CODEWITHSUNDEEP
c#sql-serversqldataadapter
Not So Sharp
Not So Sharp

Reputation: 1179

SqlDataAdapter.DeleteCommand() works with AddWithValue() but not with Add() - Why?

Microsoft's own documentation provides an example of deleting a record as follows:

// Create the DeleteCommand.
command = new SqlCommand(
    "DELETE FROM Customers WHERE CustomerID = @CustomerID", connection);

// Add the parameters for the DeleteCommand.
parameter = command.Parameters.Add(
    "@CustomerID", SqlDbType.NChar, 5, "CustomerID");
parameter.SourceVersion = DataRowVersion.Original;

adapter.DeleteCommand = command;

But on my system it doesn't work (complaining about missing @CustomerID). Instead, if I replace the 

command.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID");

above with 

command.Parameters.AddWithValue("@CustomerID", 5);

It works.

Why?

Upvotes: 3

Views: 1709

Answers (1)

ScottE
ScottE

Reputation: 21630

In this line:

command.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID");

In this overload, 5 refers to the length of the parameter, not the value. If you want to add the value, you'll have to add the following:

command.Parameters["@CustomerID"].Value = "5";

Upvotes: 5

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