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MySQL error code

MySQL error 3973

MySQL server error 3973 is ER_SUBQUERY_TRANSFORM_REJECTED, reported with SQLSTATE HY000.

Statement requires a transform of a subquery to a non-SET operation (like IN2EXISTS, or subquery-to-LATERAL-derived-table). This is not allowed with optimizer switch 'subquery_to_derived' on.
Error3973
NameER_SUBQUERY_TRANSFORM_REJECTED
SQLSTATEHY000
GroupServer errors

Source: MySQL 8.4 Error Reference