SQL Alter Table

The ALTER TABLE statement is used to add, modify or delete columns in an existing table. It is also used to rename a table.

SQL ALTER TABLE Add Column

If you want to add columns in SQL table, the SQL alter table syntax is given below:

ALTER TABLE table_name ADD column_name column-definition;

If you want to add multiple columns in table, the SQL table will be




				ALTER TABLE table_name    

ADD (column_1 column-definition,   

           column_2 column-definition,   

           .....   

           column_n column-definition);  

				

SQL ALTER TABLE Modify Column

If you want to modify an existing column in SQL table, syntax is given below:

ALTER TABLE table_name MODIFY column_name column_type;

code


				ALTER TABLE table_name    

MODIFY (column_1 column_type,   

                  column_2 column_type,   

                 .....   

                  column_n column_type);

				

				

SQL ALTER TABLE DROP Column

The syntax of alter table drop column is given below:

ALTER TABLE table_name DROP COLUMN column_name;

SQL ALTER TABLE RENAME Column

The syntax of alter table rename column is given below:

  1. ALTER TABLE table_name
  2. RENAME COLUMN old_name to new_name;