QUERY: CREATE TABLE CASE_TBL (
  i integer,
  f double precision
);
QUERY: CREATE TABLE CASE2_TBL (
  i integer,
  j integer
);
QUERY: INSERT INTO CASE_TBL VALUES (1, 10.1);
QUERY: INSERT INTO CASE_TBL VALUES (2, 20.2);
QUERY: INSERT INTO CASE_TBL VALUES (3, -30.3);
QUERY: INSERT INTO CASE_TBL VALUES (4, NULL);
QUERY: INSERT INTO CASE2_TBL VALUES (1, -1);
QUERY: INSERT INTO CASE2_TBL VALUES (2, -2);
QUERY: INSERT INTO CASE2_TBL VALUES (3, -3);
QUERY: INSERT INTO CASE2_TBL VALUES (2, -4);
QUERY: INSERT INTO CASE2_TBL VALUES (1, NULL);
QUERY: INSERT INTO CASE2_TBL VALUES (NULL, -6);
QUERY: SELECT '3' AS "One",
  CASE
    WHEN 1 < 2 THEN 3
  END AS "Simple WHEN";
One|Simple WHEN
---+-----------
  3|          3
(1 row)

QUERY: SELECT '<NULL>' AS "One",
  CASE
    WHEN 1 > 2 THEN 3
  END AS "Simple default";
One   |Simple default
------+--------------
<NULL>|              
(1 row)

QUERY: SELECT '3' AS "One",
  CASE
    WHEN 1 < 2 THEN 3
    ELSE 4
  END AS "Simple ELSE";
One|Simple ELSE
---+-----------
  3|          3
(1 row)

QUERY: SELECT '4' AS "One",
  CASE
    WHEN 1 > 2 THEN 3
    ELSE 4
  END AS "ELSE default";
One|ELSE default
---+------------
  4|           4
(1 row)

QUERY: SELECT '6' AS "One",
  CASE
    WHEN 1 > 2 THEN 3
    WHEN 4 < 5 THEN 6
    ELSE 7
  END AS "Two WHEN with default";
One|Two WHEN with default
---+---------------------
  6|                    6
(1 row)

QUERY: SELECT '' AS "Five",
  CASE
    WHEN i >= 0 THEN i
  END AS ">= 0 or Null"
  FROM CASE_TBL;
Five|>= 0 or Null
----+------------
    |           1
    |           2
    |           3
    |           4
(4 rows)

QUERY: SELECT '' AS "Five",
  CASE WHEN i >= 0 THEN (i - i)
       ELSE i
  END AS "Simplest Math"
  FROM CASE_TBL;
Five|Simplest Math
----+-------------
    |            0
    |            0
    |            0
    |            0
(4 rows)

QUERY: SELECT '' AS "Five", i AS "Value",
  CASE WHEN (i < 0) THEN 'small'
       WHEN (i = 0) THEN 'zero'
       WHEN (i = 1) THEN 'one'
       WHEN (i = 2) THEN 'two'
       ELSE 'big'
  END AS "Category"
  FROM CASE_TBL;
Five|Value|Category
----+-----+--------
    |    1|one     
    |    2|two     
    |    3|big     
    |    4|big     
(4 rows)

QUERY: /*
SELECT '' AS "Five",
  CASE WHEN ((i < 0) or (i < 0)) THEN 'small'
       WHEN ((i = 0) or (i = 0)) THEN 'zero'
       WHEN ((i = 1) or (i = 1)) THEN 'one'
       WHEN ((i = 2) or (i = 2)) THEN 'two'
       ELSE 'big'
  END AS "Category"
  FROM CASE_TBL;
*/
SELECT * FROM CASE_TBL WHERE COALESCE(f,i) = 4;
i|f
-+-
4| 
(1 row)

QUERY: SELECT * FROM CASE_TBL WHERE NULLIF(f,i) = 2;
i|f
-+-
(0 rows)

QUERY: /*
This crashes the backend at the moment...
- thomas 1998-12-12
SELECT COALESCE(a.i, a.f, b.i, b.j)
  FROM CASE_TBL a, CASE2_TBL b;
*/
SELECT *
  FROM CASE_TBL a, CASE2_TBL b
  WHERE COALESCE(a.i, a.f, b.i, b.j) = 4;
i|f|i| j
-+-+-+--
4| |1|-1
4| |2|-2
4| |3|-3
4| |2|-4
4| |1|  
4| | |-6
(6 rows)

QUERY: /*
This crashes the backend at the moment...
- thomas 1998-12-12
SELECT '' AS Five, NULLIF(a.i,b.i) AS "NULLIF(a.i,b.i)",
  NULLIF(b.i, 4) AS "NULLIF(b.i,4)"
  FROM CASE_TBL a, CASE2_TBL b;
*/
SELECT '' AS "Two", *
  FROM CASE_TBL a, CASE2_TBL b
  WHERE COALESCE(f,b.i) = 2;
Two|i|f|i| j
---+-+-+-+--
   |4| |2|-2
   |4| |2|-4
(2 rows)

QUERY: UPDATE CASE_TBL
  SET i = CASE WHEN i >= 0 THEN (- i)
                ELSE (2 * i) END;
QUERY: SELECT * FROM CASE_TBL;
 i|    f
--+-----
-1| 10.1
-2| 20.2
-3|-30.3
-4|     
(4 rows)

QUERY: UPDATE CASE_TBL
  SET i = CASE WHEN i >= 2 THEN (2 * i)
                ELSE (3 * i) END;
QUERY: SELECT * FROM CASE_TBL;
  i|    f
---+-----
 -3| 10.1
 -6| 20.2
 -9|-30.3
-12|     
(4 rows)

QUERY: /*
This crashes the backend at the moment...
- thomas 1998-12-12
UPDATE CASE_TBL
  SET i = CASE WHEN b.i >= 2 THEN (2 * j)
                ELSE (3 * j) END
  FROM CASE2_TBL b
  WHERE j = -CASE_TBL.i;
SELECT * FROM CASE_TBL;
*/
DROP TABLE CASE_TBL;
QUERY: DROP TABLE CASE2_TBL;