SQL Server Stored Procedure Email verification - sql-server-2008

Question

I have an ASP.net that requests client's information from stored procedure in SQL Server 2008 based on a client's email address until the # sign. Since the clients often change after 3 months in this small organization, but the email addresses remain the same.
E.g. a client with email address obois_in4#cegepoutaouais.qc.ca finishes his/her contract after 3-4 months and then that email address is assigned to someone else.
Now, here's my question: I want my stored procedure to find the client information, after he/she entered obois_in4 and presses the Search button. The reason I don't want them to enter the whole email is because it's too long, and secondly they can make a mistake while typing, but typing such as obois_in4 isn't a big deal.
I wrote a code that can search a client by name, but again, the clients always change after 3-4 months but the email address remains the same.
ALTER PROCEDURE [dbo].[sp_find_client_information]
-- Add the parameters for the stored procedure here
#client_email varchar (50) = null
AS Declare #numOfRows int BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
-- Insert statements for procedure here
SELECT #numOfRows = COUNT (*)
From helpdesk_clients
Where --change first name and
client_firstName = #client_email or client_lastName = #client_email;
begin
if (#numOfRows = 0)
select #numOfRows;
else if (#numOfRows = 1)
select
client_id,
client_firstName,
client_lastName,
client_work_email,
client_work_phone,
client_work_phone_ext,
client_office,
dept_nom,
client_position
from
helpdesk_clients join departments
on
helpdesk_clients.dept_id = departments.dept_id
where client_firstName like '%'+#client_email+'%';
end
END
The email address always starts with obois followed by an underscore _ then the name of the department information technology as in and then by a digit such as 4 in this case. e.g. obois_in4#cegepoutaouais.qc.ca

Answer 1

I am surprised nobody even bothered looking into this. The best solution is to use Substring() and CharIndex()
With SUBSTRING ( expression ,start , length ) we can truncate the string starting from a position within the string until a specified position within a string. With CHARINDEX ( expressionToFind ,expressionToSearch [ , start_location ] ), we can find the the position of a character within a given string.
substring (work_email, 1, CHARINDEX('#', work_email)-1) = #work_email ensures that a parameter doesn't have to be like shawn.smith#cegepoutaouais.qc.ca, and it's a big hassle for a client to enter his full email like shawn.smith#cegepoutaouais.qc.ca, he will only be required to enter shwan.smith, the script will search for shawn.smith in shawn.smith#cegepoutaouais.qc.ca until the # sign.
e.g.
In the stored procedure, assuming the #work_email is parameter and it's value is 'shawn.smith'
select
client_id,
client_firstName,
client_lastName,
client_work_email,
client_work_phone,
client_work_phone_ext,
client_office,
dept_nom,
client_position
from
helpdesk_clients join departments
on
helpdesk_clients.dept_id = departments.dept_id
where substring (work_email, 1, CHARINDEX('#', work_email)-1) = #work_email;
Will return the all the details mentioned in the Select statement.