UPDATE all column values equivalent to another tables column value based on their id

Question

I have this table called shop:

+---------+---------+------------+----------+
| shop_id | item_id | item_price | item_qty |
+---------+--         


        

Answer 1

You can simply do this by joining the tables.

UPDATE  shop a
        INNER JOIN item b
            ON b.item_ID = a.item_ID
SET     a.item_price = b.item_price 

• SQLFiddle Demo

OUTPUT after the UPDATE statement has been executed

╔═════════╦═════════╦════════════╦══════════╗
║ SHOP_ID ║ ITEM_ID ║ ITEM_PRICE ║ ITEM_QTY ║
╠═════════╬═════════╬════════════╬══════════╣
║       1 ║       1 ║        200 ║       99 ║
║       2 ║       2 ║        225 ║       99 ║
║       3 ║       3 ║         55 ║       99 ║
║       4 ║       4 ║        120 ║       99 ║
║       5 ║       5 ║        155 ║       99 ║
║       6 ║       6 ║         50 ║       99 ║
║       7 ║       7 ║        150 ║       99 ║
║       8 ║       8 ║        199 ║       99 ║
╚═════════╩═════════╩════════════╩══════════╝