statement to delete column in sql

In SQL, the syntax for using the ALTER TABLE statement to delete a table column is: ALTER TABLE table_name DROP COLUMN column_name. This statement permanently deletes all data in the specified column. If the column is part of a foreign key, unique constraint, or primary key, the associated constraints must also be deleted.

SQL statement to delete a column

In SQL, you can use ALTER TABLE statement to delete a column from the table. The syntax is as follows:

<code>ALTER TABLE table_name DROP COLUMN column_name;</code>

Among them:

• table_name is the name of the table where the column is to be deleted.
• column_name is the name of the column to be deleted.

Example

Suppose we have a table named customers which contains the following columns:

<code>id | name | email | phone</code>

To delete the phone column, you can use the following statement:

<code>ALTER TABLE customers DROP COLUMN phone;</code>

Note:

• After deleting a column, all data in the column All will be permanently deleted.
• If the column being deleted is a foreign key, the foreign key constraint associated with the column must also be deleted.
• If the column being dropped is part of a unique constraint or primary key, these constraints must also be dropped.

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