1ALTER TABLE table_name
2ADD column_name datatype;
3
4--example
5ALTER TABLE Customers
6ADD Email varchar(255);
1-- With check if field already exists
2
3IF NOT EXISTS(SELECT 1 FROM sys.columns
4 WHERE Name = N'Email'
5 AND Object_ID = Object_ID(N'dbo.Customers'))
6BEGIN
7 ALTER TABLE Customers
8 ADD Email varchar(255);
9END