Return
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Title
Error "ORA-01791: not a SELECTed expression" when executing a SELECT DISTINCT..... ORDER BY query -
Description
Running a 'SELECT DISTINCT' query with an ORDER BY clause and getting error
"ORA-01791: not a SELECTed expression"
Here's an example of what is being run
SELECT DISTINCT
EMPLOYEE_ID,
substr(employees.FIRST_NAME,1,3 -
Cause
Oracle limitation, not Toad issue
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Resolution
Replace ORDER BYEMPLOYEES.FIRST_NAME with column alias name or the substring expression
ORDER BY "fname" or
ORDER BY substr(employees.FIRST_NAME,1,3)