SQL Server built-in functions Coalesce() It is A function Is Very Much Useful at Run time When We Have Multi Value Attribute in a Table. If U Consider below facts placed in a employee table With Id, Name, ph_no, Alt_no, Office no. id Name Ph_ no Alt_ no Office no 101 Albert 999999 456453 321333 102 khan null null 123455 103 victor 112121 null null 104 lovely null null 1897321 Above Employee table may have single value are three values if it have single value then it fill null values with remaining attributes When We Retrieve The Number from employee table That Number Should Not be Null value To get not null value from employee table We Use Coalesce() Function It Returns First Encountered Not Null Value from employee table select id , name , coalesce ( Ph_no , Alt_no , Office_no ) as contact number from employee