Update data in access mdb database in c# form application " syntax error in update statement"

Question

I was working in C# form application with an MS-Access mdb database. I have a database in which I have a table Customers with two columns CustomerId And Balance. Both columns are of integer datatype.

Error I was getting is

System.Data.OleDb.OleDbException: Syntax error in UPDATE statement.

at System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(OleDbHResult hr)
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
at System.Data.OleDb.OleDbCommand.ExecuteNonQuery()
at xml_and_db_test.Form1.button1_Click(Object sender, EventArgs e) in G:\my Documents\Visual Studio 2008\Projects\xml_and_db_test\xml_and_db_test\Form1.cs:line 45

Codes I have tried till now are

try
{
   OleDbConnection con = new 
   OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\\database_for_kissan_Pashu_AhaR_Bills.mdb");

   int balance = Convert.ToInt32(textBox2.Text);
   int id = Convert.ToInt32(textBox1.Text);

   // int recordnumb = int.Parse(recordTextBox.Text);

   //  OleDbConnection oleDbConnection = new            OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Users\\Checkout-1\\Documents\\contact.accdb");    
   OleDbCommand update = new OleDbCommand("UPDATE Customers  SET Balance = '" + balance + "',  WHERE id = " + id + " ", con);

   con.Open();
   update.ExecuteNonQuery();
   con.Close();

   // string queryText = "UPDATE Customers SET Balance = ?, where CustomerId = ?;";
   //string queryText = " 'UPDATE Customers SET Balance =' " + balance+ " ' WHERE CustomerId=  ' " +  id +  " ' " ;

   //OleDbCommand cmd = new OleDbCommand(queryText, con);
   //cmd.CommandType = CommandType.Text;
   //cmd.Parameters.AddWithValue("@balance", Convert.ToInt32(textBox2.Text));
   //cmd.Parameters.AddWithValue("@ID", Convert.ToInt32(textBox1.Text));
   //cmd.Parameters.Add("Balance", OleDbType.Integer).Value = Convert.ToInt32(textBox2.Text);
   //cmd.Parameters.Add("CustomerId", OleDbType.Integer).Value = Convert.ToInt32(textBox1.Text);

   //con.Open(); // open the connection
   ////OleDbDataReader dr = cmd.ExecuteNonQuery();

   //int yy = cmd.ExecuteNonQuery();
   //con.Close();
}
catch (Exception ex)
{
    string c = ex.ToString();
    MessageBox.Show(c);
}

//try
//{
//    OleDbConnection con = new OleDbConnection("Provider = Microsoft.Jet.OLEDB.4.0; Data Source = G:\\my Documents\\Visual Studio 2008\\Projects\\xml_and_db_test\\xml_and_db_test\\bin\\Debug\\database_for_kissan_Pashu_AhaR_Bills.mdb");
//    string queryText = "UPDATE Customers SET Balance = ?, where CustomerId = ?;";

//    OleDbCommand cmd = new OleDbCommand(queryText, con);
//    cmd.CommandType = CommandType.Text;
//    //cmd.Parameters.AddWithValue("@balance", Convert.ToInt32(textBox2.Text));
//    //cmd.Parameters.AddWithValue("@ID", Convert.ToInt32(textBox1.Text));

//    cmd.Parameters.Add("Balance", OleDbType.Integer).Value = Convert.ToInt32(textBox2.Text);

//    cmd.Parameters.Add("CustomerId", OleDbType.Integer).Value = Convert.ToInt32(textBox1.Text);
//    con.Open(); // open the connection
//    //OleDbDataReader dr = cmd.ExecuteNonQuery();

//    int yy = cmd.ExecuteNonQuery();
//    con.Close();

//}
//catch (Exception ex)
//{
//    string c = ex.ToString();
//    MessageBox.Show(c);

//}
//string connetionString = null;
//OleDbConnection connection;
//OleDbDataAdapter oledbAdapter = new OleDbDataAdapter();
//string sql = null;
//connetionString = "Provider = Microsoft.Jet.OLEDB.4.0; Data Source = G:\\my Documents\\Visual Studio 2008\\Projects\\xml_and_db_test\\xml_and_db_test\\bin\\Debug\\database_for_kissan_Pashu_AhaR_Bills.mdb;";
//connection = new OleDbConnection(connetionString);
//sql = "update Customers set Balance = '1807' where CustomerId = '1'";
//try
//{
//    connection.Open();
//    oledbAdapter.UpdateCommand = connection.CreateCommand();
//    oledbAdapter.UpdateCommand.CommandText = sql;
//    oledbAdapter.UpdateCommand.ExecuteNonQuery();
//    MessageBox.Show("Row(s) Updated !! ");
//    connection.Close();
//}
//catch (Exception ex)
//{
//    MessageBox.Show(ex.ToString());
//}

some codes are In comments and some are with every method i'm getting the same error.

Answer 1

As gzaxx said .. Try change this

string queryText = "UPDATE Customers SET Balance = ?, where CustomerId = ?;";

with

string queryText = "UPDATE Customers SET Balance = ? where CustomerId = ?;";

Answer 2

There is a comma after balance in your query. Also you are casting your balance to int32 yet you are inserting it as string because of single quote between it.

"UPDATE Customers  SET Balance = " + balance + "  WHERE id = " + id

this query should work.