How to insert, update, delete and show data in ASP.Net in C#

Insert Data in Database

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Data;

using System.Data.SqlClient;

namespace DemoClassExample

{

    public partial class _Default : System.Web.UI.Page

    {

        string StrCon = "Server=PRADEEP-HP;Database=Decofloore2;User Id=User_006;password=user006";

        protected void Page_Load(object sender, EventArgs e)

        {        

        }

        protected void btnSave_Click(object sender, EventArgs e)

        {

            SqlConnection SqlCon = new SqlConnection(StrCon);

            string SqlQuery = null;

            SqlQuery = "Insert into ShowOnePage(RegistrationId,Name,Address,MobileNo,Course,Sex,EmailID) values"

                +"('" + txtRegId.Text.Trim() + "','" + txtName.Text.Trim() + "','" + txtAddress.Text.Trim() + "',"

            +"" + txtMobiNo.Text.Trim() + ",'" + txtCourse.Text.Trim() + "','" + ddlGender.SelectedItem.Text + "','" + txtEmailId.Text.Trim() + "')";

SqlCommand SqlComm = new SqlCommand(SqlQuery, SqlCon);

            SqlCon.Open();

            int RecordInserted;

            RecordInserted = SqlComm.ExecuteNonQuery();

            if (RecordInserted > 0)

            {

                Timer1.Enabled = true;

                lblMsg.Text = "Insert Record Successfully";

            }

            else

            {

                lblMsg.Text = "Records are not Inserted";

            }

        }

Update data in database

protected void btnUpdate_Click(object sender, EventArgs e)

        {

            SqlConnection SqlCon = new SqlConnection(StrCon);

            string StrSql = "Update ShowOnePage set Name='" + txtName.Text.Trim() + "',Address='" + txtAddress.Text + "',MobileNo=" + txtMobiNo.Text + ",Course='" + txtCourse.Text + "',Sex='" + ddlGender.SelectedItem.Text + "',EmailID='" + txtEmailId.Text + "' where RegistrationId='" + txtRegId.Text.Trim() + "'";

            SqlCommand SqlCom = new SqlCommand(StrSql, SqlCon);

            SqlCon.Open();

            int RowAffected;

            RowAffected = SqlCom.ExecuteNonQuery();

            if (RowAffected > 0)

            {

                Timer1.Enabled = true;

                lblMsg.Text = "Update Record Successfully";

            }

            else

            {

                lblMsg.Text = "Record are not Updated";

            }

        }

Delete data from database

protected void btnDelete_Click(object sender, EventArgs e)

        {

            SqlConnection SqlCon = new SqlConnection(StrCon);

            string StrSql = "Delete from ShowOnePage where RegistrationId='" + txtRegId.Text.Trim() + "'";

            SqlCommand SqlCom = new SqlCommand(StrSql, SqlCon);

            SqlCon.Open();

            int RowAffected;

            RowAffected = SqlCom.ExecuteNonQuery();

            if (RowAffected > 0)

            {

                lblMsg.Text = "Delete Record Successfully";

            }

            else

            {

                lblMsg.Text = "Record are not Deleted";

            }

        }

 Show data from the database

protected void btnShow_Click(object sender, EventArgs e)

        {

            SqlConnection SqlCon = new SqlConnection(StrCon);

            string SqlQuery = "Select * from ShowOnePage";

            SqlCommand SqlComm = new SqlCommand(SqlQuery, SqlCon);

            SqlCon.Open();

            SqlDataReader dr;

            dr = SqlComm.ExecuteReader(CommandBehavior.CloseConnection);

            GridView1.DataSource = dr;

            GridView1.DataBind();

        }

        protected void Timer1_Tick(object sender, EventArgs e)

        {

            Timer1.Enabled = false;

            Response.Redirect("Default.aspx");

        }

    }

}

Show data through user ID in text box

        protected void tnRegId_Click(object sender, EventArgs e)

        {

            SqlConnection Sqlcon = new SqlConnection(StrCon);

            string SqlQuery = "Select Name,Address,MobileNo,Course,Sex,EmailID from ShowOnePage where RegistrationId='" + txtRegId.Text.Trim() + "'";

            SqlCommand Sqlcomm = new SqlCommand(SqlQuery, Sqlcon);

            Sqlcon.Open();

            SqlDataReader dr;

            dr = Sqlcomm.ExecuteReader(CommandBehavior.CloseConnection);

            if (dr.Read())

            {

                txtName.Text = dr["Name"].ToString();

                txtAddress.Text = dr["Address"].ToString();

                txtMobiNo.Text = dr["MobileNo"].ToString();

                txtCourse.Text = dr["Course"].ToString();

                ddlGender.SelectedItem.Text = dr["Sex"].ToString();

                txtEmailId.Text = dr["EmailID"].ToString();

            }

        }

 https://www.youtube.com/channel/UCKLRUr6U5OFeu7FLOpQ-FSw/videos