ZheHu created CALCITE-5771: ------------------------------ Summary: Apply two different NULL semantics for CONCAT function(enabled in MySQL、Postgresql and BigQuery) Key: CALCITE-5771 URL: https://issues.apache.org/jira/browse/CALCITE-5771 Project: Calcite Issue Type: Bug Components: core Affects Versions: 1.34.0 Reporter: ZheHu Assignee: ZheHu
We now have one CONCAT_FUNCTION which is enabled in MySQL、Postgresql、BigQuery, it always returns NULL when any of the arguments is NULL, and it accepts at least 2 arguments. The following table describes how different database products define CONCAT function: || DB Product || Argument type in CONCAT || Argument num in CONCAT || Result || |MySQL|string|at least 1|returns null if any argument is null, otherwise return string| |Postgresql|any(cast to string)|at least 1|always return string, null is treated as empty string| |BigQuery|string|at least 1|returns null if any argument is null, otherwise return string| For MySQL and BigQuery, we can reuse the current CONCAT_FUNCTION(but need to change the accepted argument number). We also need another CONCAT function for Postgresql that treats NULL as empty String. -- This message was sent by Atlassian Jira (v8.20.10#820010)