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Datetime behavior in MariaDB vs MySQL

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Hi,

I have a MariaDB db and MySQL db. My question is why do I see the following different datetime behavior between the two? One returns a record with a zero date, the other only returns a warning. Is this due to a setting I'm overlooking or is it simply due to an intrinsic behavior difference between the two?

Thanks

MariaDB Server version:      10.1.29-MariaDB MariaDB Server
MySQL Server version:         5.6.27 MySQL Community Server (GPL)

------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------

I have the following table in both: 

CREATE table TYPEMISC (a FLOAT, b DATETIME, c TIME, d VARCHAR(10));
insert into TYPEMISC values ( 111.222, '23Apr75',    '05May99' , 'a');

------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------

The same query gives two different responses:

MySQL: 

mysql> select * from TYPEMISC where b='31Jan1999';
Empty set, 2 warnings (0.00 sec)
mysql> show warning;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'warning' at line 1

MariaDB:

MariaDB > select * from TYPEMISC where b='31Jan1999';
+---------+---------------------+----------+------+
| a       | b                   | c        | d    |
+---------+---------------------+----------+------+
| 111.222 | 0000-00-00 00:00:00 | 00:00:05 | a    |
+---------+---------------------+----------+------+
1 row in set, 1 warning (0.00 sec)

MariaDB > show warning;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'warning' at line 1

------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------

They both have the same SQL Modes:

MariaDB> SELECT @@GLOBAL.sql_mode global, @@SESSION.sql_mode session;
+-------------------------------------------------------------+-------------------------------------------------------------+
| global                                                      | session                                                     |
+-------------------------------------------------------------+-------------------------------------------------------------+
| REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ANSI | REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ANSI |
+-------------------------------------------------------------+-------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT @@GLOBAL.sql_mode global, @@SESSION.sql_mode session;
+-------------------------------------------------------------+-------------------------------------------------------------+
| global                                                      | session                                                     |
+-------------------------------------------------------------+-------------------------------------------------------------+
| REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ANSI | REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ANSI |
+-------------------------------------------------------------+-------------------------------------------------------------+
1 row in set (0.00 sec)

Answer

MariaDB considers all badly formatted strings as '0000-00-00 00:00:00' for comparison purposes. Current versions of MySQL are inconsistent, in that they handle constants one way, and non-constants another way.

Consider the following example from MySQL, with confusing results:

SET sql_mode='';
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (a FLOAT, b DATETIME, c TIME, d VARCHAR(10));
INSERT INTO t1 VALUES ( 111.222, '23Apr75', '05May99', 'a');
SELECT * FROM t1 WHERE b='31Jan1999';
SELECT * FROM t1 WHERE b=IF(RAND(),'31Jan1999','31Jan1999');

SELECT * FROM t1 WHERE b='31Jan1999';
Empty set, 2 warnings (0.00 sec)

SELECT * FROM t1 WHERE b=IF(RAND(),'31Jan1999','31Jan1999');
+---------+---------------------+----------+------+
| a       | b                   | c        | d    |
+---------+---------------------+----------+------+
| 111.222 | 0000-00-00 00:00:00 | 00:00:05 | a    |
+---------+---------------------+----------+------+
1 row in set, 1 warning (0.00 sec)

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