奇怪的SQL???
执行以下SQL:
select * from pm_historicaldata t
where t.pm_data_id in
(SELECT DISTINCT PM_DATA_ID
FROM PM_DATADETAIL
WHERE MODEL_ID = 2002
AND (DIGITALVALUE = 5000 or digitalvalue = 5003))
-- and t.model_id = 4521
没有返回数据?
select * from pm_historicaldata t
where t.pm_data_id in
(SELECT DISTINCT PM_DATA_ID
FROM PM_DATADETAIL
WHERE MODEL_ID = 2002
AND (DIGITALVALUE = 5000 or digitalvalue = 5003))
and t.model_id = 4521
却可以返回数据?
不知哪些因素会出现这种现象?