web training room for online courses
Learn SQL Database Development, MS SQL Tutorial Online

Alter SQL Table Syntax Example

Here you learn alter table statement in sql server, and how to alter column in sql table.

(Note: here we are not talking about updating data in SQL table, we are talking about altering / updating SQL Table structure). The SQL Server (Transact-SQL) ALTER TABLE statement is used to add, modify, or drop columns in a table.

How to add a new column in (Alter) Existing SQL Table

Alter table statement in sql server, In case you want to add a new column in your existing SQL Table.

Alter  TABLE [tableName]            
            Add  ColumnName nvarchar(1000)

How to change a column name in (Alter) Existing SQL Table

Alter TABLE, Change column name in SQL Table, To change the name of the column in some particular table we will be built-in SQL store procedure “sp_rename” , here is an example.

sp_rename '[tableName].ColumnName', 'NewColumnName', 'COLUMN';

Note: After changing Column name in SQL Table may break your scripts and stored procedures, views, function, triggers. So, Remember to change them in all other places

How to drop a column in (Alter) Existing SQL Table
In case you want to drop a column from SQL table permanently

ALTER TABLE [tableName]            
            DROP COLUMN ColumnName;

Once you drop the column all data in that particular column will be lost permanently

How to rename a Table in SQL Server
Remember, You can not use the ALTER TABLE statement in SQL Server to Rename a SQL Table, there is a system stored procedure called "sp_rename" to do that job.

Here is the syntax to Rename a table in SQL Server.
sp_rename 'old_table_name', 'new_table_name';

Note: even after changing the table name, all constraint names like primary key, foreign key will remain the same

Name Email Website
Alter Table in SQL Database