mysql> create table forDeletes(id int primary key, a int);
Query OK, 0 rows affected (0.02 sec)

mysql> insert into forDeletes VALUES(1,1),(2,2),(3,3),(4,4),(6,9),(100, 9);
Query OK, 6 rows affected (0.00 sec)
Records: 6  Duplicates: 0  Warnings: 0

mysql> select * from forDeletes;
+-----+------+
| id  | a    |
+-----+------+
|   1 |    1 |
|   2 |    2 |
|   3 |    3 |
|   4 |    4 |
|   6 |    9 |
| 100 |    9 |
+-----+------+
6 rows in set (0.00 sec)

mysql> delete from forDeletes
    -> where id = 2;
Query OK, 1 row affected (0.00 sec)

mysql> where id = 2;
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 'where id = 2' at line 1
mysql> select * from forDeletes;
+-----+------+
| id  | a    |
+-----+------+
|   1 |    1 |
|   3 |    3 |
|   4 |    4 |
|   6 |    9 |
| 100 |    9 |
+-----+------+
5 rows in set (0.01 sec)

mysql> delete from forDeletes 
    -> where Id < 3 OR Id > 50;
Query OK, 2 rows affected (0.00 sec)

mysql> select * from forDeletes;
+----+------+
| id | a    |
+----+------+
|  3 |    3 |
|  4 |    4 |
|  6 |    9 |
+----+------+
3 rows in set (0.00 sec)

mysql> delete from forDeletes where Id < a;
Query OK, 1 row affected (0.00 sec)

mysql> select * from forDeletes;
+----+------+
| id | a    |
+----+------+
|  3 |    3 |
|  4 |    4 |
+----+------+
2 rows in set (0.00 sec)

mysql> exit