InterSystems IRIS TSQL Code 104 ORDER BY items must appear in the select

In this post, you’ll learn about the SQL error code 104 in InterSystems IRIS database the reason why you are receiving the TSQL message when using the InterSystems IRIS data platform

Error Code :

104

Reason for the Error code 104 in InterSystems IRIS DBMS

ORDER BY items must appear in the select list if the statement contains a UNION operator.