Omar Alaa Omar Alaa - 1 month ago 12
C# Question

Data type mismatch in criteria expression exception in ms acess database

I'm creating a simple program about now the idea is to insert the data "Person information Name, Age ETC. " inside the database through my c# program and I when I click the button I get this error


System.Data.OleDb.OleDbException (0x80040E07): Data type mismatch in criteria expression.
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 School_System.newRegisteration.button1_Click(Object sender, EventArgs e) in C:\Users\OmarS_000\documents\visual studio 2015\Projects\School System\School System\newRegisteration.cs:line 35


Here is my code

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.OleDb;
using System.ComponentModel;


public partial class newRegisteration : Form

{
private OleDbConnection connection = new OleDbConnection();
public newRegisteration()
{
InitializeComponent();
connection.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\OmarS_000\Documents\Visual Studio 2015\Projects\School System\School System\School.accdb;
Persist Security Info=False;";
}

private void button1_Click(object sender, EventArgs e)
{
try
{
connection.Open();
OleDbCommand command = new OleDbCommand();
command.Connection = connection;
command.CommandText = "INSERT into School ([Name], [Age], [Grade], [Class]) VALUES('" + nameTextBox2 + "', '" + ageTextBox2 + "', '" + gradeTextBox2 + "', '" + classTextBox2 + "') ";

command.ExecuteNonQuery();
MessageBox.Show("Data Saved");
connection.Close();
}
catch (Exception ex)
{
MessageBox.Show("Error" + ex);
}
}
}


line 35 which the error mentioned it contains

command.ExecuteNonQuery();


i get this error when i click on the button, but the codes in the visual studio debugs perfectly with 0 errors. so what spot did i miss right here ?

Answer

You are using value from some textbox so you need to use its Text property to get value

command.CommandText = "INSERT into School ([Name], [Age], [Grade], [Class]) VALUES('" + nameTextBox2.Text + "', '" + ageTextBox2.Text + "', '" + gradeTextBox2.Text + "', '" + classTextBox2.Text + "') ";