ORA-00979 not a group by expression

Question

I am getting ORA-00979 with the following query:

SELECT cr.review_sk, cr.cs_sk, cr.full_name,
tolist(to_char(cf.fact_date, \'mm/dd/yyyy\')) \"appt\",
cs.cs_i         


        

Answer 1

You must put all columns of the SELECT in the GROUP BY or use functions on them which compress the results to a single value (like MIN, MAX or SUM).

A simple example to understand why this happens: Imagine you have a database like this:

FOO BAR
0   A
0   B

and you run SELECT * FROM table GROUP BY foo. This means the database must return a single row as result with the first column 0 to fulfill the GROUP BY but there are now two values of bar to chose from. Which result would you expect - A or B? Or should the database return more than one row, violating the contract of GROUP BY?

Answer 2

You should do the following:

SELECT cr.review_sk, 
       cr.cs_sk, 
       cr.full_name,
       tolist(to_char(cf.fact_date, 'mm/dd/yyyy')) "appt",
       cs.cs_id, 
       cr.tracking_number
from review cr, cs, fact cf
where cr.cs_sk = cs.cs_sk
       and UPPER(cs.cs_id) like '%' || UPPER(i_cs_id) || '%'
       and row_delete_date_time is null
       and cr.review_sk = cf.review_wk (+)
       and cr.fact_type_code (+) = 183050
GROUP BY cr.review_sk, cr.cs_sk, cf.fact_date, cr.tracking_number, cs.cs_id, cr.full_name
ORDER BY cs.cs_id, cr.full_name;

Answer 3

Include in the GROUP BY clause all SELECT expressions that are not group function arguments.

Answer 4

Too bad Oracle has limitations like these. Sure, the result for a column not in the GROUP BY would be random, but sometimes you want that. Silly Oracle, you can do this in MySQL/MSSQL.

BUT there is a work around for Oracle:

While the following line does not work

SELECT unique_id_col, COUNT(1) AS cnt FROM yourTable GROUP BY col_A;

You can trick Oracle with some 0's like the following, to keep your column in scope, but not group by it (assuming these are numbers, otherwise use CONCAT)

SELECT MAX(unique_id_col) AS unique_id_col, COUNT(1) AS cnt 
FROM yourTable GROUP BY col_A, (unique_id_col*0 + col_A);

Answer 5

In addition to the other answers, this error can result if there's an inconsistency in an order by clause. For instance:

select 
    substr(year_month, 1, 4)
    ,count(*) as tot
from
    schema.tbl
group by
    substr(year_month, 1, 4)
order by
    year_month

Answer 6

Same error also come when UPPER or LOWER keyword not used in both place in select expression and group by expression .

Wrong :-

select a , count(*) from my_table group by UPPER(a) .

Right :-

select UPPER(a) , count(*) from my_table group by UPPER(a) .