Joining in SQL

This article explains how to join tables in SQL Server.

Joining in SQL

There are various type of SQL joinning. A few of them that are commonly used are described below.

1: Inner join

2: Right Outer Join

3: Left Outer join

First Step

First create a SQL table named bio.

The following is the second table named fee.

 

Now insert values into the bio table.



Now insert values into the fee table.

 

Second Step

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Data.SqlClient;

using System.Data;

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

{

    protected void Page_Load(object sender, EventArgs e)

    {

    }

    SqlConnection con = new SqlConnection(@"Data Source=IS9;Initial Catalog=practice;User ID=sa;Password=isource");

    protected void innerJoin_Click(object sender, EventArgs e)

    {

        con.Open();

        SqlCommand cmd=new SqlCommand ();

        cmd.Connection = con;

        cmd.CommandText = "Select * From bio Inner Join fee on bio.id=fee.id";

        SqlDataAdapter da = new SqlDataAdapter(cmd);

        DataSet ds = new DataSet();

        da.Fill(ds);

        GridView1.DataSource = ds;

        GridView1.DataBind();

        con.Close();

    }

    protected void RightOuterJoin_Click(object sender, EventArgs e)

    {

        con.Open();

        SqlCommand cmd = new SqlCommand();

        cmd.Connection = con;

        cmd.CommandText = "Select * From bio Right  Outer Join fee on bio.id=fee.id";

        SqlDataAdapter da = new SqlDataAdapter(cmd);

        DataSet ds = new DataSet();

        da.Fill(ds);

        GridView1.DataSource = ds;

        GridView1.DataBind();

        con.Close();   

    }

 

 

 

    protected void LeftOuterJoin_Click(object sender, EventArgs e)

    {

        con.Open();

        SqlCommand cmd = new SqlCommand();

        cmd.Connection = con;

        cmd.CommandText = "Select * From bio Left Outer Join fee on bio.id=fee.id";

        SqlDataAdapter da = new SqlDataAdapter(cmd);

        DataSet ds = new DataSet();

        da.Fill(ds);

        GridView1.DataSource = ds;

        GridView1.DataBind();

        con.Close();   

    }   

}