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This article will explain in detail how to output parameters from LINQ to SQL. The editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

The LINQ to SQL output parameter maps to a reference parameter, and for value types, it declares the parameter to be null.

The following example takes a single input parameter (customer ID) and returns an output parameter (total sales of that customer).

ALTER PROCEDURE [dbo]. [CustOrderTotal] @ CustomerID nchar (5), @ TotalSales money OUTPUT AS SELECT @ TotalSales = SUM (OD.UNITPRICE* (1-OD.DISCOUNT) * OD.QUANTITY) FROM ORDERS O, "ORDER DETAILS" OD where O.CUSTOMERID = @ CustomerID AND O.ORDERID = OD.ORDERID

The generated code is as follows:

[Function (Name= "dbo.CustOrderTotal")] public int CustOrderTotal ([Parameter (Name= "CustomerID", DbType= "NChar (5)")] string customerID, [Parameter (Name= "TotalSales", DbType= "Money")] ref System.Nullable totalSales) {IExecuteResult result = this.ExecuteMethodCall (this, (MethodInfo) (MethodInfo.GetCurrentMethod ()), customerID, totalSales); totalSales = (System.Nullable) (result.GetParameterValue (1)); return (int) (result.ReturnValue);}

We call this stored procedure with the following statement: note that the LINQ to SQL output parameter is passed by reference to support the scenario with the parameter "in/out". In this case, the parameter is only "out".

Decimal? TotalSales = 0; string customerID = "ALFKI"; db.CustOrderTotal (customerID, ref totalSales); Console.WriteLine ("Total Sales for Customer'{0}'= {1V C}", customerID, totalSales)

Statement description: this example uses a stored procedure that returns an Out parameter.

This is the end of this article on "how to output parameters for LINQ to SQL". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

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