Question

sql语句中的a.表名 c.表名 b.表名 是什么意思啊？ 里面 . 是什么意思？

大家帮帮忙分析一下语句的意思，谢谢！SELECT a.FBatchNo, c.FName AS AuxName, b.FName AS stockName, ISNULL(SUM(a.FQty), 0) AS FQty, ISNULL(SUM(a.FSecQty), 0) AS FSecQty, 0 AS Fprice, ISNULL(SUM(a.FBal), 0) AS FAmount, a.FKFDate, a.FPeriodDate, b.FNumber AS StockNumber, c.FNumber AS AuxNumber, b.FItemID, d.FISKFPeriod FROM T_CC_Inventory a INNER JOIN t_Stock b ON a.FStockID = b.FItemID LEFT OUTER JOIN t_AuxItem c ON a.FAuxPropID = c.FItemID INNER JOIN t_ICItem d ON a.FItemID = d.FItemID WHERE (a.FItemID = 89) AND (a.FQty <> 0) AND (a.FStockID = 86) OR (a.FItemID = 89) AND (a.FStockID = 86) AND (a.FBal <> 0) GROUP BY a.FBatchNo, c.FName, b.FName, a.FKFDate, a.FPeriodDate, b.FNumber, c.FNumber, b.FItemID, d.FISKFPeriod 里面的a.表名 c.表名 b.表名 是什么意思啊？ 里面.是什么意思？

Answer 1

是别名 FROM T_CC_Inventory a INNER JOIN t_Stock b ON a.FStockID = b.FItemID LEFT OUTER JOIN t_AuxItem c ON a.FAuxPropID = c.FItemID INNER JOIN t_ICItem d ON a.FItemID = d.FItemID 这里面指定了T_CC_Inventory表用a来代替名称、t_Stock用b来代替等等，这样就可以减少代码量。

Answer 2

a,b,c,d分别是表T_CC_Inventory ,t_Stock ,t_AuxItem ,t_ICItem 的别名 a.FBatchNo表示表T_CC_Inventory 的字段FBatchNo 多表关联查询时为表取别名的好处是防止多表当中有同名字段时出现“未明确定义列”类似异常