woodpecker/pkg/database/migrate/api.go
Nurahmadie 44ffb70813 Use variadic parameters for DropColumns.
Also add some comments.
2014-03-16 12:26:18 +07:00

63 lines
2.2 KiB
Go

package migrate
import (
"database/sql"
)
// Operation interface covers basic migration operations.
// Implementation details is specific for each database,
// see migrate/sqlite.go for implementation reference.
type Operation interface {
// CreateTable may be used to create a table named `tableName`
// with its columns specification listed in `args` as an array of string
CreateTable(tableName string, args []string) (sql.Result, error)
// RenameTable simply rename table from `tableName` to `newName`
RenameTable(tableName, newName string) (sql.Result, error)
// DropTable drops table named `tableName`
DropTable(tableName string) (sql.Result, error)
// AddColumn adds single new column to `tableName`, columnSpec is
// a standard column definition (column name included) which may looks like this:
//
// mg.AddColumn("example", "email VARCHAR(255) UNIQUE")
//
// it's equivalent to:
//
// mg.AddColumn("example", mg.T.String("email", UNIQUE))
//
AddColumn(tableName, columnSpec string) (sql.Result, error)
// ChangeColumn may be used to change the type of a column
// `newType` should always specify the column's new type even
// if the type is not meant to be change. Eg.
//
// mg.ChangeColumn("example", "name", "VARCHAR(255) UNIQUE")
//
ChangeColumn(tableName, columnName, newType string) (sql.Result, error)
// DropColumns drops a list of columns
DropColumns(tableName string, columnsToDrop ...string) (sql.Result, error)
// RenameColumns will rename columns listed in `columnChanges`
RenameColumns(tableName string, columnChanges map[string]string) (sql.Result, error)
// AddIndex adds index on `tableName` indexed by `columns`
AddIndex(tableName string, columns []string, flags ...string) (sql.Result, error)
// DropIndex drops index indexed by `columns` from `tableName`
DropIndex(tableName string, columns []string) (sql.Result, error)
}
// MigrationDriver drives migration script by injecting transaction object (*sql.Tx),
// `Operation` implementation and column type helper.
type MigrationDriver struct {
Operation
T *columnType
Tx *sql.Tx
}
// DriverBuilder is a constructor for MigrationDriver
type DriverBuilder func(tx *sql.Tx) *MigrationDriver