In the mapping, when you specify an SQL override and the object type used is a custom query, ensure that the table you specified in the custom query and the SQL override contains the same metadata. The custom query and SQL override must be fully qualified. For example,

Select * from DB1.Schema.Table1

When the mapping contains an SQL override and custom query combination, do not specify the database or schema in the advanced source properties in the mapping and in the Additional JDBC URL Parameters field in the Snowflake connection If you do, the mapping fails.

When you configure a partially parameterized custom query, specify the default value for the parameters. For example, when you specify

Select * from $$DB1.$$Schema.$$Table1

, add a placeholder value as the default value while creating the in-out parameters for DB1, Schema1, and Table1.

If you have selected parameter as the source type in the mapping, do not select the

Allow parameter to be overridden at runtime

option. You can then select the custom query in the mapping task.

For more information about the supported overrides in combination with an SQL override from the advanced properties, see Overriding SQL.