SQL update query using joins

Question

I have to update a field with a value which is returned by a join of 3 tables.

Example:

select
    im.itemid
    ,im.sku as iSku
    ,gm.SKU as GSKU         


        

Answer 1

Adapting this to MySQL -- there is no FROM clause in UPDATE, but this works:

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