1999-02-23 08:30:05 +01:00
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QUERY: CREATE TABLE CASE_TBL (
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i integer,
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f double precision
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);
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QUERY: CREATE TABLE CASE2_TBL (
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i integer,
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j integer
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);
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QUERY: INSERT INTO CASE_TBL VALUES (1, 10.1);
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QUERY: INSERT INTO CASE_TBL VALUES (2, 20.2);
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QUERY: INSERT INTO CASE_TBL VALUES (3, -30.3);
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QUERY: INSERT INTO CASE_TBL VALUES (4, NULL);
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QUERY: INSERT INTO CASE2_TBL VALUES (1, -1);
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QUERY: INSERT INTO CASE2_TBL VALUES (2, -2);
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QUERY: INSERT INTO CASE2_TBL VALUES (3, -3);
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QUERY: INSERT INTO CASE2_TBL VALUES (2, -4);
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QUERY: INSERT INTO CASE2_TBL VALUES (1, NULL);
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QUERY: INSERT INTO CASE2_TBL VALUES (NULL, -6);
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QUERY: SELECT '3' AS "One",
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1998-12-04 16:36:51 +01:00
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CASE
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WHEN 1 < 2 THEN 3
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1999-02-23 08:30:05 +01:00
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END AS "Simple WHEN";
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One|Simple WHEN
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---+-----------
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3| 3
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1998-12-04 16:36:51 +01:00
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(1 row)
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1999-02-23 08:30:05 +01:00
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QUERY: SELECT '<NULL>' AS "One",
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1998-12-04 16:36:51 +01:00
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CASE
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WHEN 1 > 2 THEN 3
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1999-02-23 08:30:05 +01:00
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END AS "Simple default";
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One |Simple default
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------+--------------
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<NULL>|
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1998-12-04 16:36:51 +01:00
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(1 row)
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1999-02-23 08:30:05 +01:00
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QUERY: SELECT '3' AS "One",
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1998-12-04 16:36:51 +01:00
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CASE
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WHEN 1 < 2 THEN 3
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ELSE 4
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1999-02-23 08:30:05 +01:00
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END AS "Simple ELSE";
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One|Simple ELSE
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---+-----------
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3| 3
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1998-12-04 16:36:51 +01:00
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(1 row)
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1999-02-23 08:30:05 +01:00
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QUERY: SELECT '4' AS "One",
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1998-12-04 16:36:51 +01:00
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CASE
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WHEN 1 > 2 THEN 3
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ELSE 4
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1999-02-23 08:30:05 +01:00
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END AS "ELSE default";
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One|ELSE default
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---+------------
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4| 4
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1998-12-04 16:36:51 +01:00
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(1 row)
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1999-02-23 08:30:05 +01:00
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QUERY: SELECT '6' AS "One",
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1998-12-04 16:36:51 +01:00
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CASE
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WHEN 1 > 2 THEN 3
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WHEN 4 < 5 THEN 6
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ELSE 7
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1999-02-23 08:30:05 +01:00
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END AS "Two WHEN with default";
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One|Two WHEN with default
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---+---------------------
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6| 6
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1998-12-04 16:36:51 +01:00
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(1 row)
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QUERY: SELECT '' AS "Five",
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CASE
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1999-02-23 08:30:05 +01:00
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WHEN i >= 0 THEN i
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1998-12-04 16:36:51 +01:00
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END AS ">= 0 or Null"
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1999-02-23 08:30:05 +01:00
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FROM CASE_TBL;
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1998-12-04 16:36:51 +01:00
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Five|>= 0 or Null
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----+------------
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1999-02-23 08:30:05 +01:00
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| 1
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| 2
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| 3
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| 4
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(4 rows)
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1998-12-04 16:36:51 +01:00
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QUERY: SELECT '' AS "Five",
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1999-02-23 08:30:05 +01:00
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CASE WHEN i >= 0 THEN (i - i)
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ELSE i
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1998-12-04 16:36:51 +01:00
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END AS "Simplest Math"
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1999-02-23 08:30:05 +01:00
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FROM CASE_TBL;
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1998-12-04 16:36:51 +01:00
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Five|Simplest Math
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----+-------------
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| 0
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| 0
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| 0
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1999-02-23 08:30:05 +01:00
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| 0
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(4 rows)
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QUERY: SELECT '' AS "Five", i AS "Value",
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CASE WHEN (i < 0) THEN 'small'
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WHEN (i = 0) THEN 'zero'
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WHEN (i = 1) THEN 'one'
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WHEN (i = 2) THEN 'two'
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ELSE 'big'
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END AS "Category"
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FROM CASE_TBL;
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Five|Value|Category
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----+-----+--------
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| 1|one
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| 2|two
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| 3|big
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| 4|big
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(4 rows)
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1998-12-04 16:36:51 +01:00
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1999-02-23 08:30:05 +01:00
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QUERY: /*
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SELECT '' AS "Five",
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CASE WHEN ((i < 0) or (i < 0)) THEN 'small'
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WHEN ((i = 0) or (i = 0)) THEN 'zero'
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WHEN ((i = 1) or (i = 1)) THEN 'one'
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WHEN ((i = 2) or (i = 2)) THEN 'two'
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1998-12-04 16:36:51 +01:00
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ELSE 'big'
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END AS "Category"
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1999-02-23 08:30:05 +01:00
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FROM CASE_TBL;
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*/
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SELECT * FROM CASE_TBL WHERE COALESCE(f,i) = 4;
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i|f
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-+-
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4|
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(1 row)
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QUERY: SELECT * FROM CASE_TBL WHERE NULLIF(f,i) = 2;
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i|f
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-+-
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(0 rows)
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QUERY: /*
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This crashes the backend at the moment...
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- thomas 1998-12-12
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SELECT COALESCE(a.i, a.f, b.i, b.j)
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FROM CASE_TBL a, CASE2_TBL b;
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*/
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SELECT *
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FROM CASE_TBL a, CASE2_TBL b
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WHERE COALESCE(a.i, a.f, b.i, b.j) = 4;
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i|f|i| j
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-+-+-+--
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4| |1|-1
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4| |2|-2
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4| |3|-3
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4| |2|-4
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4| |1|
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4| | |-6
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(6 rows)
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QUERY: /*
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This crashes the backend at the moment...
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- thomas 1998-12-12
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SELECT '' AS Five, NULLIF(a.i,b.i) AS "NULLIF(a.i,b.i)",
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NULLIF(b.i, 4) AS "NULLIF(b.i,4)"
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FROM CASE_TBL a, CASE2_TBL b;
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*/
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SELECT '' AS "Two", *
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FROM CASE_TBL a, CASE2_TBL b
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WHERE COALESCE(f,b.i) = 2;
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Two|i|f|i| j
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---+-+-+-+--
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|4| |2|-2
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|4| |2|-4
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(2 rows)
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QUERY: UPDATE CASE_TBL
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SET i = CASE WHEN i >= 0 THEN (- i)
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ELSE (2 * i) END;
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QUERY: SELECT * FROM CASE_TBL;
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i| f
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--+-----
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-1| 10.1
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-2| 20.2
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-3|-30.3
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-4|
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(4 rows)
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QUERY: UPDATE CASE_TBL
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SET i = CASE WHEN i >= 2 THEN (2 * i)
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ELSE (3 * i) END;
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QUERY: SELECT * FROM CASE_TBL;
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i| f
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---+-----
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-3| 10.1
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-6| 20.2
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-9|-30.3
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-12|
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(4 rows)
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1998-12-04 16:36:51 +01:00
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1999-02-23 08:30:05 +01:00
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QUERY: /*
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This crashes the backend at the moment...
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- thomas 1998-12-12
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UPDATE CASE_TBL
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SET i = CASE WHEN b.i >= 2 THEN (2 * j)
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ELSE (3 * j) END
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FROM CASE2_TBL b
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WHERE j = -CASE_TBL.i;
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SELECT * FROM CASE_TBL;
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*/
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DROP TABLE CASE_TBL;
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QUERY: DROP TABLE CASE2_TBL;
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