How to check if value exists in database,

Question

3.50/5 (4 votes)

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Hi all,

I have a text box in a windows form. My question is, how to check existing text which is entered in text box through database? Please reply me with an example.

Posted 17-Jan-11 4:43am

ks ravi

Updated 17-Jan-11 4:47am

JF2015

v2

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Comments

Ravi Sant 17-Jan-11 10:49am

By this do u mean -
You can easily get txtBox.Text anytime to check data in it.
can you rephrase your question clearly please with few code lines?

OriginalGriff 17-Jan-11 12:15pm

PLease do not post replies to answers using the "Add and Answer" feature: instead use the "Add Comment" at teh bottom right of each answer. That way the appropriate person gets an email to say you have more to say. With an answer, they don't, so they do not find out unless they revisit your question. I have moved your answer to a comment, and deleted the answer.

MeftahDAKHEEL 29-Mar-15 12:20pm

i need to have a help with my code, i need to check if value exists in database and show a message...
=============================
my code
=============
private void btnSearch_Click(object sender, EventArgs e)
{

if (searchtext.Text == "")
{
MessageBox.Show("Plese Inter Employee's ID you are searching for");
searchtext.Focus();
}
else
{

OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\\Employees.mdb");
OleDbDataAdapter ad = new OleDbDataAdapter("select * from Employee where EmpID=@EmpID", con);
ad.SelectCommand.Parameters.Add("@EmpID", OleDbType.Integer);
ad.SelectCommand.Parameters["@EmpID"].Value = int.Parse(searchtext.Text);

DataSet ds = new DataSet();
ad.Fill(ds, "Emp");
DGV1.DataSource = ds.Tables["Emp"];

if (ds == null)
{

MessageBox.Show("not found!!");

}
else
{
MessageBox.Show("The Employee you are searching for is listed down, if you want to update the data click the arrow sign on the lift side of the record");
}
}

5 solutions

Solution 5

hi,

CREATE PROCEDURE Procedure_Name
@mystring varchar(100),
@isExist bit out
AS
BEGIN
	if exists(select column1 from tblTable1 where column1=@mystring)
	begin
	select @isExist=1
	end
	else
	begin
	select @isExist=0
	end
	
	
END
GO

then write the method to check whether the value exist or not
thatis if @isExist=1 that means the value exist.otherwise not..
Hope this may help you..

Posted 18-Jan-11 1:28am

Blesson Mathew

Solution 6

If(exists(select * from table where column=@clounm))
Begin
Selct 'true'
END
ELSE
BEGIN
select 'false'
END

Posted 18-Jan-11 1:30am

dharmesh15

Solution 3

You can read about Count() function in sql here.http://www.w3schools.com/sql/sql_func_count.asp[^].You write the appropriate query to find the count from your table with value in textbox as condition in "where" of sql.if count is greater than 0,it means record is existing,else you can proceed with insertion as a new value.

Posted 17-Jan-11 5:32am

Anupama Roy

Updated 17-Jan-11 5:33am

v2

Comments

RaviRanjanKr 18-Jan-11 0:42am

My vote of 5!
there is nothing wrong in your answer.
I think OP and others haven't notice about what Count() can do.
This http://www.c-sharpcorner.com/forums/ShowMessages.aspx?ThreadID=81120 link has some best answer for same question which is using Count() function.

Anupama Roy 18-Jan-11 0:51am

Thank You!

Blesson Mathew 18-Jan-11 7:29am

Your answer is a good one..So I am giving you 5+

Solution 1

Retrieve the text, send it to a stored proc, and let the stored proc search the applicable column for the text.

Posted 17-Jan-11 4:47am

#realJSOP

Comments

OriginalGriff 17-Jan-11 12:12pm

The OP Wrote:
"please send me an example boz i'm new to this"

Yusuf 17-Jan-11 14:18pm

The new reply to comment feature is Cool! Sorry to hijack your comment @OriginalGriff, can't resist the temptations.

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Shahin Khorshidnia · Accepted Answer · 2011-01-17T07:20:00

Hi,
Make a stored procedure in SQL Server for example:

Create	Procedure	FindString(<br />
@MyString	nvarchar(50))<br />
As<br />
Begin<br />
		Select	*	From	MyTable<br />
					Where		Value = @MyString<br />
End

Make a Class in .NET For example :

public class ReadData
{
    public bool FindString(string myString)
    {
        SqlConnection connection = new SqlConnection();
        connection.ConnectionString = "Server=..."; //Your connection string
        SqlCommand command = new SqlCommand();
        command.Connection = connection;
        command.CommandType = CommandType.StoredProcedure;
        command.CommandText = "FindString";
        command.Parameters.AddWithValue("@MyString", myString);
        try
        {
            connection.Open();
            SqlDataReader reader = command.ExecuteReader();
            while (reader.Read())
            {
                return true;
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
        finally
        {
            if (connection.State == ConnectionState.Open)
                connection.Close();
        }                
        return false;
    }
}

Use the class. for example :

C#

ReadData r = new ReadData();

if (r.FindString("Shahingg"))
    MessageBox.Show("I Found it!");
else
    MessageBox.Show("I can't Find it!");

Do not forget that you need below namespaces for your Class :

C#

using System.Data.SqlClient;
using System.Data;

Good Luck

How to check if value exists in database,

5 solutions

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