I have a table in Mysql DB like following
mysql> describe APPTBL;
+-------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+----------------+
| APP_ID | int(11) | NO | PRI | NULL | auto_increment |
| CREATE_DATE | date | YES | | NULL | |
| CLOSE_DATE | date | YES | | NULL | |
| ACTION | text | YES | | NULL | |
+-------------+-------------+------+-----+---------+----------------+
While Starting of App, i am inserting the app details with CREATE_DATE and when it is closing, i am updating its CLOSE_DATE. But in case if user is restarting the app, i want to update NULL in place of CLOSE_DATE column. Here is my query,
mysql> update APPTBL set CLOSE_DATE = NULL where APP_ID = 1;
Query OK, 0 rows affected (0.00 sec)
Rows matched: 1 Changed: 0 Warnings: 0
mysql> select * from APPTBL ;
+-----------+-------------+------------+------------+
| APP_ID | CREATE_DATE | CLOSE_DATE | ACTION |
+-----------+-------------+------------+------------+
| 1 | 2013-10-08 | NULL | XXXXXYYYYY |
+-----------+-------------+------------+------------+
1 row in set (0.00 sec)
But why i am not getting any result in this??
mysql> select * from APPTBL where CLOSE_DATE = NULL;
Empty set (0.00 sec)
Also, as i am writhing a java program using this where
rs = st.executeQuery("update APPTBL set CLOSE_DATE = NULL where APP_ID = 1");
if(!rs.wasNull()){
// Why it is coming here??
}
