SQL DEFAULT Constraint on ALTER TABLE

 ALTER TABLE Persons

ADD CONSTRAINT dfCity
DEFAULT 'Sangli' FOR City;

Adding a column name and value in sql select command

 select name,rollno, class, 'No' as vacationing from stutable;

Adding Datatble column at specific Index in C#

  DataColumn Col = dt.Columns.Add("ColName", System.Type.GetType("System.Boolean"));

                Col.SetOrdinal(0);// to put the column in position 0;