DBMS

See records with NULL

In MySQL, NULL values excluded automatically while we querying data. So to see values with all NULL values, we have to add more condition to oringal query statement. # Write your MySQL query statement below SELECT name FROM customer WHERE referee_id 2 OR referee_id IS NULL; https://www.w3schools.com/mysql/mysql_where.asp MySQL WHERE Clause W3Schools offers free online tutorials, references and e..

[Statement] DELETE

1. Syntax The DELETE statement is used to delete existing records in a table. DELETE FROM table_name WHERE condition; 2. Example DELETE FROM table WHERE table 2; 3. Error : You can't specify target table When we use subquery in DELETE statement, there is error called : you can't specify target table. The reason why this error raised is because of feature of MySQL which can't use same table for u..