dialects

Documentation

Overview

Package dialects defines a uniform interface for creating custom support for different SQL databases.

Index

• func IsQL(d Dialect) bool
• func Register(d Dialect)
• type DefaultOpener
  • func Opener() *DefaultOpener
  • func (d *DefaultOpener) FindDialect(dia string) Dialect
  • func (d *DefaultOpener) Open(dialect string, args ...interface{}) (model.SQLCommon, Dialect, error)
  • func (d *DefaultOpener) RegisterDialect(dia Dialect)
• type Dialect

Functions

func IsQL

func IsQL(d Dialect) bool

IsQL returns true if the dialect is ql

func Register

func Register(d Dialect)

Register adds the dialect to global dialects registry

Types

type DefaultOpener

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

DefaultOpener implements Opener interface.

func Opener

func Opener() *DefaultOpener

Opener returns the default Opener

func (*DefaultOpener) FindDialect

func (d *DefaultOpener) FindDialect(dia string) Dialect

FindDialect lookup for a dialect with name dia. Returns a dialect or nil in case there was no dialect found

func (*DefaultOpener) Open

func (d *DefaultOpener) Open(dialect string, args ...interface{}) (model.SQLCommon, Dialect, error)

Open opens up database connection using the database/sql package.

func (*DefaultOpener) RegisterDialect

func (d *DefaultOpener) RegisterDialect(dia Dialect)

RegisterDialect stores the dialect. This is safe to call in multiple goroutines

type Dialect

type Dialect interface {
	// GetName get dialect's name
	GetName() string

	// SetDB set db for dialect
	SetDB(db model.SQLCommon)

	// BindVar return the placeholder for actual values in SQL statements, in many dbs it is "?", Postgres using $1
	BindVar(i int) string
	// Quote quotes field name to avoid SQL parsing exceptions by using a reserved word as a field name
	Quote(key string) string

	// DataTypeOf return data's sql type
	DataTypeOf(field *model.StructField) (string, error)

	// HasIndex check has index or not
	HasIndex(tableName string, indexName string) bool
	// HasForeignKey check has foreign key or not
	HasForeignKey(tableName string, foreignKeyName string) bool
	// RemoveIndex remove index
	RemoveIndex(tableName string, indexName string) error
	// HasTable check has table or not
	HasTable(tableName string) bool
	// HasColumn check has column or not
	HasColumn(tableName string, columnName string) bool

	// LimitAndOffsetSQL return generated SQL with Limit and Offset, as mssql has special case
	LimitAndOffsetSQL(limit, offset interface{}) string
	// SelectFromDummyTable return select values, for most dbs, `SELECT values` just works, mysql needs `SELECT value FROM DUAL`
	SelectFromDummyTable() string
	// LastInsertIdReturningSuffix most dbs support LastInsertId, but postgres needs to use `RETURNING`
	LastInsertIDReturningSuffix(tableName, columnName string) string

	// BuildForeignKeyName returns a foreign key name for the given table, field and reference
	BuildForeignKeyName(tableName, field, dest string) string

	// CurrentDatabase return current database name
	CurrentDatabase() string

	// PrimaryKey returns string representation of primary keys. It is common
	// for this to return a string with keys joined to a string with comma as
	// separator
	PrimaryKey(keys []string) string

	// QueryFieldName takes a table name and returns a prefix for the field
	// name. Some databases support refering to table fields from table name,
	// for instance
	//
	// users.id
	//
	// Here users. is the prefix and id is the field name. We can go about and
	// implement something like this
	//
	// func QueryFieldName(tableName string) string {
	// 	return tableName + "."
	// }
	QueryFieldName(tableName string) string
}

Dialect interface contains behaviors that differ across SQL database