provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified

Mohsen Mohammadi 0

I get the error message when I try to connect to the SQL Server 2005 Database from VisualStudio 2022 and .Net 6 Project (winform).

my project is winform with .net 6 .when i want to connect to remote server that is sql 2005 ,i get error : 26 - Error Locating Server/Instance Specified.

my connectionstring:

"Data Source=192.168.1.88\sqlexpress;User Id=sa;Password=123456gt; Initial Catalog=master"

i can connect to this remote server by ssms

i can connect to this remote server by visualStudio2012 and project .net framework 3.5

i can connect to this remote server with instance of sql 2014 with project .net 6

i can connect to local server with instance of sql 2005 with project .net 6

but i can't connect to remote server 2005 with project .net 6 win form.

Thanks

Jiale Xue - MSFT 33,751 Reputation points Microsoft Vendor

2023-05-25T04:18:45.27+00:00

Hi @Mohsen Mohammadi , Welcome to Microsoft Q&A. Please provide the connection code for .net 6 winform. project? Only project .net 6 can do this and it shouldn't.
Mohsen Mohammadi 0 Reputation points

2023-05-25T20:03:12.0866667+00:00

hi.this is code

Jiale Xue - MSFT 33,751 Microsoft Vendor

I don't know what your add table method is?

Please try the following methods:

public static async void Refresh(DataSet? Dat, string shart, string tbl)
{
    if (Dat != null && Dat.Tables.Contains(tbl))
    {
        Dat.Tables[tbl].Clear();
    }
    else
    {
        AddTable(true, Dat, tbl);
    }

    using (SqlConnection selectConnection = new SqlConnection())
    {
        try
        {
            selectConnection.ConnectionString = Ertebat;
            if (selectConnection.State == ConnectionState.Closed)
            {
                selectConnection.Open();
            }
            SqlCommand command = new SqlCommand(shart, selectConnection);
            command.CommandTimeout = 2500;
            SqlDataAdapter adapter = new SqlDataAdapter(command);

            try
            {
                adapter.Fill(Dat, tbl);
                SqlConnection.ClearAllPools();
            }
            catch (Exception ex)
            {
                // Handle the exception appropriately
            }
        }
        catch (Exception ex)
        {
            // Handle the exception appropriately
        }
    }
}

Jiale Xue - MSFT 33,751 Reputation points Microsoft Vendor

2023-06-01T08:23:10.7233333+00:00

Is there any update in this issue?
Mohsen Mohammadi 0 Reputation points

2023-06-09T17:54:45.6666667+00:00

my problem is sqlconnection.open . i get exception in openning connection.