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SQL ALTER TABLE Statement. The ALTER TABLE statement is used to add, delete, or modify columns in an existing table. The ALTER TABLE statement is also used to add and drop various constraints on an existing table.
In SQL, the ALTER TABLE command is used to modify the structure of an existing table like adding, deleting, renaming columns, etc. Example-- add phone column to Customers table ALTER TABLE Customers ADD phone varchar(10); Here, the SQL command adds a column named phone to the Customers table.
Summary: in this tutorial, you will learn how to use the SQL Server ALTER TABLE ALTER COLUMN statement to modify a column of a table. SQL Server allows you to perform the following changes to an existing column of a table: Modify the data type. Change the size. Add a NOT NULL constraint.
5 Απρ 2022 · ALTER TABLE [Employee] ALTER COLUMN [Salary] NUMERIC(22,5) if you use MySQL; you should try this script: ALTER TABLE [Employee] MODIFY COLUMN [Salary] NUMERIC(22,5)
Add a new column using the ADD clause. Modify attribute of a column such as constraint, default value, etc. using the MODIFY clause. Remove columns using the DROP clause. We will examine each operation in detail in the following sections. SQL ALTER TABLE ADD column.
This SQL Server tutorial explains how to use the ALTER TABLE statement in SQL Server (Transact-SQL) to add a column, modify a column, drop a column, rename a column or rename a table with syntax and examples.
19 Σεπ 2022 · Microsoft supports the SQL ALTER TABLE syntax to help the database administrator make changes to a table. Today, we will explore the three main tasks: add a column, change a column, and delete a column in this SQL Tutorial.
