SQL IS NOT NULL

The SQL IS NOT NULL is useful to find whether the specified expression is nullable; if it is not, then TRUE will be returned. Otherwise, it returns FALSE. It is always advisable to use IS NOT to look for NULL values. The syntax behind this is

SELECT Column_Names 
FROM Table
WHERE Expression IS NOT NULL

SQL IS NOT NULL Example

The following screenshot will show you the data inside the table.

In this example, we will use this to SELECT and return all the customer records from the [TenCustomers] table, whose Last Name is NOT Nullable value

SELECT [CustomerKey]
      ,[FirstName]
      ,[LastName]
      ,[EmailAddress]
      ,[YearlyIncome]
      ,[EnglishOccupation]
      ,[AddressLine1]
      ,[Phone]
  FROM [TenCustomers]
  WHERE [LastName] IS NOT NULL

It’s another example of the SQL Server IS NOT NULL function. Here, we are using the [Emp] table, and the data inside this table is

The following Server query returns all the employee records whose Office Phone numbers are Non-empty values.

SELECT [Id]
      ,[Name]
      ,[Education]
      ,[Occupation]
      ,[YearlyIncome]
      ,[Office Phone]
      ,[Mobile]
      ,[Home Phone]
  FROM [Emp]
  WHERE [Office Phone] IS NOT NULL

The below code Selects all the records whose Office numbers or Mobile numbers are NOT NULL values

SELECT [Id]
      ,[Name]
      ,[Education]
      ,[Occupation]
      ,[YearlyIncome]
      ,[Office Phone]
      ,[Mobile]
      ,[Home Phone]
  FROM [Emp]
  WHERE [Office Phone] IS NOT NULL OR 
	[Mobile] IS NOT NULL