driver

type Beginner interface {
	Begin() (Tx, error)
}

type Conn interface {
	Databaser
	Beginner
	Close() error
}

type Copy interface {
	CopyToWriter(w io.Writer, sql string, args ...interface{}) error
	CopyFromReader(r io.Reader, sql string, args ...interface{}) error
}

type CopyConn interface {
	Copy
	Conn
}

type Databaser interface {
	Execer
	RowQueryer
	Queryer
}

type Driver interface {
	// Creates and returns a connection
	NewConn(url, searchPath string) (conn Conn, err error)

	// SearchPath sets the search path and returns a func that reverts the change
	SearchPath(conn Conn, newSearchPath string) (revert func() error, err error)

	// Ensure the version table exists
	EnsureVersionTable(db Beginner, schema string) (err error)

	// FilenameExtension returns the extension of the migration files.
	// The returned string must not begin with a dot.
	FilenameExtension() string

	// TableName returns the table name used for storing schema migration versions.
	TableName() string

	// Migrate is the heart of the driver.
	// It will receive a file which the driver should apply
	// to its backend or whatever. The migration function should use
	// the pipe channel to return any errors or other useful information.
	Migrate(db Databaser, file *file.Migration, pipe chan interface{})

	// Version returns the current migration version.
	Version(db RowQueryer) (version file.Version, err error)

	// GetMigrationFiles gets all migration files in the schema migrations table
	GetMigrationFiles(db Databaser) (files file.MigrationFiles, err error)

	// UpdateFiles updates the up and down file contents
	UpdateFiles(db Databaser, file *file.Migration, pipe chan interface{})
}

type DumpDriver interface {
	Driver
	NewCopyConn(url, searchPath string) (conn CopyConn, err error)
	Dump(conn CopyConn, dw file.DumpWriter, schema string, pipe chan interface{}, handleInterrupts func() chan os.Signal)
	Restore(conn CopyConn, dr file.DumpReader, schema string, pipe chan interface{}, handleInterrupts func() chan os.Signal)
	DeleteSchema(db Execer, schema string) error
	TruncateTables(db Conn, schema string) error
}

type Execer interface {
	Exec(query string, args ...interface{}) error
}

type Queryer interface {
	Query(query string, args ...interface{}) (RowsScanner, error)
}

type RowQueryer interface {
	QueryRow(query string, args ...interface{}) Scanner
}

type RowsScanner interface {
	// Columns() ([]string, error)
	Scan(dest ...interface{}) (err error)
	Err() error
	Next() bool
	Close()
}

type Scanner interface {
	// Columns() ([]string, error)
	Scan(dest ...interface{}) (err error)
}

type Tx interface {
	Databaser
	Rollback() error
	Commit() error
}