SQL語句AND 和 OR執行的優先級

例句：

SELECT COUNT(1) FROM RT_CUSTALLOCRESULT 
WHERE REGDATE BETWEEN '2014-03-01' AND '2014-03-31' 
OR (DATE(NEXTTRACKDATE) BETWEEN '2014-03-01' AND '2014-03-31') AND SALEID = 2003 

 

SELECT COUNT(1) FROM RT_CUSTALLOCRESULT 
WHERE (REGDATE BETWEEN '2014-03-01' AND '2014-03-31' 
OR (DATE(NEXTTRACKDATE) BETWEEN '2014-03-01' AND '2014-03-31')) AND SALEID = 2003 

 

沒帶括號前，優先執行

(DATE(NEXTTRACKDATE) BETWEEN '2014-03-01' AND '2014-03-31') AND SALEID = 2003 

帶了括號后，優先執行

(REGDATE BETWEEN '2014-03-01' AND '2014-03-31' 
OR (DATE(NEXTTRACKDATE) BETWEEN '2014-03-01' AND '2014-03-31'))