Check Exist or not

 String qryChkExist = "SELECT isnull(column_name,'') as Article_alias from Table_Name where column_name='" + txtalias.text.tostring().trim()+ "'";

 String ChkRecord = (String)SqlHelper.ExecuteScalar(ConnectionString, CommandType.Text, qryChkExist);
        if (ChkRecord != null)
        {
            if (ChkRecord != "")
            {
                lblMsg.Text = "Another Alias with this Name already exists. Please choose another Alias.";
                return;
            }
        }

Limitation Login

Step 1:Use NameSpaces As

using System.Data.SqlClient;


Step 2: Global Declaration Are:

SqlConnection con = new SqlConnection("Ur Connection");


Step 3:Page_Load

protected void Page_Load(object sender, EventArgs e)
{

if (!Page.IsPostBack)
{
this.ViewState["count"] = 0;
}


}

Step 4:write a Method

public void m()
{
string user = "";
string pass = "";
string str = "select * from tbl_Login where username='" + TextBox1.Text + "' and password='" + TextBox2.Text + "'";
//string count = "";
con.Open();
SqlCommand cmd = new SqlCommand(str, con);
cmd.CommandType = CommandType.Text;
SqlDataReader dr;
dr = cmd.ExecuteReader();
while (dr.Read() == true)
{
user = dr[1].ToString();
pass = dr[2].ToString();


}


dr.Close();
if (TextBox1.Text == user && TextBox2.Text == pass)
{
Response.Redirect("Default2.aspx");
}
else
{
Label1.Text = "Login Failed";
}
con.Close();


Step 5: On Button Click

protected void Button1_Click(object sender, EventArgs e)
{
int i = Convert.ToInt32 (this.ViewState["count"].ToString())+1;
//int i = this.ViewState["count"] + 1;

this.ViewState["count"]=i;
if (i <=3)
{


m();



}
else
{
Label1.Text = "Please Contact Admin.. YOuR Login Limit Exceed";
}
}

except keyword in sql server

CREATE TABLE EMP  (ID INTEGER NOT NULL,NAME VARCHAR(20) NOT NULL, CITY   VARCHAR(20) NULL)                    
                       

insert into EMP values(1,  'EMP1', 'DELHI')
insert into EMP values(2,  'EMP2', 'CHENNAI')
insert into EMP values(3,  'EMP3', 'PUNE')
insert into EMP values(4,  'EMP4', 'AGRA')
insert into EMP values(5,  'EMP5', 'CHENNAI')

CREATE TABLE CITY(ID INT IDENTITY, CITY_NAME VARCHAR(20))

insert into CITY values('CHENNAI')
SELECT CITY FROM EMP EXCEPT SELECT CITY_NAME FROM CITY

insert record in two table

create table Person

(

p_id int IDENTITY(1,1) not null primary key,

Fname varchar(50),

Lname varchar(50),

address varchar(50)

)

go



create table orders

(

o_id int IDENTITY(1,1) not null primary key,

oname varchar(50),

Qty int,

p_id int foreign key references Person(p_id),

prize Int

)

go



Create Proc Usp_Orders_Insert

(

@Param_Fname Varchar(50),

@Param_Lname Varchar(50),

@Param_Address Varchar(50),

@Param_oname Varchar(50),

@Param_Qty  Int,

@Param_prize Int

)

As

Begin

 Set Nocount On

 

 Declare @PersonID Int

 

 Begin Try

  Begin Tran 

   

  Insert Person(Fname, Lname, [address]) Values(@Param_Fname, @Param_Lname, @Param_Address)

  Select @PersonID = @@Identity 

 

  Insert orders(oname, Qty, p_id, prize) Values(@Param_oname, @Param_Qty, @PersonID, @Param_prize)

  

  Commit

   

 End Try

 Begin Catch

  Declare @Message Varchar(Max)

  Select @Message = 'Error : ' + ERROR_MESSAGE() + CHAR(10) + 'Line No: '+ Cast(ERROR_LINE() as Varchar(10))

  Raiserror(@Message,16,1)

  Rollback  

 End Catch

End

Go