SQL where条件和jion on条件的详解及区别

数据库 发布日期:2024/12/22 浏览次数:1

正在浏览:SQL where条件和jion on条件的详解及区别

sql 语句中where条件和jion on条件的区别

与有很大的差别,请注意!

SELECT TBL_SchemaDetail.MaterialNo, TBL_StockMaterial.SalePrice 
FROM TBL_StockMaterial RIGHT OUTER JOIN 
   TBL_SchemaDetail ON 
   TBL_StockMaterial.MaterialNo = TBL_SchemaDetail.MaterialNo AND 
   TBL_SchemaDetail.SchemaNo = '7411' AND TBL_StockMaterial.SalePrice = 0 

条件全部放到join的on中。

SELECT TBL_SchemaDetail.MaterialNo, TBL_StockMaterial.SalePrice 
FROM TBL_StockMaterial RIGHT OUTER JOIN 
   TBL_SchemaDetail ON 
   TBL_StockMaterial.MaterialNo = TBL_SchemaDetail.MaterialNo 
WHERE (TBL_SchemaDetail.SchemaNo = '7411') AND (TBL_StockMaterial.SalePrice = 0) 

连接和条件分开。

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