Ora-00937:not a single-group group function description and solution (e)

 a SELECT list cannot include both a group function, such as AVG, COUNT, MAX, MIN, SUM, StdDev, or variance, and A n individual column expression, unless the individual column expression is included in a GROUP by clause.



Drop either the group function or the individual column expression from the SELECT list or add a group by Clause that includes all individual column expressions listed.


Eg:

Sql> Select owner, COUNT (*)
  2  from dba_segments;
Select owner, COUNT (*)
       *
ERROR at line 1:
Ora-00937:not a Single-group Group function

Because we have a group function (COUNT) in our column list, and a additional column (Owne R), we have to include the GROUP by clause in our SELECT statement.

sql> Select owner, COUNT (*)
  2  from dba_segments
  3  GROUP by owner;

owner                             COUNT (*)
-------------------------------- --------
user1                               166
user2                                166