How Can I Replicate SQL CASE Statements Using LINQ?

LINQ Implementation of CASE Statements

In LINQ, you can use conditional statements to simulate the functionality of CASE statements found in SQL. Let's examine a specific example:

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  

To convert this CASE statement to LINQ, you can use the following approach:

// Linq syntax
var query = from items in db.cdsItems
            where items.ItemHandHeldFlag.Equals("Y") && 
            items.ItemQtyOnHand - items.ItemQtyCommitted > 0
            select items;

// Alternate lambda syntax with expression body
var query2 = db.cdsItems
    .Where(items => items.ItemHandHeldFlag.Equals("Y") && 
            (items.ItemQtyOnHand - items.ItemQtyCommitted > 0))
    .Select(items => items);

This query effectively simulates the CASE statement behavior and updates the stock status from production to the commerce site as intended.

Note that LINQ provides a more concise and maintainable way to handle conditional statements compared to using CASE statements in SQL. It allows you to use a single statement to evaluate multiple conditions and produce the desired output.

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