ALTER TABLE - ALTER/MODIFY DATATYPE. To change the data type of a column in a table, use the following syntax: SQL Server / MS Access:

Mar 9, 2009 · The syntax to modify a column in an existing table in SQL Server (Transact-SQL) is: ALTER TABLE table_name ALTER COLUMN column_name column_type; For example: ALTER TABLE employees ALTER COLUMN last_name VARCHAR(75) NOT NULL;

May 18, 2012 · According to the PostgreSQL docs, you can simply alter table. ALTER TABLE products ALTER COLUMN price TYPE numeric(10,2); But here's the thing. This will succeed only if each existing entry in the column can be converted to the new type by an implicit cast.

Aug 20, 2024 · In this article, we explored how to change a column’s data type across different database management systems: MySQL, PostgreSQL, and SQL Server. Each system offers unique methods for altering column types, with PostgreSQL providing advanced features like the USING clause for type conversion.

Sep 22, 2021 · We can use ALTER TABLE ALTER COLUMN statement to change the column type of the table. The syntax to change the column type is following: In the syntax, Col_name: Specify the column name whose datatype you want to change. The col_name must be specified after the ALTER COLUMN keyword. For demonstration, I have created a table named tblStudent.

Apr 5, 2024 · In SQL, the ALTER COLUMN statement is used to modify or change the definition of an existing column in a table. It allows you to change the data type, size, nullability, default value, and other properties of a column.

Feb 10, 2025 · Learn how to change a column's data type in SQL using ALTER TABLE. Step-by-step guide with real-world examples and key considerations.

In SQL Server, the ALTER command is a powerful tool for modifying existing tables and columns in your database without needing to delete or recreate them. One of the most common uses of this command is to change the data type of a column.

Mar 13, 2025 · Using the T-SQL ALTER TABLE statement you can add new columns, delete columns, change the data type of existing columns, or create indexes or constraints. ALTER TABLE can also reassign...

The ALTER COLUMN command is used to change the data type of a column in a table. The following SQL changes the data type of the column named "BirthDate" in the "Employees" table to type year: Example