alter table sql statement code example
Example 1: sql add column
ALTER TABLE Customers
ADD Email varchar(255);
Example 2: sql server alter column
ALTER TABLE table_name
ALTER COLUMN column_name new_data_type(size);
Example 3: sql alter table
-- With check if field already exists
IF NOT EXISTS(SELECT 1 FROM sys.columns
WHERE Name = N'Email'
AND Object_ID = Object_ID(N'dbo.Customers'))
BEGIN
ALTER TABLE Customers
ADD Email varchar(255);
END