To assign value 1 while altering, use the MySQL DEFAULT. This will itself enter 1 if nothing is inserted in the same column while using the INSERT command.
Let us first create a table −
mysql> create table DemoTable ( isAdult int ); Query OK, 0 rows affected (1.39 sec)
Following is how you can assign value 1 default to the already created column −
mysql> alter table DemoTable CHANGE isAdult isAdult BOOLEAN DEFAULT '1' NOT NULL; Query OK, 0 rows affected (1.18 sec) Records: 0 Duplicates: 0 Warnings: 0
Insert some records in the table using insert command −
mysql> insert into DemoTable values(); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(0); Query OK, 1 row affected (0.15 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable;
This will produce the following output −
+---------+ | isAdult | +---------+ | 1 | | 1 | | 0 | +---------+ 3 rows in set (0.00 sec)