How Can LINQ's Ternary Operator Replicate SQL's CASE Statement for Conditional Quantity Updates?

Case Statements in LINQ: A Practical Example

LINQ's powerful CASE statements provide a concise syntax for conditional evaluations within queries. Consider the following requirement for updating stock status in LINQ:

osc_products.products_quantity =
CASE 
    WHEN itempromoflag <> 'N' THEN 100000
    WHEN itemcat1 IN ('1','2','31') AND itemsalestatus = 'S' THEN 100000
    WHEN itemsalestatus = 'O' THEN 0
    ELSE cds_oeinvitem.itemqtyonhand - cds_oeinvitem.itemqtycommitted 
END  

In LINQ, this CASE statement can be written as follows:

var query = from items in db.cdsItems
              where items.ItemHandHeldFlag.Equals("Y") &
              items.ItemQtyOnHand - items.ItemQtyCommitted > 0
              select new
              {
                  Quantity = 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
              };

This query effectively evaluates the CASE statement conditions and assigns the appropriate value to the Quantity property of the anonymous type.

Remember, the overall LINQ statement handles additional criteria such as ItemHandHeldFlag and availability conditions.

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