两个表的SQL更新语句

Question

I am using MySQL 5.5 and I have two tables, inventory_items and menu_items. They both have a bin_number which is a string and a location_id which is an integer.

menu_items
invetory_item_id | location_id | bin_number


inventory_items
id | location_id | bin_number

I'd like to update the menu_items inventory_item_id to the id of the inventory_items table where they are equal on bin_number and location_id. I could go through each like this:

update menu_items set inventory_item_id=(select id from inventory_items where 
bin_number='7060'  and location_id=37) where bin_number='7060'  and location_id=37;

Is there a way to say update all menu_items to where the bin_number and location_id are the same between menu_items and inventory_items?

Answer 1

You can use a JOIN in your UPDATE :

 UPDATE menu_items mi 
     JOIN inventory_items ii ON mi.bin_number=ii.bin_number 
         AND mi.location_id=ii.location_id
 SET mi.inventory_item_id = ii.id