Part 4. Admin Panel (Adding Subjects) - Part III

In this video, you can see how an admin can add subject based on course, year & semester in admin panel/module using Asp.Net C#

Source Code Starts Here :-

Subject.aspx

<center>

<div style="background-image: url('Images/background1.jpg'); width: 1200px">

    <table align="center" style="height: 340px; width: 391px">

        <tr>

            <td colspan="2" align="center">

                <h2>

                    Add Subject</h2>

                <br />

            </td>

        </tr>

        <tr>

            <td>

                <b>Course: &nbsp;&nbsp;&nbsp;</b></td>

            <td>

                <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" 

                    Height="40px" Width="197px">

                </asp:DropDownList>

            </td>

        </tr>

        <tr>

            <td>

             <b>Year: &nbsp;&nbsp;&nbsp;</b></td>

            <td>

                <asp:DropDownList ID="DropDownList2" runat="server" AutoPostBack="True" 

                    Height="40px" Width="197px" 

                    onselectedindexchanged="DropDownList2_SelectedIndexChanged">

                    <asp:ListItem Value="0" >Select Year</asp:ListItem>

                    <asp:ListItem Value="1">First Year</asp:ListItem>

                    <asp:ListItem Value="2">Second Year</asp:ListItem>

                    <asp:ListItem Value="3">Third Year</asp:ListItem>

                </asp:DropDownList></td>

        </tr>

        <tr>

            <td>

             <b>Semester: &nbsp;&nbsp;&nbsp;</b></td>

            <td>

                <asp:DropDownList ID="DropDownList3" runat="server" AutoPostBack="True" Height="40px" Width="197px">

                    <asp:ListItem Value="0" >Select Semester</asp:ListItem>

                    

                </asp:DropDownList></td>

        </tr>

        <tr>

            <td>

                <b>Subject: &nbsp;&nbsp;&nbsp;</b></td>

            <td>

                <asp:TextBox ID="TextBox1" runat="server" Width="197px" Height="41px" 

                    CausesValidation="True" placeholder="Subject Name"></asp:TextBox>

                <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" 

                    ControlToValidate="TextBox1" 

                    ForeColor="Red" ErrorMessage="Enter Subject Name"></asp:RequiredFieldValidator>

            </td>

        </tr>

        <tr>

            <td colspan="2" align="center">

                <asp:Button ID="Button1" runat="server" Text="Add" Font-Bold="True" 

                    Height="47px" Width="86px" Font-Size="Medium" /></td>

            

        </tr> 

        <tr>

            <td colspan="2">

                <asp:Label ID="Label1" runat="server" Font-Bold="True"></asp:Label></td>

            

        </tr>

        <tr>

            <td colspan="2" align="center">

                <asp:GridView ID="GridView1" runat="server">

                </asp:GridView>

            </td>

        </tr>

    </table>

    <br />

    <br />

    <br />

    <br />

    <br />

    <br />

    <br />

    <br />

    </div>

</center>

Subject.aspx.cs

String str = ConfigurationManager.ConnectionStrings["Connection"].ConnectionString;

    protected void Page_Load(object sender, EventArgs e)

    {

        if(!IsPostBack)

        {

            GridShow();

            ShowSubject();

        }

    }

    private void GridShow() 

    {

        SqlConnection con = new SqlConnection(str);

        SqlCommand cmd = new SqlCommand("select * from Course",con);

        con.Open();

        DropDownList1.DataSource = cmd.ExecuteReader();

        DropDownList1.DataTextField = "CourseName";

        DropDownList1.DataValueField = "CID";

        DropDownList1.DataBind();

        DropDownList1.Items.Insert(0,"Select Course");

        con.Close();

    }

    protected void Button1_Click(object sender, EventArgs e)

    {

        SqlConnection con2= new SqlConnection(str);

        SqlDataAdapter sda1 = new SqlDataAdapter("select * from Subject where CourseName='"+DropDownList1.SelectedItem.Text+"' and Year='"+DropDownList2.SelectedItem.Text+"' and Sem='"+DropDownList3.SelectedItem.Text+"' and SubjectName='"+TextBox1.Text.ToString()+"' ",con2);

        DataTable dt = new DataTable();

        sda1.Fill(dt);

        if (dt.Rows.Count == 1)

        {

            Label1.Text = "The Subject "+TextBox1.Text.ToString()+" is already present for the selected Course="+DropDownList1.SelectedItem.Text+", Year="+DropDownList2.SelectedItem.Text+" and Semester="+DropDownList3.SelectedItem.Text+".";

            Label1.ForeColor = System.Drawing.Color.Red;

        }

        else

        {

            SqlConnection con = new SqlConnection(str);

            SqlDataAdapter sda = new SqlDataAdapter("select CID from Course where CourseName='" + DropDownList1.SelectedItem.Text + "'", con);

            DataSet ds = new DataSet();

            sda.Fill(ds, "Cousre");

            string cousreId = ds.Tables[0].Rows[0]["CID"].ToString();

            SqlConnection con1 = new SqlConnection(str);

            con1.Open();

            SqlCommand cmd = new SqlCommand("insert into Subject(CID,CourseName,Year,SubjectName,Sem) values (@1,@2,@3,@4,@5)", con1);

            cmd.Parameters.AddWithValue("@1", cousreId);

            cmd.Parameters.AddWithValue("@2", DropDownList1.SelectedItem.Text);

            cmd.Parameters.AddWithValue("@3", DropDownList2.SelectedItem.Text);

            cmd.Parameters.AddWithValue("@4", TextBox1.Text);

            cmd.Parameters.AddWithValue("@5", DropDownList3.SelectedItem.Text);

            cmd.ExecuteNonQuery();

            con1.Close();

            Label1.Text = "Subject added successfully";

            Label1.ForeColor = System.Drawing.Color.Green;

            clear();

        }

    }

    private void clear()

    {

        DropDownList1.SelectedValue = "Select Course";

        //DropDownList2.SelectedValue = "Select Year";

        //DropDownList3.SelectedValue = "Select Semester";

        TextBox1.Text = "";

    }

    protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)

    {

        if (int.Parse(DropDownList2.SelectedValue) > 0)

        {

            DataTable statedt = new DataTable();

            statedt.Columns.Add("SemId", typeof(int));

            statedt.Columns.Add("SemName");

            if (DropDownList2.SelectedValue == "1")

            {

                statedt.Rows.Add(1, "Sem I");

                statedt.Rows.Add(2, "Sem II");

            }

            if (DropDownList2.SelectedValue == "2")

            {

                statedt.Rows.Add(3, "Sem III");

                statedt.Rows.Add(4, "Sem IV");

            }

            if (DropDownList2.SelectedValue == "3")

            {

                statedt.Rows.Add(5, "Sem V");

                statedt.Rows.Add(6, "Sem VI");

            }

            DropDownList3.DataSource = statedt;

            DropDownList3.DataTextField = "SemName";

            DropDownList3.DataValueField = "SemId";

            DropDownList3.DataBind();

        }

    }

    private void ShowSubject()

    {

        SqlConnection con = new SqlConnection(str);

        SqlDataAdapter sda = new SqlDataAdapter("select CourseName as Course,Year,Sem as Semester,SubjectName as Subject from Subject", con);

        con.Open();

        DataTable dt = new DataTable();

        sda.Fill(dt);

        GridView1.DataSource = dt;

        GridView1.DataBind();

    }

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