我找到了许多关于如何在列中添加条件或如何与'max'合并的例子,但我不清楚如何针对这种特殊情况进行操作。
SQL查询。
SELECT IDLOCK, DT, LOCKTYPE, PRODUCTATTRIBUTE, VALUE
FROM LOCKREGISTER LR
LEFT JOIN LOCKTYPES T
ON LR.IDLOCKTYPE = T.IDLOCKTYPE
LEFT JOIN PRODUCTATTRIBUTES PA
ON LR.IDPRODUCT = PA.IDPRODUCT AND (PRODUCTATTRIBUTE = 'CodeSet' OR PRODUCTATTRIBUTE = 'KeySet')
ORDER BY IDLOCK;
你可以做条件激化 。
SELECT IDLOCK, DT, LOCKTYPE,
MAX(CASE WHEN PRODUCTATTRIBUTE = 'CodigoConjunto' THEN PRODUCTATTRIBUTE END),
MAX(CASE WHEN PRODUCTATTRIBUTE = 'CodigoConjunto' THEN VALUE END),
MAX(CASE WHEN PRODUCTATTRIBUTE = 'ClaveConjunto' THEN PRODUCTATTRIBUTE END),
MAX(CASE WHEN PRODUCTATTRIBUTE = 'ClaveConjunto' THEN VALUE END)
FROM LOCKREGISTER LR LEFT JOIN
LOCKTYPES T
ON LR.IDLOCKTYPE = T.IDLOCKTYPE LEFT JOIN
PRODUCTATTRIBUTES PA
ON LR.IDPRODUCT = PA.IDPRODUCT AND
PRODUCTATTRIBUTE IN ('CodigoConjunto','ClaveConjunto')
GROUP BY IDLOCK, DT, LOCKTYPE;