＆＃34; AND ..和......之间的差异和＃34;和＆＃34;和（和......和）＆＃34;

Question

我有两个用于oracle 11gr2的语句sql

SQL1：

Select * from tableA inpt, tableB ptbs
where inpt.z='A'
AND (inpt.pid    = ptbs.pid
     AND  inpt.instcd = ptbs.instcd);

SQL2：

Select * from tableA inpt, tableB ptbs
where inpt.z='A'
AND inpt.pid    = ptbs.pid
     AND  inpt.instcd = ptbs.instcd

Sql1比sql2快吗？

写作... and ... and ... and ...慢慢写and (... and ... and (... and ... and ...))？

类似于＆＃34;或＆＃34;？

Answer 1

这里没有区别。

 where inpt.z='A'
    AND (inpt.pid    = ptbs.pid
         AND  inpt.instcd = ptbs.instcd);

或

where inpt.z='A'
AND inpt.pid    = ptbs.pid
     AND  inpt.instcd = ptbs.instcd

或

where inpt.pid    = ptbs.pid
     AND  inpt.instcd = ptbs.instcd and inpt.z='A'

一切都是一样的。

Answer 2

它可能只是写成：

SELECT *
FROM tableA inpt
INNER JOIN tableB ptbs
ON inpt.pid = ptbs.pid
WHERE inpt.instcd = ptbs.instcd
AND inpt.z = 'A'

这可能值得一看：INNER JOIN ON vs WHERE clause