Update Single and Multiple Column of the table where condition matched

Suppose we have two tables “Products” and “Customers” and “ProductsId” is a foreign key in the “Customers” table from "Products" table.

Condition 1 - For Single Column update:- Update the “Items” column in Customers from Products “Items”, where Products.Id equals to Customers.ProductsId.

Query:-

UPDATE Customers cust -------à (“cust” alias name of Customers table)

SET cust.Items=(SELECT prod.Items

                            FROM Products prod  ---------à (“prod" alias name of the Products table)

                            WHERE prod.id=cust.productsid); 

Condition 2- For Multiple Column Update:- Update “Items” and “ExpiryDate” from Products where Products.Id equals to Customers.ProductsId.

Query :-

MERGE

INTO     Customers cust -------à (“cust” alias name of Customers table)

USING  (SELECT Id, Items, ExpriyDate FROM Products

              )prod ----------à (“Prod” alias name of the subquery results i.e output of Products table)

ON        (cust.productid=prod.id) --------à (Here we are matching the conditions)

WHEN MATCHED THEN

UPDATE

SET cust.item=prod.items,

        cust.ExpiryDate=prod.ExpiryDate

/*****Here we can add update multiple columns, before that we need to select those columns from Products table in the above subquery ******/

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