Mega Code Archive
Non-ISO results from the CONCAT( ) operation can be converted into ISO format three different ways as follows
<![CDATA[
mysql>
mysql> CREATE TABLE date_val
-> (
-> d DATE
-> );
Query OK, 0 rows affected (0.01 sec)
mysql>
mysql> INSERT INTO date_val (d) VALUES('1864-02-28');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO date_val (d) VALUES('1900-01-15');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO date_val (d) VALUES('1987-03-05');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO date_val (d) VALUES('1999-12-31');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO date_val (d) VALUES('2000-06-04');
Query OK, 1 row affected (0.00 sec)
mysql>
mysql>
mysql> SELECT d,
-> CONCAT(YEAR(d),'-',MONTH(d),'-01') AS 'non-ISO',
-> DATE_ADD(CONCAT(YEAR(d),'-',MONTH(d),'-01'),INTERVAL 0 DAY) AS method1,
-> CONCAT(YEAR(d),'-',MONTH(d),'-01') + INTERVAL 0 DAY AS method2,
-> FROM_DAYS(TO_DAYS(CONCAT(YEAR(d),'-',MONTH(d),'-01'))) AS method3
-> FROM date_val;
+------------+------------+------------+------------+------------+
| d | non-ISO | method1 | method2 | method3 |
+------------+------------+------------+------------+------------+
| 1864-02-28 | 1864-2-01 | 1864-02-01 | 1864-02-01 | 1864-02-01 |
| 1900-01-15 | 1900-1-01 | 1900-01-01 | 1900-01-01 | 1900-01-01 |
| 1987-03-05 | 1987-3-01 | 1987-03-01 | 1987-03-01 | 1987-03-01 |
| 1999-12-31 | 1999-12-01 | 1999-12-01 | 1999-12-01 | 1999-12-01 |
| 2000-06-04 | 2000-6-01 | 2000-06-01 | 2000-06-01 | 2000-06-01 |
+------------+------------+------------+------------+------------+
5 rows in set (0.00 sec)
mysql>
mysql> drop table date_val;
Query OK, 0 rows affected (0.00 sec)
]]>