我必须更新一个由3个表的连接返回的值的字段。
例子:
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，使用在上述条件中连接的其他一些值。
如何在MS SQL Server中做到这一点?
当前回答
MySQL:一般来说，根据你的需求做必要的改变:
UPDATE
shopping_cart sc
LEFT JOIN
package pc ON sc. package_id = pc.id
SET
sc. amount = pc.amount
其他回答
您可以使用以下查询:
UPDATE im
SET mf_item_number = (some value)
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 `sql`
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
为了说清楚…UPDATE子句可以引用FROM子句中指定的表别名。所以在这种情况下im是有效的
通用的例子
UPDATE A
SET foo = B.bar
FROM TableA A
JOIN TableB B
ON A.col1 = B.colx
WHERE ...
你可以在update语句中使用"FROM "子句指定用于确定如何更新以及更新内容的其他表，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，需要提供将这些表绑定在一起的条件和连接操作。
Marc
MySQL:一般来说，根据你的需求做必要的改变:
UPDATE
shopping_cart sc
LEFT JOIN
package pc ON sc. package_id = pc.id
SET
sc. amount = pc.amount
上面没有使用sql，这里有一个基于连接语句更新表的例子。
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%'
