2017-06-15 73 views
-3

例如我有2个查询:这些查询是否相同?

1)

SELECT * FROM unit 
INNER JOIN entity 
WHERE unit.length = entity.length 

2)

SELECT * FROM unit 
INNER JOIN entity ON entity.length = unit.length 

是这些查询等效?

+0

是的,如果第一次工作。从我看来,首先应该是'SELECT * FROM unit,entity WHERE unit.length = entity.length',但这是可怕的代码风格。 – degr

+0

Dupe train:https://stackoverflow.com/questions/44917/explicit-vs-implicit-sql-joins,https://stackoverflow.com/questions/1018822/inner-join-on-vs-where-clause, https://stackoverflow.com/questions/354070/sql-join-where-clause-vs-on-clause?rq=1 .. –

+0

感谢大家,是的,它是一个重复的,下次我会更仔细地看 –

回答

0

是的,这两个查询都会产生相同的结果。