SQL: ALTER TABLE STATEMENT
This SQL tutorial explains how to use the SQL ALTER TABLE statement to add a column, modify a column, drop a column, rename a column or rename a table (with lots of clear, concise examples). We've also added some practice exercises that you can try for yourself. DESCRIPTION The SQL ALTER TABLE statement is used to add, modify, or drop/delete columns in a table. The SQL ALTER TABLE statement is also used to rename a table. ADD COLUMN IN TABLE Syntax To add a column in a table, the SQL ALTER TABLE syntax is: ALTER TABLE table_name ADD column_name column-definition; Example Let's look at a SQL ALTER TABLE example that adds a column. For example: ALTER TABLE supplier ADD supplier_name varchar2(50); This SQL ALTER TABLE example will add a column called supplier_name to the supplier table. ADD MULTIPLE COLUMNS IN TABLE Syntax To add multiple columns to an existing table, the SQL ALTER TABLE syntax is: ALTER TABLE table_name ADD (column_1 c...
