Implement check all checkbox functionality in ASP.Net GridView control using JavaScript

I am explaining how to make use JavaScript check box in gridview.

I have a gridview with id="grdata" and bind from database like below code

Aspx Part:-

Now i add a javascript funcation with name "CheckAllEmp" which are call in gridview checkbox control.

javascript funcation like this

<script type="text/javascript" language="javascript">

        function CheckAllEmp(Checkbox) {

            var GridVwHeaderChckbox = document.getElementById("<%=grdata.ClientID %>");

            for (i = 1; i < GridVwHeaderChckbox.rows.length; i++) {

                GridVwHeaderChckbox.rows[i].cells[0].getElementsByTagName("INPUT")[0].checked = Checkbox.checked;

            }

        }

    </script>

This is gridview aspx code which are binding from database

 <asp:GridView runat="server" ID="grdata" AutoGenerateColumns="false" DataKeyNames="UserName" AllowPaging="True" >

     <Columns>

        <asp:TemplateField>

            <HeaderTemplate>

              <asp:CheckBox ID="chkHeader" runat="server" onclick="CheckAllEmp(this);" />

             </HeaderTemplate>

              <ItemTemplate>

               <asp:CheckBox runat="server" ID="chck" />

              </ItemTemplate>

         </asp:TemplateField>

         <asp:TemplateField HeaderText="Name">

            <ItemTemplate>

            <asp:Label runat="server" ID="lblName" Text='<%#Eval("Name")%>'> </asp:Label>

             </ItemTemplate>

          </asp:TemplateField>

          <asp:TemplateField HeaderText="Mobile">

             <ItemTemplate>

          <asp:Label runat="server" ID="lblMobile" Text='<%#Eval("Mobile") %>'> </asp:Label>

         </ItemTemplate>

         </asp:TemplateField>

       <asp:TemplateField HeaderText="ID">

           <ItemTemplate>

           <asp:Label runat="server" ID="lblid" Text='<%#Eval("UserName") %>'> </asp:Label>

          </ItemTemplate>

      </asp:TemplateField>

      <asp:TemplateField HeaderText="Address">

          <ItemTemplate>

         <asp:Label runat="server" ID="lblAddress" Text='<%#Eval("Address") %>'> </asp:Label>

      </ItemTemplate>

    </asp:TemplateField>

    <asp:TemplateField HeaderText="Email">

      <ItemTemplate>

     <asp:Label runat="server" ID="lblEmail" Text='<%#Eval("emailid") %>'></asp:Label>

        </ItemTemplate>

        </asp:TemplateField>

          </Columns>

  </asp:GridView>

CS Code Part:-

void bind()

    {

        try

        {

            Connection.con.Open();

            SqlCommand cmd = new SqlCommand("select * from table  order by id desc", Connection.con);

            SqlDataAdapter da = new SqlDataAdapter(cmd);

            DataTable dt = new DataTable();

            da.Fill(dt);

            if (dt.Rows.Count > 0)

            {

                grdata.DataSource = dt;

                grdata.DataBind();

            }

            else

            {

                dt.Rows.Add(dt.NewRow());

                grdata.DataSource = dt;

                grdata.DataBind();

                int count = grdata.Rows[0].Cells.Count;

                grdata.Rows[0].Cells.Clear();

                grdata.Rows[0].Cells.Add(new TableCell());

                grdata.Rows[0].Cells[0].ColumnSpan = count;

                grdata.Rows[0].Cells[0].Text = "There is no record in your DataBase..";

            }

        }

        catch (Exception ex)

        {

         

        finally

        {

            Connection.con.Close();

        }

    }

This method call on page load like this

protected void Page_Load(object sender, EventArgs e)

    {

        if (!IsPostBack)

        {

            bind();

          

        }

    }

Out Put Like This

How to drop or delete all tables from database with one SQL query

How to drop all tables from database with one SQL query?

You can write query like this:

USE Databasename

SELECT  'DROP TABLE ' + name + ';'
FROM    sys.tables

You can copy and paste into a new SSMS window to run it.

How to Find Nth/Second Highest and Lowest Salary in SQL

We will explore the answer with a series of scenarios and questions asked in relation to finding the highest, lowest, and nth highest salary.

+----+---------+-----------+
| Id | Amount  |  Name     |
+----+---------+-----------+
| 1  | 1100    |   Peter   |
| 2  | 1200    |   Sachin  |
| 3  | 1300    |   Roberts |

| 4 | 1400   |   Shyam  |
+----+---------+-----------+

suppose table name is tbl_TeacherPay

(A) Find the Employee with the Highest Salary

SELECT Name, Amount

FROM

(

Select Name, Amount, ROW_NUMBER() OVER(Order by Amount Desc) as Salary_Order

from   tbl_TeacherPay

) DT

WHERE DT. Salary_Order = 1 ;

(B)Finding the Employee with the Nth Highest Salary

So Query is

SELECT Name, Amount

FROM

(

Select Name, Amount, ROW_NUMBER() OVER(Order by Amount Desc) as Salary_Order

from   tbl_TeacherPay

) DT

WHERE DT. Salary_Order = 3 ;

Result

+----+---------+-----------+
| Id | Amount  |  Name     |
+----+---------+-----------+
| 1  | 1200    |  Sachin   |

+----+---------+-----------+

(C)Finding the Employee with the Lowest Salary

SELECT Name, Amount

FROM

(

Select Name, Amount, ROW_NUMBER() OVER(Order by Amount asc) as Salary_Order

from   tbl_TeacherPay

) DT

WHERE DT. Salary_Order = 1 ;

(D)Find the Employee with the Highest Salary When There Is a Tie (Two employees both have the highest salary and the number is the same)

SELECT Name, Amount

FROM

(

Select Name, Amount, ROW_NUMBER() OVER(Order by Amount desc) as Salary_Order

from   tbl_TeacherPay

) DT

WHERE DT. Salary_Order = 1 ;

Second Highest Salary in MySQL and SQL Server

Write a SQL query to get the second highest salary from the table.

+----+---------+
| Id | Amount  |
+----+---------+
| 1  | 1100    |
| 2  | 1200    |
| 3  | 1300    |
+----+---------+

For example, given the above a table , the second highest salary is 1200. If there is no second highest salary, then the query should return NULL.

suppose table name is tbl_TeacherPay

So Query is

SELECT TOP 1 Amount FROM

( SELECT TOP (2) Amount FROM tbl_TeacherPay

ORDER BY AmountDESC)

AS tbl_TeacherPay order by Amount asc

Result

+----+---------+
| Id | Amount  |
+----+---------+
| 1  | 1200    |

+----+---------+