我有这个 SQL 语句:
SELECT ABX.ABX_APO_NUMBER,
COUNT(A1.PROCESS_MODE) AS NUM_PLANNING,
COUNT(A2.PROCESS_MODE) AS NUM_SETUP,
COUNT(A3.PROCESS_MODE) AS NUM_OUTPUT
FROM ABX, USER_INSTANCE U, ACTIVE_PROCESS A1,
ACTIVE_PROCESS A2, ACTIVE_PROCESS A3
WHERE U.ABX_APO_NUMBER (+) = ABX.ABX_APO_NUMBER
AND A1.PROCESS_INSTANCE_NUMBER (+) = U.INSTANCE_NUMBER
AND A1.PROCESS_MODE (+)= 'PLANNING'
AND A2.PROCESS_INSTANCE_NUMBER (+) = U.INSTANCE_NUMBER
AND A2.PROCESS_MODE (+) = 'SETUP'
AND A3.PROCESS_INSTANCE_NUMBER (+) = U.INSTANCE_NUMBER
AND A3.PROCESS_MODE (+) = 'OUTPUT'
GROUP BY ABX.ABX_APO_NUMBER
(+) 导致 PG 不适...我可以只删除它们吗,它的意思是一样的吗? Postgres 可以理解的等效项是什么?
最佳答案
这是使用 ANSI-92 JOIN 语法重写的查询:
SELECT a.abx_apo_number,
COUNT(ap1.process_mode) AS NUM_PLANNING,
COUNT(ap2.process_mode) AS NUM_SETUP,
COUNT(ap3.process_mode) AS NUM_OUTPUT
FROM ABX a
LEFT JOIN USER_INSTANCE u ON u.abx_apo_number = a.abx_apo_number
LEFT JOIN ACTIVE_PROCESS ap1 ON ap1.process_instance_number = u.instance_number
AND ap1.process_mode = 'PLANNING'
LEFT JOIN ACTIVE_PROCESS ap2 ON ap2.process_instance_number = u.instance_number
AND ap2.process_mode = 'SETUP'
LEFT JOIN ACTIVE_PROCESS ap3 ON ap3.process_instance_number = u.instance_number
AND ap3.process_mode = 'OUTPUT'
GROUP BY a.abx_apo_number
(+)
是 Oracle 特定的 LEFT OUTER JOIN 语法。要删除它,将要求每个 USER_INSTANCE.instance_number
必须具有所有三种进程模式的值:PLANNING、SETUP 和 OUTPUT - 省略一个,abx_apo_number 将不会显示在输出。
关于sql - 将 Oracle SQL Select 转换为 PostgreSQL Select,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/2268732/