SQL

coalesce sql

Return the first non-null value in a list:

SELECT COALESCE(NULL, NULL, NULL, 'W3Schools.com', NULL, 'Example.com');

-- output: W3Schools.com

coalesce function in sql server

/* Return The First Non Null Value*/

SELECT Column_Name, COALESCE (Col1, Col2, Col3,...) AS Alias_Name FROM Table_Name

For Example
/*
ID First_Name Middle _Name Last_Name
1    Sam         null         null
2    null       John          null
3    null       null          smith
*/
SELECT ID,  COALESCE (First_Name, Middle_Name, Last_Name) AS Name 
FROM tblCOSTOMER
/*
Output
ID Name
1  Sam
2  John
3  smith
*/

MSSQL COALESCE

SELECT COALESCE(NULL, NULL, NULL, 'HELLO WORLD', NULL, 'Example.com');

RESULT
'Hello World' --> First value not null