使用连接的SQL更新查询
我必须更新一个由3个表连接返回的值的字段。
例：
select im.itemid ,im.sku as iSku ,gm.SKU as GSKU ,mm.ManufacturerId as ManuId ,mm.ManufacturerName ,im.mf_item_number ,mm.ManufacturerID from item_master im, group_master gm, Manufacturer_Master mm where im.mf_item_number like 'STA%' and im.sku=gm.sku and gm.ManufacturerID = mm.ManufacturerID and gm.manufacturerID=34 我想更新表item_master的mf_item_number字段值与在上述条件下加入的其他值。
我如何在MS SQL Server中执行此操作？
UPDATE im SET mf_item_number = gm.SKU --etc FROM item_master im JOIN group_master gm ON im.sku = gm.sku JOIN Manufacturer_Master mm ON gm.ManufacturerID = mm.ManufacturerID WHERE im.mf_item_number like 'STA%' AND gm.manufacturerID = 34
为了清楚起见… UPDATE子句可以引用FROM子句中指定的表别名。 所以im在这种情况下是有效的
通用示例
UPDATE A SET foo = B.bar FROM TableA A JOIN TableB B ON A.col1 = B.colx WHERE ...
最简单的方法之一是使用公用表表达式（因为你已经在SQL 2005上）：
with cte as ( select im.itemid ,im.sku as iSku ,gm.SKU as GSKU ,mm.ManufacturerId as ManuId ,mm.ManufacturerName ,im.mf_item_number ,mm.ManufacturerID , <your other field> from item_master im, group_master gm, Manufacturer_Master mm where im.mf_item_number like 'STA%' and im.sku=gm.sku and gm.ManufacturerID = mm.ManufacturerID and gm.manufacturerID=34) update cte set mf_item_number = <your other field>
查询执行引擎将自行找出如何更新记录。
适应这个到MySQL – 在UPDATE没有FROM子句，但是这个工作：
UPDATE item_master im JOIN group_master gm ON im.sku=gm.sku JOIN Manufacturer_Master mm ON gm.ManufacturerID=mm.ManufacturerID SET im.mf_item_number = gm.SKU --etc WHERE im.mf_item_number like 'STA%' AND gm.manufacturerID=34
您可以在UPDATE语句中指定用于确定如何更新和使用“FROM”子句进行更新的附加表，如下所示：
update item_master set mf_item_number = (some value) from group_master as gm join Manufacturar_Master as mm ON ........ where .... (your conditions here)
在WHERE子句中，您需要提供条件和联接操作来将这些表绑定在一起。
渣子
没有使用你的SQL以上，但这是一个基于联合声明更新表的例子。
UPDATE p SET p.category = c.category FROM products p INNER JOIN prodductcatagories pg ON p.productid = pg.productid INNER JOIN categories c ON pg.categoryid = c.cateogryid WHERE c.categories LIKE 'whole%'
MySQL: In general, make necessary changes par your requirement: UPDATE shopping_cart sc LEFT JOIN package pc ON sc. package_id = pc.id SET sc. amount = pc.amount
像这样尝试…
Update t1.Column1 = value from tbltemp as t1 inner join tblUser as t2 on t2.ID = t1.UserID where t1.[column1]=value and t2.[Column1] = value;
