Method parseSources

rel/parse_sql.go:1158–1227

(req *SqlSelect)

}

func (m *Sqlbridge) parseSources(req *SqlSelect) error {

	discardComments(m)

	if m.Cur().T != lex.TokenFrom {
		return m.ErrMsg("expected From")
	}

	m.Next() // consume From

	if m.Cur().T == lex.TokenIdentity {
		if err := m.parseSourceTable(req); err != nil {
			return err
		}
	}

	for {

		discardComments(m)

		src := &SqlSource{}
		//u.Debugf("parseSources %v", m.Cur())
		switch m.Cur().T {
		case lex.TokenRightParenthesis:
			return nil
		case lex.TokenLeftParenthesis:
			// SELECT [columns] FROM [table] AS t1
			//   INNER JOIN (select a,b,c from users WHERE d is not null) u ON u.user_id = t1.user_id
			if err := m.parseSourceSubQuery(src); err != nil {
				return err
			}
			if m.Cur().T == lex.TokenRightParenthesis {
				m.Next()
			}
		case lex.TokenLeft, lex.TokenRight, lex.TokenInner, lex.TokenOuter, lex.TokenJoin:
			// JOIN
			if err := m.parseSourceJoin(src); err != nil {
				return err
			}
		case lex.TokenEOF, lex.TokenEOS, lex.TokenWhere, lex.TokenGroupBy, lex.TokenLimit,
			lex.TokenOffset, lex.TokenWith, lex.TokenAlias, lex.TokenOrderBy:
			return nil
		default:
			return m.ErrMsg("unexpected token")
		}

		discardComments(m)

		switch m.Cur().T {
		case lex.TokenAs:
			m.Next() // Skip over As, we don't need it
			src.Alias = m.Cur().V
			m.Next()
			// select u.name, order.date FROM user AS u INNER JOIN ....
		case lex.TokenIdentity:
			src.Alias = m.Cur().V
			m.Next()
		}