Ado.net - the Size property has an invalid size of 0

I'm trying to get output value from DB via ADO.net. There's a client code:

    using (var connection = new SqlConnection(ConnectionString))
    {
        connection.Open();
        SqlCommand command = new SqlCommand("pDoSomethingParamsRes", connection);
        command.CommandType = CommandType.StoredProcedure;
        command.Parameters.Add("@i", 1);
        var outParam = new SqlParameter("@out", SqlDbType.VarChar);
        outParam.Direction = ParameterDirection.Output;
        command.Parameters.Add(outParam);
        command.ExecuteNonQuery();
        Console.WriteLine(command.Parameters["@out"].Value.ToString());
    }

When I run this I get the following exception:

the Size property has an invalid size of 0

Solutions :-

VarChar and NVarChar are variable width character fields (thus var+char). You have to set the length, otherwise the default is zero.

outParam.Size= int.MaxValue

to define maximum value of integer.

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Creating existing column identity in existing table

Hi friends ,

Suppose i have one table " shipmentpincode " , which have following columns :-

 I want to make Id column of this table identity . Then i have to fulfill following steps : -

• First , create a temp column in table 

Alter Table shipmentpincode Add Id_new int Identity(1, 1) not null primary key 

Go

• Second, drop existing column 

Alter Table shipmentpincode Drop Column Id

Go

• Rename new column to old column name 

  Exec sp_rename 'shipmentpincode.Id_new', 'Id', 'Column'

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