假设两张表把
person表 aid,bid,name,age(人员表)
province表 bid,provincename(省份表)SELECT * FROM person per,province pro WHERE per.bid = pro.bid AND age>40;SELECT * FROM person per,province pro WHERE age>40 AND per.bid = pro.bid;哪一条执行的效率会高?
person表 aid,bid,name,age(人员表)
province表 bid,provincename(省份表)SELECT * FROM person per,province pro WHERE per.bid = pro.bid AND age>40;SELECT * FROM person per,province pro WHERE age>40 AND per.bid = pro.bid;哪一条执行的效率会高?
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