Answers for "transact sql add column"

create column sql server

ALTER TABLE table_name
ADD column_name datatype;

sql server add column

ALTER TABLE dbo.doc_exa ADD column_b VARCHAR(20) NULL, column_c INT NULL ;

T-SQL Add Column

ALTER TABLE sales.quotations 
    ADD 
        amount DECIMAL (10, 2) NOT NULL,
        customer_name VARCHAR (50) NOT NULL;
Code language: SQL (Structured Query Language) (sql)

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