linq-to-sql delegate does not take "1" argument

Question

I try to select record from customer id which starts with A but i got this error:

 

• Delegate 'System.Func<Customers,int,bool>' does not take '1' arguments.

 

 

NORTHWINDEF db = new NORTHWINDEF("Integrated Security=sspi");

var products = from p in db.Customers

where p.CustomerID.StartsWith("A")           < --

select p;

 

listBox1.Items.Add(products);

Answer 1

I am not able to reproduce your issue. Is the NORTHWINDEF a LINQ to SQL context?

 

Jim Wooley

www.ThinqLinq.com

 

Answer 2

Hi learner08,

I have tried to test this code snippet in a LINQ to SQL sample, it works fine, please check the code snippet below.

string connectionString = @"Data Source=server-name;database=Northwind;Integrated Security=True;";

                 using (SqlConnection connection = new SqlConnection(connectionString))

                 {

                     connection.Open();

                     NorthWindDataContext db = new NorthWindDataContext(connection);

 

                     var queryResult = from s in db.Customers

                                       where s.CustomerID.StartsWith("V")

                                       select s;

                  }

So I believe there is no error in your above code snippet, perhaps the error is in other code, just review your code closely, or post some of them which probably cause the error.

Regards,

Xun

Answer 3

good to hear from you, but my project planned to use entity framework and i use linq-to-entities such as below, with edmx setup:

 

 

private Project1NTBackupEntities CClientContext;

 

CClientContext = new Project1NTBackupEntities();

cclist cc1 = CClientContext.cclist.Where("it.computername = @computername",

new ObjectParameter("computername", ln)).First();

 

 

before this, i worked on sqlconnection, however i got the error at connection.Open() < --- does not allow remote connection, i try to configure sql server with enabling the remote, still does not work.

Answer 4

Hi ,

Sorry, I am not familiar with LINQ to entity, but you can refer to the following forum which concerns this question.

ADO.NET Entity Framework and LINQ to Entities (Pre-release)

Answer 5

i got one question,

 

NorthWindDataContext db = new NorthWindDataContext(connection);

 

where and how did u declare the NorthWindDataContext? (im using VS2008)

 

Answer 6

Hi learner08,

Well, “NorthWindDataContext” is a LINQ to SQL class, and I generate it by doing the following steps.

1.       Add “LINQ to SQL class” item to the project, named it “NorthWind.dbml”

2.       Open the DBML file in the design view, drag and drop the tables of “Northwind” database from the Server explorer to the DBML file.

And there is a LINQ to SQL class generator tool as well, which is Code Generation Tool (SqlMetal.exe)

Regards,

Xun

 

Answer 7

i got the class from dbml file already, but i also have this in my app.config:

 

<connectionStrings>

<add name="LinqToSQL1.Properties.Settings.NorthwindEFConnectionString"

connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\NorthwindEF.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"

providerName="System.Data.SqlClient" />

</connectionStrings>

 

how do i put it in my code to shorten the connection string:

 

string connectionString1 = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\NorthwindEF.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;";

using (SqlConnection connection = new SqlConnection(connectionString))

{

connection.Open();

NorthWindDataContext db1 = new NorthWindDataContext(connection);

 

var queryResult = from s in db1.Customers

where s.CustomerID.StartsWith("A")

select s;

dataGridView1.DataSource = queryResult;

connection.Close();

}

 

the datagridview1 shows empty ...

Answer 8

Hi,

Would you please create a new thread to ask your new question, in general, one thread just for one question.

Regards,
Xun

Answer 9

Replying for others who may encounter the original issue, "Delegate 'System.Func<Customers,int,bool> does not take '1' arguments':

I recently encountered this issue with Linq to Entities after I had changed a fieldname in my underlying table and refreshed my entity model.  The linq query I had selecting from my ObjectContext still used the old fieldname in the query (i.e. .Where(x => x.OldFieldname == "MyValue").  I got the above error ('Delegate '<mytype>,int,bool> does not take '1' arguments' until I fixed the fieldname.

Answer 10

Found at http://mytechsolutions.blogspot.com/2011/11: 

If you get the error Delegate 'System.Func<entityName,int,bool>' does not take 1 arguments
or
Cannot convert lambda expression to type 'string' because it is not a delegate type
then check the linq query and confirm that the "where" condition has == instead of = .. 
var allProducts = from p in context.Products where p.productID == 1 select p;

Answer 11

I had an error like this, Visual Studio was telling me there was an error.  I had just added the table to my dbml.  I tried building it, and the error went away.