Method parseAlterTableClearClause

parser/parser_alter.go:539–600

Syntax: ALTER TABLE CLEAR COLUMN|INDEX|PROJECTION (IF EXISTS)? nestedIdentifier (IN partitionClause)?

(pos Pos)

// Syntax: ALTER TABLE CLEAR COLUMN|INDEX|PROJECTION (IF EXISTS)? nestedIdentifier (IN partitionClause)?
func (p *Parser) parseAlterTableClearClause(pos Pos) (AlterTableClause, error) {
	var kind string
	switch {
	case p.matchKeyword(KeywordColumn):
		kind = KeywordColumn
	case p.matchKeyword(KeywordIndex):
		kind = KeywordIndex
	case p.matchKeyword(KeywordProjection):
		kind = KeywordProjection
	default:
		return nil, fmt.Errorf("expected keyword: COLUMN|INDEX|PROJECTION, but got %q", p.lastTokenKind())
	}
	_ = p.lexer.consumeToken()

	ifExists, err := p.tryParseIfExists()
	if err != nil {
		return nil, err
	}

	name, err := p.ParseNestedIdentifier(p.Pos())
	if err != nil {
		return nil, err
	}
	statementEnd := name.End()

	var partition *PartitionClause
	if p.tryConsumeKeywords(KeywordIn) {
		partition, err = p.tryParsePartitionClause(p.Pos())
		if err != nil {
			return nil, err
		}
		if partition != nil {
			statementEnd = partition.End()
		}
	}

	if kind == KeywordProjection {
		return &AlterTableClearProjection{
			ClearPos:       pos,
			StatementEnd:   statementEnd,
			IfExists:       ifExists,
			ProjectionName: name,
			PartitionExpr:  partition,
		}, nil
	} else if kind == KeywordColumn {
		return &AlterTableClearColumn{
			ClearPos:      pos,
			StatementEnd:  statementEnd,
			IfExists:      ifExists,
			ColumnName:    name,
			PartitionExpr: partition,
		}, nil
	} else {
		return &AlterTableClearIndex{
			ClearPos:      pos,
			StatementEnd:  statementEnd,
			IfExists:      ifExists,
			IndexName:     name,