Using Coalesce() in sqlserver

Introduction

When we have multi-value attribute with single or more null values in a Table, the Coalesce() function is very useful.

Using the Code

If you consider the below facts placed in a employee table with Id, Name, ph_no, Alt_no, Office no.

The above Employee table may have single value or three values. If it has single value, then it fills 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 the first encountered Not Null Value from employee table.

select id , name ,coalesce(Ph_no,Alt_no,Office_no) as contact number from employee 

It returns:

Thank you!