Add new column sql server tsql

To add a new column to a table in SQL Server using T-SQL, you can use the ALTER TABLE statement with the ADD clause. Here is the general syntax:

ALTER TABLE table_name
ADD column_name data_type;

Here:

• table_name is the name of the table you want to modify.
• column_name is the name of the new column you want to add.
• data_type is the data type of the new column.

For example, to add a new column called NewColumn with a data type of int to a table called MyTable, you would use the following statement:

ALTER TABLE MyTable
ADD NewColumn int;

You can also specify additional options, such as:

• NULL or NOT NULL to specify whether the column can contain null values.
• DEFAULT to specify a default value for the column.
• IDENTITY to specify that the column is an identity column.

Here is an example that adds a new column called NewColumn with a data type of int, allows null values, and sets a default value of 0:

ALTER TABLE MyTable
ADD NewColumn int NULL DEFAULT 0;

You can also add a new column with a specific length or precision, for example:

ALTER TABLE MyTable
ADD NewColumn varchar(50);

This will add a new column called NewColumn with a data type of varchar and a length of 50 characters.

It's also important to note that you can add a new column to a table that already has data, but you need to specify the NULL or NOT NULL option to specify whether the column should be populated with the existing data or not.

For example, to add a new column called NewColumn with a data type of int to a table called MyTable and populate it with the existing data, you would use the following statement:

ALTER TABLE MyTable
ADD NewColumn int NULL;

This will add the new column and populate it with the existing data. If you want to add the new column and not populate it with the existing data, you would use the following statement:

ALTER TABLE MyTable
ADD NewColumn int NOT NULL;

This will add the new column, but it will not be populated with the existing data.