Method parse_columns

src/sql-parser/src/parser.rs:5340–5408

(
        &mut self,
        optional: IsOptional,
    )

    }

    fn parse_columns(
        &mut self,
        optional: IsOptional,
    ) -> Result<(Vec<ColumnDef<Raw>>, Vec<TableConstraint<Raw>>), ParserError> {
        let mut columns = vec![];
        let mut constraints = vec![];

        if !self.consume_token(&Token::LParen) {
            if optional == Optional {
                return Ok((columns, constraints));
            } else {
                return self.expected(
                    self.peek_pos(),
                    "a list of columns in parentheses",
                    self.peek_token(),
                );
            }
        }
        if self.consume_token(&Token::RParen) {
            // Tables with zero columns are a PostgreSQL extension.
            return Ok((columns, constraints));
        }

        loop {
            if let Some(constraint) = self.parse_optional_table_constraint()? {
                constraints.push(constraint);
            } else if let Some(column_name) = self.consume_identifier()? {
                let data_type = self.parse_data_type()?;
                let collation = if self.parse_keyword(COLLATE) {
                    Some(self.parse_item_name()?)
                } else {
                    None
                };
                let mut options = vec![];
                loop {
                    match self.peek_token() {
                        None | Some(Token::Comma) | Some(Token::RParen) => break,
                        _ => options.push(self.parse_column_option_def()?),
                    }
                }

                columns.push(ColumnDef {
                    name: column_name,
                    data_type,
                    collation,
                    options,
                });
            } else {
                return self.expected(
                    self.peek_pos(),
                    "column name or constraint definition",
                    self.peek_token(),
                );
            }
            if self.consume_token(&Token::Comma) {
                // Continue.
            } else if self.consume_token(&Token::RParen) {
                break;