What is the equivalent of EXCEPT in MySQL?

You cannot use EXCEPT in MySQL, instead use the NOT IN operator. Let us first create a table −

mysql> create table DemoTable
   (
   Number1 int
   );
Query OK, 0 rows affected (0.71 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values(100);
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable values(200);
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable values(300);
Query OK, 1 row affected (0.13 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable;

This will produce the following output −

+---------+
| Number1 |
+---------+
| 100     |
| 200     |
| 300     |
+---------+
3 rows in set (0.00 sec)

Following is the query to create second table −

mysql> create table DemoTable2
   (
   Number1 int
   );
Query OK, 0 rows affected (0.52 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable2 values(100);
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable2 values(400);
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable2 values(300);
Query OK, 1 row affected (0.11 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable2;

This will produce the following output −

+---------+
| Number1 |
+---------+
| 100     |
| 400     |
| 300     |
+---------+
3 rows in set (0.00 sec)

Following is the query to use NOT IN operator in place of EXCEPT −

mysql> select Number1 from DemoTable
where Number1 not in (SELECT Number1 FROM DemoTable2);

This will produce the following output −

+---------+
| Number1 |
+---------+
| 200     |
+---------+
1 row in set (0.04 sec)