How To Use If exists in c#

Create your stored procedure as so (but format the indentation as you'd like):

Create Procedure AddCustomer
	@name varchar(50),
	@address varchar(50),
	@phone varchar(50),
	@date datetime
as
begin
  Set NoCount On
	Declare 
			@CustExists 				Int

	Set @CustExists = 0 -- False
	if (exists(select cphone from Customer where cphone=@phone))
	  Set @CustExists = 1
		
	if @CustExists = 0 
		insert into Customer (cname,cadress,cphone,cdate) 
		values (@name,@address,@phone,@date)
		
	return(@CustExists)
end

Then you can execute the proc from your C# code, examining the return code.
Alternatively, you could also use an output parameter instead of the return code, and check that after calling the proc.

Does that work for you?

Hope that helps.

Richard

I think it is better to check the condition from the front-end. Stop the user there itself.

Use Dataset

Count rows, if it is > 0 then give your Message as "Data Already exists."
Else Write your Insert query OR CAll Procedure for Inserting Data.

You can achieve this using output parameter in Stored procedures...

Example below..

create proc AddCustomer
@name varchar(50),
@address varchar(50),
@phone varchar(50),
@date datetime,
@output varchar(50) output // output variable
as
begin
if (exists(select cphone from Customer where cphone=@phone))
begin
   /*print 'This Data exist'*/
   set @output='This Data exist'
End
else
begin
insert into Customer (cname,cadress,cphone,cdate) 
values (@name,@address,@phone,@date)
end
end

c# code below..

        // input parameters...

        SqlParameter message = new SqlParameter("@output",SqlDbType.VarChar,50);// output parameter
        message.Direction = ParameterDirection.Output;
        cmd.Parameters.Add(message);
        cmd.ExecuteNonQuery();
ScriptManager.RegisterStartupScript(this.Page, this.GetType(), "tmp", "<script type='text/javascript'>alert('" +message.value.ToString() +"');</script>", false);

Hope it helps..