# SQL Mode

__*SQL_MODE*__

+ The SQL mode affects the SQL syntax supported by TiDB and its behavior for data validation
  + The SQL mode is set via the sql_mode variable
+ SQL mode exist at the global level and session level
  + By default, new sessions use global SQL mode
  + All users can change the SQL mode of their own session

------------------------------------------------------------
The TiDB server uses different SQL mode to operate, and different clients can apply different modes. The SQL mode defines which SQL syntax TiDB supports and which data validation checks are performed.