ORA-00937: not a single-group group function说明及解决方法(E文)

 A SELECT list cannot include both a group function, such as AVG, COUNT, MAX, MIN, SUM, STDDEV, or VARIANCE, and an 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 an additional column (OWNER), 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