Using COALESCE in oracle and getting ORA-00907: missing right parenthesis - sql

Question

I am trying to use COALESCE function in query but it throws an error ORA-00907: missing right parenthesis but the same query is running well in mysql i dont know how to write same query in orcale please help me out from this error.
SELECT DISTINCT sut.SERVICE_USER_TYPE , COUNT(er.ENFORCMENT_ID)
, SUM(er.FINE_AMOUNT),
COALESCE(er.CHECK_DATE>=('12-JAN-15'), er.CHECK_DATE<=('12-JAN-15''11.59.59.465000000 PM'))
from SERVICE_USER_TYPE sut
LEFT JOIN SERVICE_USERS su
ON su.SERVICE_USER_TYPE_ID = sut.SERVICE_USER_TYPE_ID
LEFT JOIN ENFORCEMENT_REPORT er ON su.SERVICE_USER_ID = er.SERVICE_USER_ID
group by sut.SERVICE_USER_TYPE ;
and the error
ORA-00907: missing right parenthesis
00907. 00000 - "missing right parenthesis"
*Cause:
*Action:
Error at Line: 4 Column: 23
please help me out..

Answer 1

You say this works in MySQL. Well, the COALESCE expression results in 0, 1 or NULL per record. Then you aggregate your rows, but there is no aggregate on your COALESCE expression. This gives you a random 0, 1 or NULL per SERVICE_USER_TYPE.
The COALESCE expression
COALESCE(er.CHECK_DATE>=('12-JAN-15'), er.CHECK_DATE<=('12-JAN-15''11.59.59.465000000 PM'))
does the following in MySQL (only obfuscated):
CASE
WHEN er.CHECK_DATE IS NULL THEN NULL
WHEN er.CHECK_DATE >= '12-JAN-15' THEN 1
WHEN er.CHECK_DATE < '12-JAN-15' THEN 0
END
or, with NULL being the default, shortly
CASE
WHEN er.CHECK_DATE >= '12-JAN-15' THEN 1
WHEN er.CHECK_DATE < '12-JAN-15' THEN 0
END
You can do the same in Oracle and any other DBMS, but think about what aggregate you want to see. (If you expect it to be the same within all records for a SERVICE_USER_TYPE, use MIN or MAX or AVG, whichever you like best.)
For instance:
MIN
(
CASE
WHEN er.CHECK_DATE >= DATE'2015-01-12' THEN 1
WHEN er.CHECK_DATE < DATE'2015-01-12' THEN 0
END
)