mongo

package
v0.0.2 Latest Latest
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 Go to latest Published: Mar 6, 2018 License: Apache-2.0 Imports: 19 Imported by: 0

Documentation

Overview

Package mongo provides a MongoDB Driver API for Go.

Basic usage of the driver starts with creating a Client from a connection string. To do so, call the NewClient function: 

client, err := mongo.NewClient("mongodb://foo:bar@localhost:27017")
if err != nil { log.Fatal(err) }

This will create a new client and start monitoring the MongoDB server on localhost. The Database and Collection types can be used to access the database: 

collection := client.Database("baz").Collection("qux")

A Collection can be used to query the database or insert documents: 

res, err := collection.InsertOne(context.Background(), map[string]string{"hello": "world"})
if err != nil { log.Fatal(err) }
id := res.InsertedID

Several methods return a cursor, which can be used like this: 

cur, err := collection.Find(context.Background(), nil)
if err != nil { log.Fatal(err) }
defer cur.Close(context.Background())
for cur.Next(context.Background()) {
   elem := bson.NewDocument()
   err := cur.Decode(elem)
   if err != nil { log.Fatal(err) }
   // do something with elem....
}
if err := cur.Err(); err != nil {
    log.Fatal(err)
}

Methods that only return a single document will return a *DocumentResult, which works like a *sql.Row: 

result := bson.NewDocument()
filter := bson.NewDocument(bson.EC.String("hello", "world"))
err := collection.FindOne(context.Background(), filter).Decode(result)
if err != nil { log.Fatal(err) }
// do something with result...

Additional examples can be found under the examples directory in the driver's repository and on the MongoDB website.

Index

Constants

This section is empty.

Variables

View Source 
var ErrMissingResumeToken = errors.New("cannot provide resume functionality when the resume token is missing")

ErrMissingResumeToken indicates that a change stream notification from the server did not contain a resume token.

View Source 
var ErrNoDocuments = errors.New("mongo: no documents in result")

ErrNoDocuments is returned by Decode when an operation that returns a DocumentResult doesn't return any documents.

Functions

func TransformDocument 

func TransformDocument(document interface{}) (*bson.Document, error)

TransformDocument handles transforming a document of an allowable type into a *bson.Document. This method is called directly after most methods that have one or more parameters that are documents.

The supported types for document are: 

bson.Marshaler
bson.DocumentMarshaler
bson.Reader
[]byte (must be a valid BSON document)
io.Reader (only 1 BSON document will be read)
A custom struct type

Types

type Client 

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

Client performs operations on a given cluster.

func NewClient 

func NewClient(uri string) (*Client, error)

NewClient creates a new client to connect to a cluster specified by the uri.

func NewClientFromConnString 

func NewClientFromConnString(cs connstring.ConnString) (*Client, error)

NewClientFromConnString creates a new client to connect to a cluster specified by the connection string.

func (*Client) ConnectionString 

func (client *Client) ConnectionString() string

ConnectionString returns the connection string of the cluster the client is connected to.

func (*Client) Database 

func (client *Client) Database(name string) *Database

Database returns a handle for a given database.

type Collection 

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

Collection performs operations on a given collection.

func (*Collection) Aggregate 

func (coll *Collection) Aggregate(ctx context.Context, pipeline interface{},
	opts ...options.AggregateOptioner) (Cursor, error)

Aggregate runs an aggregation framework pipeline. A user can supply a custom context to this method.

See https://docs.mongodb.com/manual/aggregation/.

This method uses TransformDocument to turn the pipeline parameter into a *bson.Document. See TransformDocument for the list of valid types for pipeline.

func (*Collection) Count 

func (coll *Collection) Count(ctx context.Context, filter interface{},
	options ...options.CountOptioner) (int64, error)

Count gets the number of documents matching the filter. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter parameter into a *bson.Document. See TransformDocument for the list of valid types for filter.

func (*Collection) DeleteMany 

func (coll *Collection) DeleteMany(ctx context.Context, filter interface{},
	opts ...options.DeleteOptioner) (*DeleteResult, error)

DeleteMany deletes multiple documents from the collection. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter parameter into a *bson.Document. See TransformDocument for the list of valid types for filter.

func (*Collection) DeleteOne 

func (coll *Collection) DeleteOne(ctx context.Context, filter interface{},
	opts ...options.DeleteOptioner) (*DeleteResult, error)

DeleteOne deletes a single document from the collection. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter parameter into a *bson.Document. See TransformDocument for the list of valid types for filter.

func (*Collection) Distinct 

func (coll *Collection) Distinct(ctx context.Context, fieldName string, filter interface{},
	options ...options.DistinctOptioner) ([]interface{}, error)

Distinct finds the distinct values for a specified field across a single collection. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter parameter into a *bson.Document. See TransformDocument for the list of valid types for filter.

func (*Collection) Find 

func (coll *Collection) Find(ctx context.Context, filter interface{},
	options ...options.FindOptioner) (Cursor, error)

Find finds the documents matching a model. A user can supply a custom context to this method.

This method uses TransformDocument to turn the filter parameter into a *bson.Document. See TransformDocument for the list of valid types for filter.

func (*Collection) FindOne 

func (coll *Collection) FindOne(ctx context.Context, filter interface{},
	opts ...options.FindOneOptioner) *DocumentResult

FindOne returns up to one document that matches the model. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter parameter into a *bson.Document. See TransformDocument for the list of valid types for filter.

func (*Collection) FindOneAndDelete 

func (coll *Collection) FindOneAndDelete(ctx context.Context, filter interface{},
	opts ...options.FindOneAndDeleteOptioner) *DocumentResult

FindOneAndDelete find a single document and deletes it, returning the original in result. The document to return may be nil.

A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter parameter into a *bson.Document. See TransformDocument for the list of valid types for filter.

func (*Collection) FindOneAndReplace 

func (coll *Collection) FindOneAndReplace(ctx context.Context, filter interface{},
	replacement interface{}, opts ...options.FindOneAndReplaceOptioner) *DocumentResult

FindOneAndReplace finds a single document and replaces it, returning either the original or the replaced document. The document to return may be nil.

A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter and replacement parameter into a *bson.Document. See TransformDocument for the list of valid types for filter and replacement.

func (*Collection) FindOneAndUpdate 

func (coll *Collection) FindOneAndUpdate(ctx context.Context, filter interface{},
	update interface{}, opts ...options.FindOneAndUpdateOptioner) *DocumentResult

FindOneAndUpdate finds a single document and updates it, returning either the original or the updated. The document to return may be nil.

A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter and update parameter into a *bson.Document. See TransformDocument for the list of valid types for filter and update.

func (*Collection) InsertMany 

func (coll *Collection) InsertMany(ctx context.Context, documents []interface{},
	opts ...options.InsertManyOptioner) (*InsertManyResult, error)

InsertMany inserts the provided documents. A user can supply a custom context to this method.

Currently, batching is not implemented for this operation. Because of this, extremely large sets of documents will not fit into a single BSON document to be sent to the server, so the operation will fail.

This method uses TransformDocument to turn the documents parameter into a *bson.Document. See TransformDocument for the list of valid types for documents.

func (*Collection) InsertOne 

func (coll *Collection) InsertOne(ctx context.Context, document interface{},
	opts ...options.InsertOneOptioner) (*InsertOneResult, error)

InsertOne inserts a single document into the collection. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the document parameter into a *bson.Document. See TransformDocument for the list of valid types for document.

TODO(skriptble): Determine if we should unwrap the value for the InsertOneResult or just return the bson.Element or a bson.Value.

func (*Collection) ReplaceOne 

func (coll *Collection) ReplaceOne(ctx context.Context, filter interface{},
	replacement interface{}, opts ...options.ReplaceOptioner) (*UpdateResult, error)

ReplaceOne replaces a single document in the collection. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter and replacement parameter into a *bson.Document. See TransformDocument for the list of valid types for filter and replacement.

func (*Collection) UpdateMany 

func (coll *Collection) UpdateMany(ctx context.Context, filter interface{}, update interface{},
	opts ...options.UpdateOptioner) (*UpdateResult, error)

UpdateMany updates multiple documents in the collection. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter and update parameter into a *bson.Document. See TransformDocument for the list of valid types for filter and update.

func (*Collection) UpdateOne 

func (coll *Collection) UpdateOne(ctx context.Context, filter interface{}, update interface{},
	options ...options.UpdateOptioner) (*UpdateResult, error)

UpdateOne updates a single document in the collection. A user can supply a custom context to this method, or nil to default to context.Background().

This method uses TransformDocument to turn the filter and update parameter into a *bson.Document. See TransformDocument for the list of valid types for filter and update.

func (*Collection) Watch added in v0.0.2 

func (coll *Collection) Watch(ctx context.Context, pipeline interface{},
	opts ...options.ChangeStreamOptioner) (Cursor, error)

Watch returns a change stream cursor used to receive notifications of changes to the collection. This method is preferred to running a raw aggregation with a $changeStream stage because it supports resumability in the case of some errors.

type Cursor 

type Cursor interface {

	// Get the ID of the cursor.
	ID() int64

	// Get the next result from the cursor.
	// Returns true if there were no errors and there is a next result.
	Next(context.Context) bool

	Decode(interface{}) error

	DecodeBytes() (bson.Reader, error)

	// Returns the error status of the cursor
	Err() error

	// Close the cursor.
	Close(context.Context) error
}

Cursor instances iterate a stream of documents. Each document is decoded into the result according to the rules of the bson package.

A typical usage of the Cursor interface would be: 

var cur Cursor
ctx := context.Background()
defer cur.Close(ctx)

for cur.Next(ctx) {
	elem := bson.NewDocument()
	if err := cur.Decode(elem); err != nil {
		log.Fatal(err)
	}

	// do something with elem....
}

if err := cur.Err(); err != nil {
	log.Fatal(err)
}

type Database 

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

Database performs operations on a given database.

func (*Database) Client 

func (db *Database) Client() *Client

Client returns the Client the database was created from.

func (*Database) Collection 

func (db *Database) Collection(name string) *Collection

Collection gets a handle for a given collection in the database.

func (*Database) Name 

func (db *Database) Name() string

Name returns the name of the database.

func (*Database) RunCommand 

func (db *Database) RunCommand(ctx context.Context, command interface{}) (bson.Reader, error)

RunCommand runs a command on the database. A user can supply a custom context to this method, or nil to default to context.Background().

type DeleteResult 

type DeleteResult struct {
	// The number of documents that were deleted.
	DeletedCount int64 `bson:"n"`
}

DeleteResult is a result of an DeleteOne operation.

type DocumentResult 

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

DocumentResult represents a single document returned from an operation. If the operation returned an error, the Err method of DocumentResult will return that error.

func (*DocumentResult) Decode 

func (dr *DocumentResult) Decode(v interface{}) error

Decode will attempt to decode the first document into v. If there was an error from the operation that created this DocumentResult then the error will be returned. If there were no returned documents, ErrNoDocuments is returned.

type InsertManyResult 

type InsertManyResult struct {
	// Maps the indexes of inserted documents to their _id fields.
	InsertedIDs []interface{}
}

InsertManyResult is a result of an InsertMany operation.

type InsertOneResult 

type InsertOneResult struct {
	// The identifier that was inserted.
	InsertedID interface{}
}

InsertOneResult is a result of an InsertOne operation.

InsertedID will be a Go type that corresponds to a BSON type.

type Options added in v0.0.2 

type Options struct{}

Options is used as a namespace for MongoDB operation option constructors. 

var Opt Options

Opt is a convenience variable provided for access to Options methods.

func (Options) AllowDiskUse added in v0.0.2 

func (Options) AllowDiskUse(b bool) options.OptAllowDiskUse

AllowDiskUse enables writing to temporary files.

func (Options) AllowPartialResults added in v0.0.2 

func (Options) AllowPartialResults(b bool) options.OptAllowPartialResults

AllowPartialResults gets partial results from a mongos if some shards are down (instead of throwing an error).

func (Options) ArrayFilters added in v0.0.2 

func (Options) ArrayFilters(filters ...interface{}) (options.OptArrayFilters, error)

ArrayFilters specifies to which array elements an update should apply.

This function uses TransformDocument to turn the document parameter into a *bson.Document. See TransformDocument for the list of valid types for document.

func (Options) BatchSize added in v0.0.2 

func (Options) BatchSize(i int32) options.OptBatchSize

BatchSize specifies the number of documents to return per batch.

func (Options) BypassDocumentValidation added in v0.0.2 

func (Options) BypassDocumentValidation(b bool) options.OptBypassDocumentValidation

BypassDocumentValidation is used to opt out of document-level validation for a given write.

func (Options) Collation added in v0.0.2 

func (Options) Collation(collation *options.Collation) options.OptCollation

Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks.

See https://docs.mongodb.com/manual/reference/collation/.

func (Options) Comment added in v0.0.2 

func (Options) Comment(s string) options.OptComment

Comment specifies a comment to attach to the query to help attach and trace profile data.

See https://docs.mongodb.com/manual/reference/command/profile.

func (Options) CursorType added in v0.0.2 

func (Options) CursorType(cursorType options.CursorType) options.OptCursorType

CursorType indicates the type of cursor to use.

func (Options) FullDocument added in v0.0.2 

func (Options) FullDocument(fullDocument string) options.OptFullDocument

FullDocument indicates which changes should be returned in a change stream notification.

If fullDocument is "updateLookup", then the change notification for partial updates will include both a delta describing the changes to the document as well as a copy of the entire document that was changed from some time after the change occurred.

func (Options) Hint added in v0.0.2 

func (Options) Hint(hint interface{}) (options.OptHint, error)

Hint specifies the index to use.

The hint parameter must be either a string or a document. If it is a document, this func (Options)tion uses TransformDocument to turn the document into a *bson.Document. See TransformDocument for the list of valid types.

func (Options) Limit added in v0.0.2 

func (Options) Limit(i int64) options.OptLimit

Limit specifies the maximum number of documents to return.

func (Options) Max added in v0.0.2 

func (Options) Max(max interface{}) (options.OptMax, error)

Max specifies the exclusive upper bound for a specific index.

This function uses TransformDocument to turn the max parameter into a *bson.Document. See TransformDocument for the list of valid types for max.

func (Options) MaxAwaitTime added in v0.0.2 

func (Options) MaxAwaitTime(duration time.Duration) options.OptMaxAwaitTime

MaxAwaitTime specifies the maximum amount of time for the server to wait on new documents to satisfy a tailable-await cursor query.

func (Options) MaxScan added in v0.0.2 

func (Options) MaxScan(i int64) options.OptMaxScan

MaxScan specifies the maximum number of documents or index keys to scan when executing the query.

func (Options) MaxTime added in v0.0.2 

func (Options) MaxTime(duration time.Duration) options.OptMaxTime

MaxTime specifies the maximum amount of time to allow the query to run.

func (Options) Min added in v0.0.2 

func (Options) Min(min interface{}) (options.OptMin, error)

Min specifies the inclusive lower bound for a specific index.

This function uses TransformDocument to turn the min parameter into a *bson.Document. See TransformDocument for the list of valid types for min.

func (Options) NoCursorTimeout added in v0.0.2 

func (Options) NoCursorTimeout(b bool) options.OptNoCursorTimeout

NoCursorTimeout specifies whether to prevent the server from timing out idle cursors after an inactivity period.

func (Options) OplogReplay added in v0.0.2 

func (Options) OplogReplay(b bool) options.OptOplogReplay

OplogReplay is for internal replication use only.

func (Options) Ordered added in v0.0.2 

func (Options) Ordered(b bool) options.OptOrdered

Ordered specifies whether the remaining writes should be aborted if one of the earlier ones fails.

func (Options) Projection added in v0.0.2 

func (Options) Projection(projection interface{}) (options.OptProjection, error)

Projection limits the fields to return for all matching documents.

This function uses TransformDocument to turn the projection parameter into a *bson.Document. See TransformDocument for the list of valid types for projection.

func (Options) ReadConcern added in v0.0.2 

func (Options) ReadConcern(readConcern *readconcern.ReadConcern) (options.OptReadConcern, error)

ReadConcern for replica sets and replica set shards determines which data to return from a query.

func (Options) ResumeAfter added in v0.0.2 

func (Options) ResumeAfter(token *bson.Document) options.OptResumeAfter

ResumeAfter specifies the logical starting point for a new change stream.

func (Options) ReturnDocument added in v0.0.2 

func (Options) ReturnDocument(returnDocument options.ReturnDocument) options.OptReturnDocument

ReturnDocument specifies whether a findAndUpdate should return the document as it was before the update or as it is after.

func (Options) ReturnKey added in v0.0.2 

func (Options) ReturnKey(b bool) options.OptReturnKey

ReturnKey specifies whether to only return the index keys in the resulting documents.

func (Options) ShowRecordID added in v0.0.2 

func (Options) ShowRecordID(b bool) options.OptShowRecordID

ShowRecordID determines whether to return the record identifier for each document.

func (Options) Skip added in v0.0.2 

func (Options) Skip(i int64) options.OptSkip

Skip specifies the number of documents to skip before returning.

func (Options) Snapshot added in v0.0.2 

func (Options) Snapshot(b bool) options.OptSnapshot

Snapshot specifies whether to prevent the cursor from returning a document more than once because of an intervening write operation.

func (Options) Sort added in v0.0.2 

func (Options) Sort(sort interface{}) (options.OptSort, error)

Sort specifies order in which to return matching documents.

This function uses TransformDocument to turn the sort parameter into a *bson.Document. See TransformDocument for the list of valid types for sort.

func (Options) Upsert added in v0.0.2 

func (Options) Upsert(b bool) options.OptUpsert

Upsert specifies that a new document should be inserted if no document matches the update filter.

func (Options) WriteConcern added in v0.0.2 

func (Options) WriteConcern(writeConcern *writeconcern.WriteConcern) (options.OptWriteConcern, error)

WriteConcern describes the level of acknowledgement requested from MongoDB for write operations to a standalone mongod or to replica sets or to sharded clusters.

type UpdateResult 

type UpdateResult struct {
	// The number of documents that matched the filter.
	MatchedCount int64
	// The number of documents that were modified.
	ModifiedCount int64
	// The identifier of the inserted document if an upsert took place.
	UpsertedID interface{}
}

UpdateResult is a result of an update operation.

UpsertedID will be a Go type that corresponds to a BSON type.

func (*UpdateResult) UnmarshalBSON 

func (result *UpdateResult) UnmarshalBSON(b []byte) error

UnmarshalBSON implements the bson.Unmarshaler interface.

Source Files

View all Source files

Directories

Path Synopsis
conntest
feature
msgtest
servertest
testutil
testutil/helpers
Package private and all packages underneath it are not for public use.
 Package private and all packages underneath it are not for public use.
auth
Package auth is not for public use.
 Package auth is not for public use.
cluster
Package cluster is not for public use.
 Package cluster is not for public use.
conn
Package conn is not for public use.
 Package conn is not for public use.
examples/cluster_monitoring
examples/count
examples/server_monitoring
examples/workload
msg
Package msg is not for public use.
 Package msg is not for public use.
ops
Package ops is not for public use.
 Package ops is not for public use.
options
server
Package server is not for public use.
 Package server is not for public use.

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