这两个sql qry之间的区别是什么? [英] What is the diffrence between these two sql qry?

问题描述

请告诉我差异

please tell me the diff

select supplier.sup_id from supplier,product where supplier.sup_id=product.sup_id
order by supplier.sup_id

select supplier.sup_id from supplier,product where supplier join product  
   supplier.sup_id=product.sup_id
order by supplier.sup_id

推荐答案

在性能方面，它们是完全相同的(至少在SQL Server中是这样)，但是请注意，它们已弃用了隐式外部联接语法."

检查以下线程以了解更多详细信息.

http://stackoverflow.com/questions/5273942/mysql-inner-join-vs-where [ ^ ]

"Performance wise, they are exactly the same (at least in SQL Server) but be aware that they are deprecating the implicit outer join syntax."

check the following thread for more details.

http://stackoverflow.com/questions/5273942/mysql-inner-join-vs-where[^]

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