difference between "on" and "where" when using left/right join query
摘要:I used to put the where-condiction in the "on" substatement in a join query,wishing that can help reducing the join count and improving the performence.But totally i was wrong.It seems the on-condiction is not like the where-condiction in a left/right join query. For example, there are two
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posted @ 2013-04-23 18:38