MySQL - Running MySQL in ANSI Mode

If you start mysqld with the --ansi option, the following behavior of MySQL changes:

|| is string concatenation instead of OR.

You can have any number of spaces between a function name and the `('. This forces all function names to be treated as reserved words.

`"' will be an identifier quote character (like the MySQL ``' quote character) and not a string quote character. REAL will be a synonym for FLOAT instead of a synonym of DOUBLE.

5.3 MySQL Differences Compared to ANSI SQL92

We try to make MySQL follow the ANSI SQL standard and the ODBC SQL standard, but in some cases MySQL does some things differently:

-- is only a comment if followed by a white space.

For VARCHAR columns, trailing spaces are removed when the value is stored.

In some cases, CHAR columns are silently changed to VARCHAR columns.

Privileges for a table are not automatically revoked when you delete a table. You must explicitly issue a REVOKE to revoke privileges for a table.

NULL AND FALSE will evaluate to NULL and not to FALSE. This is because we don't think it's good to have to evaluate a lot of extra conditions in this case.