Duration // Login retry timeout EXCLUDING network roundtrip and read out http response
	RequestTimeout   time.Duration // request retry timeout EXCLUDING network roundtrip and read out http response
	JWTExpireTimeout time.Duration // JWT expire after timeout
	ClientTimeout    time.Duration // Timeout for network round trip + read out http response

	Application  string           // application name.
	InsecureMode bool             // driver doesn't check certificate revocation status
	OCSPFailOpen OCSPFailOpenMode // OCSP Fail Open

	Token            string        // Token to use for OAuth other forms of token based auth
	TokenAccessor    TokenAccessor // Optional token accessor to use
	KeepSessionAlive bool          // Enables the session to persist even after the connection is closed

	PrivateKey *rsa.PrivateKey // Private key used to sign JWT

	Transporter http.RoundTripper // RoundTripper to intercept HTTP requests and responses

	DisableTelemetry bool // indicates whether to disable telemetry

	AWSKMSKeyARN string // KMS Arn used to sign the JWT.
}

Config is a set of configuration parameters

func ParseDSN 

func ParseDSN(dsn string) (cfg *Config, err error)

ParseDSN parses the DSN string to a Config.

type ConfigBool added in v1.3.0 

type ConfigBool uint8

ConfigBool is a type to represent true or false in the Config 

const (

	// ConfigBoolTrue represents true for the config field
	ConfigBoolTrue ConfigBool
	// ConfigBoolFalse represents false for the config field
	ConfigBoolFalse
)

type Connector added in v1.6.13 

type Connector struct {
	// contains filtered or unexported fields
}

Connector creates Driver with the specified Config

func NewConnector added in v1.6.13 

func NewConnector(driver InternalSnowflakeDriver, config Config) Connector

NewConnector creates a new connector with the given SnowflakeDriver and Config.

func (Connector) Connect added in v1.6.13 

func (t Connector) Connect(ctx context.Context) (driver.Conn, error)

Connect creates a new connection.

func (Connector) Driver added in v1.6.13 

func (t Connector) Driver() driver.Driver

Driver creates a new driver.

type InternalClient added in v1.6.13 

type InternalClient interface {
	Get(context.Context, *url.URL, map[string]string, time.Duration) (*http.Response, error)
	Post(context.Context, *url.URL, map[string]string, []byte, time.Duration, bool) (*http.Response, error)
}

InternalClient is implemented by HTTPClient

type InternalSnowflakeDriver added in v1.6.13 

type InternalSnowflakeDriver interface {
	Open(dsn string) (driver.Conn, error)
	OpenWithConfig(ctx context.Context, config Config) (driver.Conn, error)
}

InternalSnowflakeDriver is the interface for an internal Snowflake driver

type OCSPFailOpenMode added in v1.2.0 

type OCSPFailOpenMode uint32

OCSPFailOpenMode is OCSP fail open mode. OCSPFailOpenTrue by default and may set to ocspModeFailClosed for fail closed mode 

const (

	// OCSPFailOpenTrue represents OCSP fail open mode.
	OCSPFailOpenTrue OCSPFailOpenMode
	// OCSPFailOpenFalse represents OCSP fail closed mode.
	OCSPFailOpenFalse
)

type SFLogger added in v1.6.13 

type SFLogger interface {
	rlog.Ext1FieldLogger
	SetLogLevel(level string) error
	WithContext(ctx context.Context) *rlog.Entry
	SetOutput(output io.Writer)
}

SFLogger Snowflake logger interface to expose FieldLogger defined in logrus

func CreateDefaultLogger added in v1.6.13 

func CreateDefaultLogger() SFLogger

CreateDefaultLogger return a new instance of SFLogger with default config

func GetLogger added in v1.6.13 

func GetLogger() SFLogger

GetLogger return logger that is not public

type SnowflakeConnection added in v1.6.13 

type SnowflakeConnection interface {
	GetQueryStatus(ctx context.Context, queryID string) (*SnowflakeQueryStatus, error)
}

SnowflakeConnection is a wrapper to snowflakeConn that exposes API functions

type SnowflakeDriver 

type SnowflakeDriver struct{}

SnowflakeDriver is a context of Go Driver

func (SnowflakeDriver) Open 

func (d SnowflakeDriver) Open(dsn string) (driver.Conn, error)

Open creates a new connection.

func (SnowflakeDriver) OpenWithConfig added in v1.6.13 

func (d SnowflakeDriver) OpenWithConfig(
	ctx context.Context,
	config Config) (
	driver.Conn, error)

OpenWithConfig creates a new connection with the given Config.

type SnowflakeError 

type SnowflakeError struct {
	Number         int
	SQLState       string
	QueryID        string
	Message        string
	MessageArgs    []interface{}
	IncludeQueryID bool // TODO: populate this in connection
}

SnowflakeError is a error type including various Snowflake specific information.

func (*SnowflakeError) Error 

func (se *SnowflakeError) Error() string

type SnowflakeFileTransferOptions added in v1.6.13 

type SnowflakeFileTransferOptions struct {
	RaisePutGetError   bool
	MultiPartThreshold int64

	/* PUT */
	DisablePutOverwrite bool
	// contains filtered or unexported fields
}

SnowflakeFileTransferOptions enables users to specify options regarding files transfers such as PUT/GET

type SnowflakeParameter added in v1.1.10 

type SnowflakeParameter struct {
	Key                       string
	Value                     string
	Default                   string
	Level                     string
	Description               string
	SetByUser                 string
	SetInJob                  string
	SetOn                     string
	SetByThreadID             string
	SetByThreadName           string
	SetByClass                string
	ParameterComment          string
	Type                      string
	IsExpired                 string
	ExpiresAt                 string
	SetByControllingParameter string
	ActivateVersion           string
	PartialRollout            string
	Unknown                   string // Reserve for added parameter
}

SnowflakeParameter includes the columns output from SHOW PARAMETER command.

func ScanSnowflakeParameter added in v1.1.10 

func ScanSnowflakeParameter(rows *sql.Rows) (*SnowflakeParameter, error)

ScanSnowflakeParameter binds SnowflakeParameter variable with an array of column buffer.

type SnowflakeQueryStatus added in v1.6.13 

type SnowflakeQueryStatus struct {
	SQLText      string
	StartTime    int64
	EndTime      int64
	ErrorCode    string
	ErrorMessage string
	ScanBytes    int64
	ProducedRows int64
}

SnowflakeQueryStatus is the query status metadata of a snowflake query

type SnowflakeResult added in v1.6.13 

type SnowflakeResult interface {
	GetQueryID() string
	GetStatus() queryStatus
	GetArrowBatches() ([]*ArrowBatch, error)
}

SnowflakeResult provides an API for methods exposed to the clients

type TokenAccessor added in v1.6.13 

type TokenAccessor interface {
	GetTokens() (token string, masterToken string, sessionID int64)
	SetTokens(token string, masterToken string, sessionID int64)
	Lock() error
	Unlock()
}

TokenAccessor manages the session token and master token

type UUID added in v1.6.13 

type UUID [16]byte

UUID is a RFC4122 compliant uuid type

func NewUUID added in v1.6.13 

func NewUUID() UUID

NewUUID creates a new snowflake UUID

func ParseUUID added in v1.6.13 

func ParseUUID(str string) UUID

ParseUUID parses a string of xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx into its UUID form

func (UUID) String added in v1.6.13 

func (u UUID) String() string

Source Files

View all Source files

Directories

Path Synopsis
benchmark
jsonresultset
Package jsonresultset is a benchmark for large json result sets
 Package jsonresultset is a benchmark for large json result sets
largesetresult
Package largesetresult is a benchmark for large result sets
 Package largesetresult is a benchmark for large result sets
cmd
externalbrowser
keepalive
Example: client session keep alive By default, the token expires in 4 hours if the connection is idle.
 Example: client session keep alive By default, the token expires in 4 hours if the connection is idle.
logger
noconnpool
Example: No connection pool
 Example: No connection pool
oauth
Example: Authenticate with OAuth.
 Example: Authenticate with OAuth.
select1
Example: Fetch one row.
 Example: Fetch one row.
selectmany
Example: Fetch many rows and allow cancel the query by Ctrl+C.
 Example: Fetch many rows and allow cancel the query by Ctrl+C.
showparam
Example: Set the session parameter in DSN and verify it
 Example: Set the session parameter in DSN and verify it
verifycert
Example: Verify SSL/TLS certificate with OCSP revocation check
 Example: Verify SSL/TLS certificate with OCSP revocation check

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