A few days ago I decided to install MySql v1.2.17 and I downloaded a client class library: MySql.Data.dll v5.0.9.0 (by MySQL AB). I included the client classes inside my wrapper class and had it creating, dropping, inserting, and deleting tables..., or so I thought. I guess I never actually looked at the records it was creating from my test class.

Here is the problem: All my row data is always NULL values and I cannot figure out why this is! I broke out the wrapper code and placed base class calls into a simple set of statements as represented here:

public static void MySqlTestInsert()
        {
            string connStr = TestDbWrapper.BuildConnectionString(DbWrapperType.MySql);

            string insertCmd = "INSERT INTO TestDbWrapper " +
                "(FieldInt32, FieldVarchar_50, FieldBoolean, FieldDateTime) Values " +
                "(@FieldInt32, @FieldVarchar_50, @FieldBoolean, @FieldDateTime)";
            using (MySqlConnection conn = (MySqlConnection)DbWrapper.GetDbConnection(DbWrapperType.MySql, connStr))
            {
                try
                {
                    conn.Open();

                    using (MySqlCommand cmd = new MySqlCommand(insertCmd, conn))
                    {
                        cmd.Parameters.Add(new MySqlParameter("@FieldInt32", 10));
                        cmd.Parameters.Add(new MySqlParameter("@FieldVarchar_50", "some text..."));
                        cmd.Parameters.Add(new MySqlParameter("@FieldBoolean", true));
                        cmd.Parameters.Add(new MySqlParameter("@FieldDateTime", DateTime.Now));

                        cmd.ExecuteNonQuery();
                    }
                }
                catch (DbException ex)
                {
                    Console.WriteLine("Exception: {0}\r\n   Stack Trace: {1}", ex.Message, ex.StackTrace);
                }
                finally
                {
                    conn.Close();
                }
            }
        }

I don't get any errors, just NULL values in my columns. I have full schema privileges for the database and am able drop, create, and select just fine--though all the values are NULL because that is how they are being inserted.

Any ideas?

Have you tried using one of the other overloaded versions of Adding parameters where you actually specify the data type of what you are inserting? Might be worth a try.

Ex:

cmd.Parameters.Add(new MySqlParameter("@FieldInt32", SqlDbType.Int, 10));

:( MySQL is bad for your eyes.

I don't know anything about it but typically you add parameters like this:

conn.Open();
        using (SqlCommand cmd = new SqlCommand(query, conn))
        {
          cmd.Parameters.Add(new SqlParameter("@MemberId", SqlDbType.Int)).Value = MemberId;
          cmd.Parameters.Add(new SqlParameter("@MemberSname", SqlDbType.VarChar)).Value = MemberSname;
          cmd.Parameters.Add(new SqlParameter("@MemberFName", SqlDbType.VarChar)).Value = MemberFName;
          cmd.Parameters.Add(new SqlParameter("@Picture", SqlDbType.VarChar)).Value = Picture;
          cmd.Parameters.Add(new SqlParameter("@FName", SqlDbType.VarChar)).Value = FName;
          cmd.ExecuteNonQuery();
        }

Notice how the ctor is (Name, DataType) and the value is set from a result of the Add() method returning an instance of the parameter? I googled around a little and saw other mysql'ers doing it the same way but I don't have those libraries to test with.

Edited 7 Years Ago by sknake: n/a

Thanks for the suggestions, and I did try them. Neither worked, so I looked a little more on the inet and decided to try using the "?" delimiter in place of the "@" symbol--that fixed the problem.

Oh. ODBC driver's don't support named parameters (i'm 99% sure) and only limited OleDb drivers do. Unless it is a microsoft driver usually @Param is not supported. I forgot about that.

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