CODEWITHSUNDEEP
sqlsql-server
SMHasnain
SMHasnain

Reputation: 706

SQL - Update query only update one field

I am trying to run an update query on my Stock table based on a certain barcode field.

Schema of Stock Table.

enter image description here

The query I am trying to run is

Update tblStock set Quantity = Quantity + 10, Total = Quantity * PPrice where barcode = 'shandar'

when Executing this query the Quantity Field gets updated but Total Field remains unchanged, I want to Multiply Quantity with PPrice.

Thanks in advance.

Upvotes: 4

Views: 5684

Answers (2)

Gordon Linoff
Gordon Linoff

Reputation: 1269543

You can use cross apply to define the new quantity in the FROM clause, and then use that value:

Update s
    set Quantity = v.Quantity,
        Total = v.Quantity * s.PPrice
    from tblStock s cross apply
         (values (s.Quantity + 10)) v(quantity)
    where s.barcode = 'shandar';

Repeating a simple operation such as quantity + 10 isn't a big deal. However, if the calculation is more complex, it is simpler to do it once.

That said, you might be better off with total as a computed column. Then it is just correct -- and never has to be updated. Drop it from the table and then re-add it as:

alter table tblStock add total as ( quantity * pprice );

Then the value of total is always correct, because it is calculated when you query the table.

Upvotes: 2

Thiyagu
Thiyagu

Reputation: 1330

For your case, Once the first column "Quantity" is updated the update statement is not completed ,yet it has to update the Second Column "Total". So it takes the actual records from the table not the updated one. Else you can Split this into 2 updates for Different Columns.

Then You need to do like this:

Because, while updating the table the SQL Server considers the previous data until the code executes successfully without any Error.

This Frequently Updated/Deleted/Inserted rows/records can be viewed by using inserted & deleted tables by using Triggers

Update tblStock set Quantity = Quantity + 10, Total = (Quantity + 10)* PPrice 
where barcode = 'shandar'

Upvotes: 5

Related Questions