Introduction

Here I am performing simple save, delete, search and update operations in a Windows Forms Application using the SqlParameter class. The SqlParamater class is found in the "System.Data.SqlClient" namespace. It is a class of a connected architecture of .NET framework. It represents parameters. We use the SqlParameter class to perform various operations.

Open Visual Studio 2010 and create a Windows Forms Application. Add some UI Controls and arrange them like in the following figure. 

Write the following code

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Data.SqlClient; namespace sqlparamater{    public partial class Form1 : Form    {        public Form1()        {             InitializeComponent();        }        SqlConnection conn;        SqlCommand comm;        string connstr = "database=student;server=.;user=sa;password=wintellect";        private void btnsave_Click(object sender, EventArgs e)        {            conn = new SqlConnection(connstr);            comm = new SqlCommand();

            conn.Open();            // creating instance of SsqlParameter            SqlParameter rollno=new SqlParameter("@rn",SqlDbType.Int);            SqlParameter name = new SqlParameter("@n", SqlDbType.VarChar);            SqlParameter course = new SqlParameter("@c", SqlDbType.VarChar);            SqlParameter city = new SqlParameter("@ci", SqlDbType.VarChar);            // Adding parameter to SqlCommand            comm.Parameters.Add(rollno);            comm.Parameters.Add(name);            comm.Parameters.Add(course);            comm.Parameters.Add(city);            // Setting values             rollno.Value = Convert.ToInt32(txtrollno.Text);            name.Value = txtname.Text;            course.Value = txtcourse.Text;            city.Value = txtcity.Text;            // adding connection to SqlCommand            comm.Connection = conn;            // Sql Statement            comm.CommandText = "insert into student_detail values(@rn,@n,@c,@ci)";             try            {                comm.ExecuteNonQuery();                MessageBox.Show("Saved");                txtcity.Clear();                txtcourse.Clear();                txtname.Clear();                txtrollno.Clear();            }            catch (Exception)            {                MessageBox.Show("Not Saved");            }            finally            {                conn.Close();            }        }        private void btndelete_Click(object sender, EventArgs e)        {            conn = new SqlConnection(connstr);            comm = new SqlCommand();            conn.Open();             SqlParameter rollno = new SqlParameter("@rn", SqlDbType.Int);                       comm.Parameters.Add(rollno);                           rollno.Value = Convert.ToInt32(txtrollno.Text);                       comm.Connection = conn;            comm.CommandText = "delete from student_detail where rollno=@rn"; 

            try            {                comm.ExecuteNonQuery();                MessageBox.Show("Deleted....");                 txtcity.Clear();                txtcourse.Clear();                txtname.Clear();                txtrollno.Clear();                txtrollno.Focus();                            }            catch (Exception)            {                MessageBox.Show("Not Deleted....");            }            finally            {                conn.Close();            }        }         private void btnsearch_Click(object sender, EventArgs e)        {            if (txtrollno.Text == "")            {                MessageBox.Show("Please, Enter Roll No. of Student");            }            else            {                conn = new SqlConnection(connstr);                comm = new SqlCommand();                conn.Open();                 SqlParameter rollno = new SqlParameter("@rn", SqlDbType.Int);                SqlParameter name = new SqlParameter("@n", SqlDbType.VarChar);                SqlParameter course = new SqlParameter("@c", SqlDbType.VarChar);                SqlParameter city = new SqlParameter("@ci", SqlDbType.VarChar);                 comm.Parameters.Add(rollno);                comm.Parameters.Add(name);                comm.Parameters.Add(course);                comm.Parameters.Add(city);                rollno.Direction = ParameterDirection.Input;                name.Direction = ParameterDirection.Output;                course.Direction = ParameterDirection.Output;                city.Direction = ParameterDirection.Output;                 name.Size = 30;                course.Size = 20;                city.Size = 20;                 rollno.Value = Convert.ToInt32(txtrollno.Text);  

                comm.Connection = conn;                comm.CommandText = "select @n=name,@c=course,@ci=city from student_detail where rollno=@rn";                 try                {                    comm.ExecuteNonQuery();                    txtname.Text = name.Value.ToString();                    txtcourse.Text = course.Value.ToString();                    txtcity.Text = city.Value.ToString();                 }                catch (Exception)                {                    MessageBox.Show("Not Found");                }                finally                {                    conn.Close();                }            }        }        private void btnupdate_Click(object sender, EventArgs e)        {            conn = new SqlConnection(connstr);            comm = new SqlCommand();            conn.Open();            SqlParameter rollno = new SqlParameter("@rn", SqlDbType.Int);            SqlParameter name = new SqlParameter("@n", SqlDbType.VarChar);            SqlParameter course = new SqlParameter("@c", SqlDbType.VarChar);            SqlParameter city = new SqlParameter("@ci", SqlDbType.VarChar);

            comm.Parameters.Add(rollno);            comm.Parameters.Add(name);            comm.Parameters.Add(course);            comm.Parameters.Add(city); 

            rollno.Value = Convert.ToInt32(txtrollno.Text);            name.Value = txtname.Text;            course.Value = txtcourse.Text;            city.Value = txtcity.Text;             comm.Connection = conn;            comm.CommandText = "update student_detail set name=@n,course=@c,city=@ci where rollno=@rn";             try            {                comm.ExecuteNonQuery();                MessageBox.Show("Updated....");                txtcity.Clear();                txtcourse.Clear();                txtname.Clear();                txtrollno.Clear();            }

            catch (Exception)            {                MessageBox.Show("Not Updated....");            }            finally            {                conn.Close();            }        }         private void Form1_Load(object sender, EventArgs e)        {         }    }}

Run the application.

Output

You can Save, Delete, Search and Update records.