Parameters in TencentDB for MySQL have been optimized on the basis of official default values in MySQL. We recommend that you configure the following parameters for the TencentDB for MySQL instance after purchase based on your business scenarios.
NO_ENGINE_SUBSTITUTION (v5.6); ONLY_FULL_GROUP_BY, STRICT_TRANS_TABLES, NO_ZERO_IN_DATE, NO_ZERO_DATE, ERROR_FOR_DIVISION_BY_ZERO, NO_AUTO_CREATE_USER, NO_ENGINE_SUBSTITUTION (v5.7)
Restart required: no
Description: TencentDB for MySQL can operate in different SQL modes, which define the SQL syntax and data check that it should support.
The default value of this parameter in v5.6 is
NO_ENGINE_SUBSTITUTION, which means that if the used storage engine is disabled or not compiled, an error will be thrown; in v5.7, the default values are
ONLY_FULL_GROUP_BY, STRICT_TRANS_TABLES, NO_ZERO_IN_DATE, NO_ZERO_DATE, ERROR_FOR_DIVISION_BY_ZERO, NO_AUTO_CREATE_USER, NO_ENGINE_SUBSTITUTION.
ONLY_FULL_GROUP_BY is enabled, MySQL rejects queries for which the select list,
HAVING condition, or
ORDER BY list refer to nonaggregated columns that are neither named in the
GROUP BY clause nor are functionally dependent on
GROUP BY columns.
STRICT_TRANS_TABLES enables strict SQL mode.
NO_ZERO_IN_DATE controls whether the server permits dates in which the year part is nonzero but the month or day part is zero. The effect of
NO_ZERO_IN_DATE depends on whether strict SQL mode is enabled.
NO_ZERO_DATE controls whether the server permits a zero date as valid. Its effect depends on whether strict SQL mode is enabled.
ERROR_FOR_DIVISION_BY_ZERO means that in strict SQL mode, if data is divided by zero during the INSERT or UPDATE process, an error rather than a warning will be generated, while in non-strict SQL mode, NULL will be returned.
NO_AUTO_CREATE_USER prohibits the GRANT statement from creating a user whose password is empty.
NO_ENGINE_SUBSTITUTION means that if the storage engine is disabled or not compiled, an error will be thrown.
Recommendation: as different SQL modes support different SQL syntax, we recommend that you configure them based on your business needs and development habits.