Mysql Delete Query Error on code

Question

Mysql Delete record query error, It shows record deleted successfully but in mysql database it was not deleted in database. how to change query?

private void button9_Click(object sender, EventArgs e)
{
if (ID != 0)
//if (textBox6.Text!= "" && textBox7.Text != "" && textBox8.Text != "")
{
string connectionString;
MySqlConnection cnn;
connectionString = @"Data Source=localhost;Initial Catalog=testDB;User ID=root;Password=mysql";
cnn = new MySqlConnection(connectionString);
string id = textBox6.Text;
string name = textBox7.Text;
string salary = textBox8.Text;
textBox6.Text = "";
textBox7.Text = "";
textBox8.Text = "";
string query = "delete from employee where(employee_id = @employee_id AND employee_name =@employee_name AND employee_salary= @employee_salary)";
using (MySqlCommand cmd = new MySqlCommand(query))
{
cmd.Parameters.AddWithValue("@employee_id", id);
cmd.Parameters.AddWithValue("@employee_name", name);
cmd.Parameters.AddWithValue("@employee_salary", salary);
cmd.Connection = cnn;
cnn.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("Record Deleted Successfully");
cnn.Close();
DisplayData();
ClearData();
}
}
else
{
MessageBox.Show("Please Select Record to Delete");
}
}
}

Answer 1

Hi @Mohamed Rafi N

Please check below code

private void button9_Click(object sender, EventArgs e)    
{    
if (ID != 0)    
//if (textBox6.Text!= "" && textBox7.Text != "" && textBox8.Text != "")    
{    
string connectionString;    
MySqlConnection cnn;    
connectionString = @"Data Source=localhost;Initial Catalog=testDB;User ID=root;Password=mysql";    
cnn = new MySqlConnection(connectionString);    
string id = textBox6.Text;    
string name = textBox7.Text;    
string salary = textBox8.Text;    
textBox6.Text = "";    
textBox7.Text = "";    
textBox8.Text = "";    
string query = "DELETE FROM employee WHERE employee_id=@employee_id AND employee_name=@employee_name AND employee_salary-@employee_salary";    
using (MySqlCommand cmd = new MySqlCommand(query))    
{    
cmd.Parameters.AddWithValue("@employee_id", id);    
cmd.Parameters.AddWithValue("@employee_name", name);    
cmd.Parameters.AddWithValue("@employee_salary", salary);    
cmd.Connection = cnn;    
cnn.Open();    
cmd.ExecuteNonQuery();    
MessageBox.Show("Record Deleted Successfully");    
cnn.Close();    
DisplayData();    
ClearData();    
}    
}    
else    
{    
MessageBox.Show("Please Select Record to Delete");    
}    
}    
}    

As per above code, please the query with values in Database check the value.

DELETE FROM employee WHERE employee_id=@employee_id AND employee_name=@employee_name AND employee_salary-@employee_salary  

In order to verify, please check data in database. Run below query with actual value and see if record comes.

SELECT * FROM employee WHERE employee_id=@employee_id AND employee_name=@employee_name AND employee_salary-@employee_salary  

Replace parameters with actual values.

Answer 2

Sir, i have heard and tried what you said, the below coding is here; if i run coding it shows record deleted successfully but still the record not deleting from database

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Configuration;
using System.Windows.Forms;
using System.Data;
using System.Drawing;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;
using System.Data.SqlClient;

private void DisplayData()
{
string connectionString;
MySqlConnection cnn;
connectionString = @"Data Source=localhost;Initial Catalog=testDB;User ID=root;Password=mysql";
cnn = new MySqlConnection(connectionString);
DataTable dt = new DataTable();
adapt = new MySqlDataAdapter("select * from employee", cnn);
adapt.Fill(dt);
dataGridView1.DataSource = dt;
cnn.Open();
cnn.Close();
}
private void ClearData()
{
textBox6.Text = "";
textBox7.Text = "";
textBox8.Text = "";
ID = 0;
}
private void button9_Click(object sender, EventArgs e)
{
if (textBox6.Text!= "" && textBox7.Text != "" && textBox8.Text != "")
{
string connectionString;
MySqlConnection cnn;
connectionString = @"Data Source=localhost;Initial Catalog=testDB;User ID=root;Password=mysql";
cnn = new MySqlConnection(connectionString);
string id = textBox6.Text;
string name = textBox7.Text;
string salary = textBox8.Text;
textBox6.Text = "";
textBox7.Text = "";
textBox8.Text = "";
string query = "DELETE FROM employee WHERE employee_id=@employee_id AND employee_name=@employee_name AND employee_salary-@employee_salary";
using (MySqlCommand cmd = new MySqlCommand(query))
{
cmd.Parameters.AddWithValue("@employee_id", id);
cmd.Parameters.AddWithValue("@employee_name", name);
cmd.Parameters.AddWithValue("@employee_salary", salary);
cmd.Connection = cnn;
cnn.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("Record Deleted Successfully");
cnn.Close();
DisplayData();
ClearData();
}
}
else
{
MessageBox.Show("Please Select Record to Delete");
}
}