How to delete all rows except some in MySQL?

You can use NOT IN operator for the rows you do not want to delete. Following is the syntax −

delete from yourTableName where yourColumnName NOT
IN(‘yourValue1’,‘yourValue2’,‘yourValue3’,.........N);

Let us first create a table −

mysql> create table deleteAllRowsWithCondition
   -> (
   -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> Name varchar(20)
   -> );
Query OK, 0 rows affected (0.84 sec)

Following is the query to insert some records in the table using insert command −

mysql> insert into deleteAllRowsWithCondition(Name) values('Larry');
Query OK, 1 row affected (0.14 sec)

mysql> insert into deleteAllRowsWithCondition(Name) values('John');
Query OK, 1 row affected (0.21 sec)

mysql> insert into deleteAllRowsWithCondition(Name) values('Sam');
Query OK, 1 row affected (0.12 sec)

mysql> insert into deleteAllRowsWithCondition(Name) values('Mike');
Query OK, 1 row affected (0.16 sec)

mysql> insert into deleteAllRowsWithCondition(Name) values('Carol');
Query OK, 1 row affected (0.14 sec)

mysql> insert into deleteAllRowsWithCondition(Name) values('Bob');
Query OK, 1 row affected (0.06 sec)

mysql> insert into deleteAllRowsWithCondition(Name) values('David');
Query OK, 1 row affected (0.14 sec)

Following is the query to display all records from the table using select statement −

mysql> select * from deleteAllRowsWithCondition;

This will produce the following output −

+----+-------+
| Id | Name  |
+----+-------+
| 1  | Larry |
| 2  | John  |
| 3  | Sam   |
| 4  | Mike  |
| 5  | Carol |
| 6  | Bob   |
| 7  | David |
+----+-------+
7 rows in set (0.00 sec)

Here is the query to delete all rows with some condition. We are not deleting 'John','Mike',and 'Carol' here −

mysql> delete from deleteAllRowsWithCondition where Name NOT IN('John','Mike','Carol');
Query OK, 4 rows affected (0.15 sec)

Let us check whether some rows have been deleted from the table or not. Following is the query −

mysql> select * from deleteAllRowsWithCondition;

This will produce the following output −

+----+-------+
| Id | Name  |
+----+-------+
| 2  | John  |
| 4  | Mike  |
| 5  | Carol |
+----+-------+
3 rows in set (0.00 sec)