How Can I Implement CASE Statement Logic in LINQ for Conditional Value Assignment?

Using CASE statement in LINQ

LINQ (C#) allows the use of CASE statement-like logic to perform conditional value assignments based on specific conditions.

The following code snippet shows how to use the CASE statement to assign a value to the osc_products attribute in the products_quantity table. The assignment rules are as follows:

• If itempromoflag is not equal to 'N', then set products_quantity to 100,000.
• If itemcat1 is equal to '1', '2' or '31' and itemsalestatus is equal to 'S', then set products_quantity to 100,000.
• If itemsalestatus is equal to 'O', set products_quantity to 0.
• Otherwise, set products_quantity to the result of itemqtyonhand minus itemqtycommitted.

To implement this CASE statement in LINQ, you can use a conditional expression in the select clause. An example is as follows:

cdsDBDataContext db = new cdsDBDataContext();
var query = from items in db.cdsItems
            where items.ItemHandHeldFlag == "Y" &&
                  items.ItemQtyOnHand - items.ItemQtyCommitted > 0
            select new
            {
                ItemID = items.ItemID,
                ProductsQuantity = (items.ItemPromoFlag != "N") ? 100000
                                    : (items.ItemCat1 == "1" || items.ItemCat1 == "2" || items.ItemCat1 == "31" && items.ItemSaleStatus == "S") ? 100000
                                    : (items.ItemSaleStatus == "O") ? 0
                                    : items.ItemQtyOnHand - items.ItemQtyCommitted
            };

Note that this LINQ query simplifies the code by combining the CASE statement and the assignment of products_quantity into a single expression in the select clause.

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