Function nodeAlterTableCmds

server/ast/alter_table.go:94–186

nodeAlterTableCmds converts tree.AlterTableCmds into a slice of vitess.DDL instances that can be executed by GMS. |tableName| identifies the table being altered, and |ifExists| indicates whether the IF EXISTS clause was specified. A second slice of unsupported but safely ignored statements is return

(
	ctx *Context,
	node tree.AlterTableCmds,
	tableName vitess.TableName,
	ifExists bool)

// |tableName| identifies the table being altered, and |ifExists| indicates whether the IF EXISTS clause was specified.
// A second slice of unsupported but safely ignored statements is return as well.
func nodeAlterTableCmds(
	ctx *Context,
	node tree.AlterTableCmds,
	tableName vitess.TableName,
	ifExists bool) ([]*vitess.DDL, []string, error) {

	if len(node) == 0 {
		return nil, nil, errors.Errorf("no commands specified for ALTER TABLE statement")
	}

	vitessDdlCmds := make([]*vitess.DDL, 0, len(node))
	var unsupportedWarnings []string
	for _, cmd := range node {
		var err error
		var statement *vitess.DDL
		switch cmd := cmd.(type) {
		case *tree.AlterTableAddConstraint:
			statement, err = nodeAlterTableAddConstraint(ctx, cmd, tableName, ifExists)
			if err != nil {
				return nil, nil, err
			}
			vitessDdlCmds = append(vitessDdlCmds, statement)
		case *tree.AlterTableAddColumn:
			statement, err = nodeAlterTableAddColumn(ctx, cmd, tableName, ifExists)
			if err != nil {
				return nil, nil, err
			}
			vitessDdlCmds = append(vitessDdlCmds, statement)

			// If inline constraints have been specified, set the ConstraintAction so that they get processed
			if len(statement.TableSpec.Constraints) > 0 {
				statement.ConstraintAction = vitess.AddStr
			}

		case *tree.AlterTableDropColumn:
			statement, err = nodeAlterTableDropColumn(ctx, cmd, tableName, ifExists)
			if err != nil {
				return nil, nil, err
			}
			vitessDdlCmds = append(vitessDdlCmds, statement)
		case *tree.AlterTableDropConstraint:
			statement, err = nodeAlterTableDropConstraint(ctx, cmd, tableName, ifExists)
			if err != nil {
				return nil, nil, err
			}
			vitessDdlCmds = append(vitessDdlCmds, statement)
		case *tree.AlterTableRenameColumn:
			statement, err = nodeAlterTableRenameColumn(ctx, cmd, tableName, ifExists)
			if err != nil {
				return nil, nil, err
			}
			vitessDdlCmds = append(vitessDdlCmds, statement)
		case *tree.AlterTableSetDefault:
			statement, err = nodeAlterTableSetDefault(ctx, cmd, tableName, ifExists)
			if err != nil {
				return nil, nil, err
			}
			vitessDdlCmds = append(vitessDdlCmds, statement)