SQL DROP DEFAULT

In SQL, a default is a value that is automatically assigned to a column when a new row is inserted and a value is not specified for that column. The default value is defined when the table is created or when the column is added.

The DROP DEFAULT statement in SQL allows you to remove the default value for a column. This is useful if you no longer want to use the default value or if you want to change the default value to a different value.

Syntax

The syntax for the DROP DEFAULT statement in SQL is as follows:

ALTER TABLE table_name ALTER COLUMN column_name DROP DEFAULT;

• table_name: The name of the table that contains the column you want to remove the default value from.
• column_name: The name of the column you want to remove the default value from.

Example

Suppose you have a users table with columns id, name, and email. The email column has a default value of 'example@example.com'. To remove the default value for the email column, you can use the following SQL statement:

ALTER TABLE users ALTER COLUMN email DROP DEFAULT;

After executing this statement, the email column will no longer have a default value assigned to it.

Conclusion

The DROP DEFAULT statement in SQL allows you to remove the default value for a column. This is useful if you want to change the default value for a column or if you no longer want to use a default value.