Question

I have two tables, one is called Product and another one is called ProductVariant. ProductVariant has ID from Product. I need to do simple operation on both tables.

Here is the query that I come up with:

declare @id int

declare cur CURSOR LOCAL for
select @id = ProductID  from Product WHERE (Published = '0')

open cur

fetch next from cur into @id 

while @@FETCH_STATUS = 0 BEGIN

UPDATE Productvariant SET Cost = SalePrice WHERE VariantID = @id;
UPDATE ProductVariant SET SalePrice = 0.00 WHERE VariantID = @id; 

fetch next from cur into @id 
END

close cur
deallocate cur

But it gives me:
Msg 154, Level 15, State 3, Line 4
variable assignment is not allowed in a cursor declaration.

Thanks

Answer 1

I would do something like this instead.

SQL Fiddle

MS SQL Server 2008 Schema Setup:

create table Product
(
  ProductID int,
  Published char(1)
);

create table ProductVariant
(
  VariantID int,
  Cost money,
  SalePrice money
);

insert into Product values
(1, '0'),
(2, '1'),
(3, '0')

insert into ProductVariant values
(1, 0, 10),
(1, 0, 11),
(2, 0, 20),
(2, 0, 21),
(3, 0, 30),
(3, 0, 31);

Query 1:

UPDATE ProductVariant 
SET    Cost = SalePrice, 
       SalePrice = 0.00 
FROM   Product 
WHERE  Product.ProductID = ProductVariant.VariantID AND
       Product.Published = '0';

SELECT *
FROM ProductVariant;

Results:

| VARIANTID | COST | SALEPRICE |
--------------------------------
|         1 |   10 |         0 |
|         1 |   11 |         0 |
|         2 |    0 |        20 |
|         2 |    0 |        21 |
|         3 |   30 |         0 |
|         3 |   31 |         0 |