Learn From - Interactive SQL


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SQL COALESCE Function


COALESCE function can be used in a similar manner to the ISNULL function.

COALESCE function replaces the NULL value in the columns to an alternative value specified.

Below is shown the "Customers" table:

FirstName LastName Address City
White Michael 22 Cleveland Av. #24 Berkeley
Hunter Sheryl NULL Salt Lake City
Smith Charlene NULL San Francisco
Jhonson Fernandis 2286 Cram Pl. #81 NULL
Robert Paul 1976 Arlington Pl. NULL

SQL COALESCE Function Example


Type or Copy the SQL into the Text Editor, click the "View Result" button, to see the result.

In the below SQL the COALESCE function replaces the NULL value in the Address columns with "NO DATA".

Select FirstName, LastName, COALESCE(Address,'NO DATA') as Address1
from Authors;

In the below SQL the COALESCE function replaces the NULL value in the City column with "NO DATA".

Select FirstName, LastName, COALESCE(City,'NO DATA') as City1
from Authors;

SQL in Text Editor:








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