[CALCITE-5163] MysqlSqlDialect unparse LISTAGG aggregate function error

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.31.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Xurenhe
• Reporter: Xurenhe
• Created: 20/May/22 08:22
• Updated: 03/Aug/22 16:21
• Resolved: 27/May/22 02:01

Description

CALCITE-4349 supports GROUP_CONCAT aggregate function. The code translated GROUP_CONCAT to LISTAGG during sql_to_rel.

But, MysqlSqlDialect keep LISTAGG after uparsing query's relnode, the result sql couldn't be executed in MySQL engine.

 

I expect the following test case to be successful, but it's failed.

// test in org.apache.calcite.rel.rel2sql.RelToSqlConverterTest
@Test void testMySqlGroupConcat() {
  final String query = "select\n"
      + "listagg(distinct \"product_name\", ',') within group(order by \"cases_per_pallet\")"
      + "from \"product\"\n"
      + "group by \"product_id\"\n";
  final String expected = "SELECT GROUP_CONCAT(DISTINCT `product_name` ORDER BY "
      + "`cases_per_pallet` IS NULL, `cases_per_pallet` SEPARATOR ',')\n"
      + "FROM `foodmart`.`product`\n"
      + "GROUP BY `product_id`";
  sql(query).withMysql().ok(expected);
}

Issue Links

• Blocked: CALCITE-4349 Support GROUP_CONCAT aggregate function for MySQL
• links to: GitHub Pull Request #2812
• links to: PR