insert_statement ::=
INSERT_INTO {table_reference | [THE] (subquery1)}
[(column_name [, column_name]...)]
{VALUES (sql_expression [, sql_expression]...)
| subquery2} [RETURNING]
[row_expression [, row_expression]... INTO
{variable_name | :host_variable_name}
[, {variable_name | :host_variable_name}]...];