forked from mirror/gorm
51 lines
1.6 KiB
Go
51 lines
1.6 KiB
Go
package gorm
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import (
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"fmt"
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"reflect"
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)
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// Dialect interface contains behaviors that differ across SQL database
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type Dialect interface {
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// BindVar return the placeholder for actual values in SQL statements, in many dbs it is "?", Postgres using $1
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BindVar(i int) string
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// Quote quotes field name to avoid SQL parsing exceptions by using a reserved word as a field name
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Quote(key string) string
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// DataTypeOf return data's sql type
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DataTypeOf(value reflect.Value, tagSettings map[string]string) string
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// HasIndex check has index or not
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HasIndex(scope *Scope, tableName string, indexName string) bool
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// RemoveIndex remove index
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RemoveIndex(scope *Scope, indexName string)
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// HasTable check has table or not
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HasTable(scope *Scope, tableName string) bool
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// HasColumn check has column or not
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HasColumn(scope *Scope, tableName string, columnName string) bool
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// LimitAndOffsetSQL return generate SQL with limit and offset, as mssql has special case
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LimitAndOffsetSQL(limit, offset int) string
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// SelectFromDummyTable return select values, for most dbs, `SELECT values` just works, mysql needs `SELECT value FROM DUAL`
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SelectFromDummyTable() string
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// LastInsertIdReturningSuffix most dbs support LastInsertId, but postgres needs to use `RETURNING`
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LastInsertIdReturningSuffix(tableName, columnName string) string
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}
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func NewDialect(driver string) Dialect {
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var d Dialect
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switch driver {
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case "postgres":
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d = &postgres{}
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case "mysql":
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d = &mysql{}
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case "sqlite3":
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d = &sqlite3{}
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case "mssql":
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d = &mssql{}
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default:
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fmt.Printf("`%v` is not officially supported, running under compatibility mode.\n", driver)
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d = &commonDialect{}
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}
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return d
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}
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