What is “SELECT TRUE” in MySQL?

The statement SELECT TRUE returns 1 if a row match. Let us first create a table −

mysql> create table DemoTable(Name varchar(100)); Query OK, 0 rows affected (0.54 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.12 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+--------+ | Name   | +--------+ | Chris  | | Robert | | David | +--------+ 3 rows in set (0.00 sec)

Following is the query for SELECT TRUE −

mysql> select true from DemoTable;

This will produce the following output −

+------+ | TRUE | +------+ | 1    | | 1    | | 1    | +------+ 3 rows in set (0.00 sec)