Filter dates from a table with DATE and NULL records in MySQL

Let us first create a table −

mysql> create table DemoTable
(
   FirstDate datetime,
   SecondDate datetime
);
Query OK, 0 rows affected (0.57 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('2019-01-21','2018-01-21');
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable values('2019-10-04','2019-08-14');
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable values('2019-05-01','2019-09-11');
Query OK, 1 row affected (0.65 sec)
mysql> insert into DemoTable values(NULL,NULL);
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable values('2019-03-01',NULL);
Query OK, 1 row affected (0.13 sec)

Display all records from the table using select statement −

Display all records from the table using select statement:

This will produce the following output −

+---------------------+---------------------+
| FirstDate           | SecondDate          |
+---------------------+---------------------+
| 2019-01-21 00:00:00 | 2018-01-21 00:00:00 |
| 2019-10-04 00:00:00 | 2019-08-14 00:00:00 |
| 2019-05-01 00:00:00 | 2019-09-11 00:00:00 |
| NULL                | NULL                |
| 2019-03-01 00:00:00 | NULL                |
+---------------------+---------------------+
5 rows in set (0.00 sec)

Following is the query to filter dates from a table with DATE and NULL records −

mysql> select *from DemoTable
where FirstDate <= curdate() and (SecondDate >=curdate() or SecondDate IS NULL);

This will produce the following output −

+---------------------+---------------------+
| FirstDate           | SecondDate          |
+---------------------+---------------------+
| 2019-05-01 00:00:00 | 2019-09-11 00:00:00 |
| 2019-03-01 00:00:00 | NULL                |
+---------------------+---------------------+
2 rows in set (0.00 sec)