Introdution to SQL server

A complete step by step reference for SQL Server :-

Microsoft SQL Server is a computer application used to create desktop, activity, and web-based database applications.SQL (Structured Query Language) is a very powerful server commanding language, used to create and query databases. It is used at different levels of web server database management with high range of goals. Its movable syntax makes it easy to learn, but perfection its involved architecture may take a little bit longer.

SQL Syntax—select student name class from students where class<> ’science’

What is SQL?

•    SQL stands for Structured Query Language
•    SQL lets you access and manipulate databases

What Can SQL do?

•  Execute queries in opposition to a database
•  Retrieve data from a database
•  Insert records in a database
•  Update records in a database
•  Delete records from a database
•  Create new databases
•  Create new tables in a database
•  Create stored procedures in a database
•  Create views in a database


RDBMS(Relational Database Management System):-

RDBMS stands for Relational Database Management System.RDBMS is the basis for SQL, and for all contemporary database systems such as MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access.The data in RDBMS is stored in database objects called tables.
A table is a collection of related data entries and it consists of columns and rows.

SQL Syntax

Database Tables

A database most frequently contains one or more tables. Each table is recognized by a name (e.g. "Students_Info" or "Section"). Tables contain records (rows) with data.
Below is an example of a table called "Student":

The table above three records and five columns.

How to Create Database?

Create Database-

How to create Table?

Create table

CREATE TABLE Table_name
 (
 Column _name1 data type,
 Column _name2 data type,
 Column_ name 3 data type,
 Column _name4 data type,
…………………………………
 )



Example:-
CREATE TABLE student
 (
 Stu_Id int,
 L_Name varchar(50),
 F_Name varchar(50),
 Add  varchar(50),
 City varchar(50)
 )
Now create table student:

Stu_Id

L_Name

F_Name

Add

City

How to insert record in table?

Insert record in table:we can use insert into command .
As
insert into student values(1,'Singh','Pankaj','B-10','Lucknow')
insert into student values(2,'Singh','rani','c-23','Dehradun')
insert into student values(3,'Ranjan','Rajesh','d-11','Delhi')
select *from student
After having this command your table will look like this.

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	rani	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

The table above three records and five columns.

SQL Statements

If you will select all record in the “student” table:
See the SQL command written below

Select  *from  student

                                          Show all record in a student table

SQL (structure Query Language)
SQL divide in a two part
We use the following SQL statement:

DML (Data manipulation Language
The query and update commands form the Data Manipulation Language part of SQL:

• SELECT - extracts data from a database

            Now Explain Query of DML
 The SQL select statement:--The select statement is used to select data        from a database.
See the SQL command written below

Select *from table_name

Example-table name “student”

Select *from student

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	rani	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

And if you want choose only content of the column as F_Name and Add..

Use select command-

Example-

Select F_name,Add from  student

Output is-

F_Name	Add
Pankaj	B-10
rani	C-23
Rajesh	d-11

• UPDATE - updates data in a database

The UPDATE Command:

The update command used to update record in a table.
See the SQL command written below

Update table_name set column1=value…..where column=value

Now we want to update the student "rani" in the "student" table.
Example-

Update student set F_name=’Ranchiki’ where Add=’c-23’

Output:-

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

SQL DELETE Command:

• DELETE - deletes data from a database

The delete command is used to delete row in a table.
See the Sql command written below

Delete from table_name where column=value..

Now we want to delete Row , the student "Rajesh" in the "student" table.
Example-

Delete from student  where F_name=’Rajesh’

Output is:-

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun

Note **If you want to delete all rows in a table then we want to use

Delete *from student

SQL Insert into  Command:

• INSERT INTO - inserts new data into a database

INSERT INTO allows us to insert multiple rows into a table
See the Sql command written below

INSERT INTO  "table_name"  ("column1", "column2", ...) VALUES ("value1", "value2", ...)

Output

INSERT INTO student (Stu_Id, F_Name, L_Name,Add,City) VALUES (4,'Vijay', ‘Singh’, 'a-21',’Lucknow’)

Now create one new row student table .

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi
4	Singh	Vijay	a-21	Lucknow

Some other command in Sql server when we can use 

The SELECT DISTINCT  keyword allows us to grab all information from a column (or columns) on a table that there will be redundancies

See the Sql command written below

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

See the Sql command written below

SELECT DISTINCT "column_name" FROM "table_name"

Output:

SELECT DISTINCT F_Name  FROM  student

F_Name
Pankaj
Ranchiki
Rajesh

And &  Or Operator: 

The AND operator displays a record if both the first condition and the second condition is true.

And Operator:

 

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

Syntax-

Select *from student where F_Name=’Ranchiki’ and L_Name=’Singh’

Output:-

Stu_Id	L_Name	F_Name	Add	City
2	Singh	Ranchiki	C-23	Dehradun

Or Operator: 

The OR operator displays a record if either the first condition or the second condition is true.

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

Syntax-

Select *from student where F_Name=’Ranchiki’ or F_Name=’Pankaj’

Output:-

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun

SQL Commands  In : 

There are two uses of the IN keyword ,value of the returned values we want to see for at least one of the columns

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

Syntax-

WHERE "column_name" = 'value1'

Examples:-

SELECT * FROM  student  Where F_Name IN (‘Pankaj’, 'Ranchiki')

Output:-

F_Name

Pankaj

Ranchiki

Like SQL Command:

LIKE allows you to do a search based on a pattern rather than specifying exactly what is desired (as in IN) or spell out a range

Syntax

SELECT  "column_name" FROM  "table_name" WHERE  "column_name"  LIKE {PATTERN }

Note:find all Student Name  whose name contains 'AN'

SELECT * FROM  student WHERE  F_Name  LIKE '%AN%'

Output:

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun

The ORDER BY Keyword:

It is used to sort the result-set by a particular column.
The ORDER BY keyword sort the records in ascending order.
If you want to sort the records in a descending order, you can use the DESC keyword.

Syntax: By

Default ascending order record show.

SELECT column_name(s)FROM table_name ORDER BY column_name(s) ASC

Cmd-

SELECT * FROM Student ORDER BY F_Name

Output:

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

Order By DESC Command:-

It is used to short descending order.

Syntax:

SELECT column_name(s) FROM table_name ORDER BY column_name(s)ESC

Cmd:

SELECT column_name(s)FROM table_name ORDER BY column_name(s) ESC

OUTPUT:

Stu_Id	L_Name	F_Name	Add	City
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi
1	Singh	Pankaj	B-10	Lucknow

Primary Key constraint:-

                                  The primary key of a relational table uniquely identifies each record in the table. It can either be a normal attribute that is an unique .Primary keys may consist of a single attribute or multiple attributes in combination.A primary key column cannot contain NULL values.Each table should have a primary key, and each table can have only ONE primary key.







                                       or

The primary Key is a column in a table that uniquely identifies the row in that table.
Table Name------Student
Stu_Id(Set primary Key) DataType(int)
F_Name –Data Type varchar(50)
L_Name—Data Type varchar(50)
Add—Data Type varchar(50)
City—Data Type varchar(50)

Now generate primary key in student table at Stu_Id

CREATE TABLE student
 (
 Stu_Id int NOT NULL PRIMARY KEY,
 L_Name varchar(50) ,
 F_Name varchar(50),
 Add varchar(50),
 City varchar(50)
 )

If you have already created table and still there is no any primary key you have made then you need to write command like this:-

alter table student add primary key(Stu_Id)

Let say if you want to make primary key in your table student in the column stu_id it should be not null at the time of creating your table named student.

SQL FOREIGN KEY Constraint

Why we use foreign key?

Here, let say if we have two table and I want to make relation between them for that we need to use Foreign key. But there are a lot’s of point that we should keep in mind for Example:-
There must be a uniqe column in both table containing same data types.

At first you should create second table.
Now create second table:

CREATE TABLE Info
 (
 Roll_No int NOT NULL PRIMARY KEY,
 Section varchar(50) ,
 Stu_Id int Not Null
  )

Now Create Foreign key for Stu_Id

ALTER TABLE Info ADD FOREIGN KEY (Stu_Id) REFERENCES student (Stu_Id)

                    Or
If you want to generate a foreign key easily method then you can use

1-Go to second table and select Stu_id then right click relationship click .2- now click add and go to tables and columns specifies



3-tables and columns now generate foreign key.

Join:-

Definition-The SQL JOIN command is used to join the data contained in two relational database tables based upon a common attribute.

Here these are two table one is student and other one is Info first table (student have a Stu_Id (Primary Key) and other one is table (Info) Stu_Id (Foreign key).

Student table: 

Stu_Id	L_Name	F_Name	Add	City
1	Singh	Pankaj	B-10	Lucknow
2	Singh	Ranchiki	C-23	Dehradun
3	Ranjan	Rajesh	d-11	Delhi

Info table:

Roll_No	Section	Stu_Id
101	Science	1
102	Art	2
103	Commerce	3

If you want to show join two table you should Join command use.
 Select *from student tb1 join info tb2 on                  tb2.Stu_Id = tb1.Stu_Id
Now the table will look like this:

Stu_Id	L_Name	F_Name	Add	City	Roll_No	Section	Stu_Id
1	Singh	Pankaj	B-10	Lucknow	101	Science	1
2	Singh	Ranchiki	C-23	Dehradun	102	Art	2
3	Ranjan	Rajesh	d-11	Delhi	103	Commerce	3

Inner Join-

Inner Join basically used to join the row which is common in both table.
Here these are two table one is Employee and other one is dep_Emp first table (Employee have a Emp_Id (Primary Key) and other one is table (dep_Emp) Emp_Id (Foreign key).
First Table Name Employee:

Emp_Id	Emp_Name
1	Sagar
2	Ashish
3	Rajesh

Second table Name dep_Emp:

Dep_Id	project_Id	Emp_Id
101	11	1
102	14	1
103	12	2
104	13	2

Now give the Inner join:
 SELECT Employee.Emp_Name, dep_Emp.project_Id
 FROM Employee
 Inner JOIN dep_Emp
 ON Employee.Emp_Id=dep_Emp.Emp_Id
 ORDER BY Employee.Emp_Name
Result will be look like this:

Emp_Name	Project_Id
Ashish	12
Ashish	13
Sagar	11
Sagar	14

Equi Join:-

Equi Join returns all the columns from both tables and filters the records if matching order then use ‘ON ‘statement.
Note: Columns need to specify.

Natural Join:-
It should be specify column where you should keep natural join.

Left Outer Join-:
These keywords revisit all rows from the left table .Unmatched row in the right table do not come into   sight.
select *from Employee t11 left outer join dep_Emp t22 on t11.Emp_Id=t22.Emp_Id
               or
SELECT Employee.Emp_Name, dep_Emp.dep_Id
 FROM Employee
 LEFT JOIN dep_Emp
 ON Employee.Emp_Id=dep_Emp.Emp_Id
 ORDER BY Employee.Emp_Name

Right Outer Join :-
These keywords revisit all rows from the Right table .Unmatched row in the left table do not come into   sight.
select *from Employee t1 right outer join dep_Emp t2 on t1.Emp_Id=t2.Emp_Id

The DDL(Data definition Language) part of SQL permits database tables to be created or deleted.
Statements in SQL are:

Create Data base:-
It is used to create database.
Syntax: Create database database_Name
Example:-create database customer
Now create new database name is customer.

Alter Database:
Alter statement is used to modify the database.

Create Table:-
Create statement is used to create a new table.
Syntax:-create table table_name
{
Column1 data type,
Column2 data type,
……
………
}
Example:-
Create table student
{
Stu_Id int,
F_Name varchar(50),
L_Name varchar(50),
Address varchar(50),
City varchar(50),
}
Now Create New table written in below:

Stu_Id

F_Name

L_Name

Address

City

Alter Table:-
Alter table is used to modify, add, delete columns.
Syntax:-alter table table_name add column_name datatype
Example:-alter table student add column state_Name varchar(50)

Drop column :
Syntax:-Alter table student drop column  state_Name

Modify column :
Syntax:- alter table table_name modify column_name(data type)

Create Index:-Index is mainly used for duplicat values.
Syntax:-create index index_name on table_name(column_name)

Drop Index:-To drop index in a table
Syntax:-drop index index_Name on table_name

How to define a View?

View:-
You can explain simply way that view is used to make a table virtual or make a map same table.
A view comprise of a stored query get-at-able as a virtual table in a relational database.
Views can constitute a subset of the data include in a table.
Views can join and simplify multiple tables into a single virtual table.

How to Create View?

First you should select database (Employee_Record) and give the command.

Create view:

Create a view
create view viewemp
as
select *from Employee

How to  do show Operation ?

use Employee_Record
select *from Employee
How to do update operation  ?

Update view:-

use Employee_Record
update Employee set Emp_Name='pankaj' where Emp_Id=1
How to do delete operation?

Delete  view:-

use Employee_Record
drop  view virtualemp
                                                               
Define Trigger and Type of trigger.How to use trigger with example?

Trigger :  It is a special type of store procedure that is automatically execute in a database .There  are two type  of Trigger first is After trigger and second is instead of Trigger.

Syntax of Trigger:-

CREATE TRIGGER (or Replace Trigger)  trigger_name

{BEFORE | AFTER | INSTEAD OF  }

{INSERT [OR] | UPDATE [OR] | DELETE}

[OF col_name]

ON tab_name

[REFERENCING OLD AS o NEW AS n]

[FOR EACH ROW]

WHEN (condition)

BEGIN

--- sql statements write

END;

Type of Trigger :-

      DML (Data manipulation Language) Trigger

      DDL (Data Definition Language) Trigger

      Logon Trigger

Explain In brief :-

DML(Data Manipulation Language) Trigger:- According to DML trigger in create statement s(Insert, Update and Delete).

DDL(Data Definition Language) Trigger :- According to DDL trigger in create statements(Create, Drop and Delete)

Data Manipulation Language Trigger are two types-

i)                    After trigger(Using For/After Clause)

ii)                  Instead of trigger  (Using instead of clause)

After Trigger:-   Here we will explain after insert trigger, update trigger, delete trigger.

First of all we will create New Table for example:-

- First create table office_details

v  CREATE TABLE employee_details

(

Emp_ID int identity,

Emp_Name varchar(60),

Emp_Sal decimal (18,0)

)

-- Here we will  Insert records ---

Insert into Employee_details values ('Pankaj',2000);

Insert into Employee_Demo values ('Gaurav',1800);

Insert into Employee_Demo values ('Rani',1600);

Insert into Employee_Demo values ('Avanish',1900);

Insert into Employee_Demo values ('Vijay',2100);

--Now create table Employee_performance --

(

Emp_ID int,

Emp_Name varchar(60),

Emp_Sal decimal(18,0),

Emp_perform varchar(150),

Time_perform datetime

)

i)After Insert Trigger:- 

We will create trigger in table, than process insert new record   in a table we will insert trigger and insert query than fetch record.

v  Create trigger on table employee_details for Insert statement

CREATE TRIGGER aftertriggerInsert on employee_details

FOR INSERT

AS declare @empid int, @empname varchar(60), @empsal decimal(18,0);

select @empid=k.Emp_ID from inserted k;

select @empname=k.Emp_Name from inserted k;

select @empsal=k.Emp_Sal from inserted k;

set @Emp_perform_action='Inserted Record -- After Insert Trigger.'; insert into Employee_performance (Emp_ID,Emp_Name,Emp_Sal,Emp_perform,Time_perform)

values (@empid,@empname,@empsal,@Emp_perform_action,getdate());

PRINT 'AFTER INSERT trigger fired.'

 

Now we will write a query of insert :-

         

insert into Employee_details(Emp_Name,Emp_Sal)values ('Ravindra',3600);

Now we will fetch data  from both table  and output is below----

select * from Employee_details                                                                 

select * from Employee_performance

ii)Use After Update Trigger:-

          Here we will update trigger with the help of sql query we will update some field change in a table:-

v  Create trigger on table Employee_details for Update statement

CREATE TRIGGER aftertriggerUpdate ON dbo.Employee_details

FOR UPDATE

AS

declare @empid int, @empname varchar(60), @empsal decimal(18,0), @Emp_perform varchar(150);

select @empid=k.Emp_ID from inserted k;

select @empname=k.Emp_Name from inserted k;

select @empsal=k.Emp_Sal from inserted k; if update(Emp_Name)

set @Emp_perform=After Update Trigger Emp_details Record.';

if update (Emp_Sal)

set @Emp_details= After Update Trigger Emp_details Record.';

insert intoEmployee_performance(Emp_ID,Emp_Name,Emp_Sal,Emp_perform, Time_perform)

values (@empid,@empname,@empsal,@ Emp_perform,getdate());

PRINT 'AFTER UPDATE trigger fired.'

We will upadte data in Employee_details….

v  update Employee_details set Emp_Name='Give Employee Name' Where Emp_ID =”Give employee id where updte name”;

iii)After Delete Trigger-Here we will learn how to delete trigger use with the help of sql query ,I will delete some record in a table and show a record .

v  Create trigger on table Employee_details for Delete statement

CREATE TRIGGER aftertriggerdelete ON dbo.Employee_details

FOR DELETE

AS

declare @empid int, @empname varchar(60), @empsal decimal(18,0), @audit_action varchar(150); select @empid=e.Emp_ID FROM deleted e;

select @empname=e.Emp_Name from deleted e;

select @empsal=e.Emp_Sal from deleted e;

select @Emp_perform=After Delete Trigger in a employee_details.';

insert into Employee_performance (Emp_ID,Emp_Name,Emp_Sal,Emp_perform, Time_perform)

values (@empid,@empname,@empsal,@ Emp_perform,getdate());

PRINT 'AFTER DELETE TRIGGER fired.'

-We will delete data in Employee_details table….

v  DELETE FROM Employee_details where emp_id = “here give a id which record deleted”

-We will select data from both the tables …

select * from Employee_details

select * from Employee_performance

Instead Of Insert Trigger:-

Here we will write a query Instead of insert trigger statement in sql server

Now create insert trigger before we discuss instead of insert trigger we insert the data in a virtual table prior checking the constraints.

Use of instead of Insert Trigger:-

Now create a new table of customer  For Instead of Insert Trigger..

CREATE TABLE [dbo].[Customer]([Cus_id] CHAR(20) PRIMARY KEY,[Cus_Name] VARCHAR(60)

)

GO

INSERT INTO [dbo].[Customer]  VALUES('001','Mahi')

GO

Now Consider to insert a query in sql database :-

INSERT INTO [dbo].[Customer] (cus_Name) VALUES('Sobhagya')

Here enter the data in the column (name). We will be excecuting NULL values in the column (id). I have a primary key column in the (cus_id) column. There is no any permit for NULL in a primary because primary key constraint is violated.

If we will use of After Trigger so that constraints are proper checkingto insert the data in the table. In case of primary key constraint is violated if you have not put data into virtual table. Data is inserted into the virtual table proper constraint check.

Syntax With Example:-

CREATE TRIGGER INSTEAD_TRIGG ON dbo.Employee_details

INSTEAD OF Insert

AS

declare @@empid int, @empname varchar(55), @empsal decimal(10,2), @emp_perform varchar(150);

select @empid =k.empid  from inserted k;

select @empname=k.empname from inserted k;

select @empsal=k.empsal from inserted k;

SET @emp_perform=' Instead Of Insert Trigger.';

BEGIN 

 BEGIN TRAN

 SET NOCOUNT ON

 if(@emp_sal>=2050)

 begin

 RAISERROR('Cannot Insert where salary < 2050',16,1); ROLLBACK; end

 else begin Insert into Employee_details empname,empsal) values (@empname,@empsal); Insert into Employee_performance (empid,empname,empsal,emp_perform,Time_perform) values(@@identity,@empname,@empsal,@emp_perform,getdate());

 COMMIT;

 PRINT 'Record Inserted -- Instead Of Insert Trigger.'

END

How To create a Repeater and give the Field name?

Here I will explain how to create a repeater .....

Definition of Repeater Control?

Repeater -It is used to display the repeated list of items that is called Repeater.

Here Explain Repeater control and Templates

The Repeater control makes use of the following templates.

Ø  ItemTemplate – It is use this template repeated for each record present in its DataSource.

Ø  SeparatorTemplate – Separator Template add a separator between two items of the Repeater control.

Ø  FooterTemplate – Footer template will not be repeated and will be placed in the bottom most position i.e. footer section of the Repeater control.

Ø  AlternatingItemTemplate – It is used for adding alternate items. It is used along with ItemTemplate.

Ø  HeaderTemplate – Header Content template will not be repeated and will be placed in the top most position (head section of the Repeater control).

 For Example:- 

Create Database 
Database Table Name: Employee_Details
Create New Table -Employee
Table Field Name- ID Int
                                 EmployeeName Varchar(50)
                                 Salary float
Here i am designing repeater in asp.net page.... 

<div>
<asp:Repeater ID="rpt" runat="server">
<HeaderTemplate>
<table >
<tr>
<b>
<td>
ID</td>
<td>
Employee Name
</td>
<td>
Salary
</td>
</b>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr >
<td>
<%#DataBinder.Eval(Container,"DataItem.ID")%>
</td>
<td>
<%#DataBinder.Eval(Container,"DataItem.Employee Name
")%>
</td>
<td>
<%#DataBinder.Eval(Container,"DataItem.Salary")%>
</td>
</tr>
</ItemTemplate>
<SeparatorTemplate>
<tr>
<td>
<hr />
</td>
<td>
<hr />
</td>
<td>
<hr />
</td>
</tr>
</SeparatorTemplate>
<AlternatingItemTemplate>
<tr>
<td>
<%#DataBinder.Eval(Container,"DataItem.ID")%>
</td>
<td>
<%#DataBinder.Eval(Container,"DataItem.EmployeeName")%>
</td>
<td>
<%#DataBinder.Eval(Container,"DataItem.Salary")%>
</td>
</tr>
</AlternatingItemTemplate>
<SeparatorTemplate>
<tr>
<td>
<hr />
</td>
<td>
<hr />
</td>
<td>
<hr />
</td>
</tr>
</SeparatorTemplate>
<FooterTemplate>
<tr>
<td>
Employee Record Display
</td>
</tr>
</table>
</FooterTemplate>
</asp:Repeater>
</div>
</form>
</body>
</html>

Code behind file code

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
SqlConnection con;
SqlCommand cmd = new SqlCommand();
protected void Page_Load(object sender, EventArgs e)
{
con = new SqlConnection(ConfigurationManager.ConnectionStrings["con"].ConnectionString);
cmd.Connection = con;
cmd.CommandText = "select * from Employee";
con.Open();
rpt.DataSource = cmd.ExecuteReader();
rpt.DataBind();
con.Close();
}
}

Now Complete Repeater .....