[MYSQL]Simplifier une requête union
Bonjour,
J'aimerais savoir s'il existe une écriture plus optimisée et plus lisible de la requête suivante ?
Code:
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| SELECT MAX(ind0), MAX(ind1), MAX(ind2), MAX(ind3) FROM(
(SELECT `ind` AS 'ind0', 0 AS 'ind1', 0 AS 'ind2', 0 AS 'ind3'
FROM `table`
WHERE cond1
AND cond2
AND cond3=0
ORDER BY Field1 DESC
LIMIT 1)
UNION
(SELECT 0 AS 'ind0', `ind` AS 'ind1', 0 AS 'ind2', 0 AS 'ind3'
FROM `table`
WHERE cond1
AND cond2
AND cond3=1
ORDER BY Field1 DESC
LIMIT 1)
UNION
(SELECT 0 AS 'ind0', 0 AS 'ind1', `ind` AS 'ind2', 0 AS 'ind3'
FROM `table`
WHERE cond1
AND cond2
AND cond3=2
ORDER BY Field1 DESC
LIMIT 1)
UNION
(SELECT 0 AS 'ind0', 0 AS 'ind1', 0 AS 'ind2', `ind` AS 'ind3'
FROM `table`
WHERE cond1
AND cond2
AND cond3=3
ORDER BY Field1 DESC
LIMIT 1)
) AS temp; |
cond1 et cond2 étant redondants.
J'ai tenté avec
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| CREATE TEMPORARY TABLE tmp SELECT * FROM `table` WHERE cond1 AND cond2;
SELECT MAX(ind0), MAX(ind1), MAX(ind2), MAX(ind3) FROM(
(SELECT `ind` AS 'ind0', 0 AS 'ind1', 0 AS 'ind2', 0 AS 'ind3'
FROM tmp
WHERE cond3=0
ORDER BY Field1 DESC
LIMIT 1)
UNION
(SELECT 0 AS 'ind0', `ind` AS 'ind1', 0 AS 'ind2', 0 AS 'ind3'
FROM tmp
WHERE cond3=1
ORDER BY Field1 DESC
LIMIT 1)
UNION
(SELECT 0 AS 'ind0', 0 AS 'ind1', `ind` AS 'ind2', 0 AS 'ind3'
FROM tmp
WHERE cond3=2
ORDER BY Field1 DESC
LIMIT 1)
UNION
(SELECT 0 AS 'ind0', 0 AS 'ind1', 0 AS 'ind2', `ind` AS 'ind3'
FROM tmp
WHERE cond3=3
ORDER BY Field1 DESC
LIMIT 1)
) AS temp; |
mais comme je tente d"utiliser plusieurs fois la table temporaire, j'ai en retour
Citation:
debug : #1137 - Can't reopen table: 'tmp'{"success":false,"error":"#1137 - Can't reopen table: 'tmp'<\/div>"}
Il y a-t-il une alternative ?
Merci de vos avis.
