syntax - SQL left join vs multiple tables on FROM line? - Stack Overflow

syntax - SQL left join vs multiple tables on FROM line? - Stack Overflow

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日期:2025-04-27
Most SQL dialects accept both the following queries: SELECT a.foo, b.foo FROM a, b WHERE a.x = b.x SELECT a.foo, b.foo FROM a LEFT JOIN b ON a.x = b.x Now obviously when you need an outer join,... ... The second is preferred because it is far less likely ...看更多