Checkin situation in login

Question

1.22/5 (2 votes)

See more:

Could you please help me to get a solution for my issue. I am using a SQL Server database and c# i have a gym and i want to chechin my login client with his offer.

offers; 1- by month . 2- by count of days.

my offer table;

| ID | startdate |  month |  day  |  enddate  |      type        |<br />
| 1  | 2019-03-05|   3    | null  |2019-06-05 |Business Calendar |<br />
| 2  | 2019-03-05|  null  |   30  |2019-04-04 |Day Calendar      |

What I have tried:

C#

try
            {



                string che = @"(select count(*)from table where id='" + ID.Text + "' and startdate <='" + DateTime.Now + "' and endDate >='" + DateTime.Now + "' )";
                con.Open();
                SqlCommand sda = new SqlCommand(che, con);
                int count = (int)sda.ExecuteScalar();
                if (count > 0)
                {
                    using (SqlCommand com = new SqlCommand("INSERT INTO [checkin] (ID,time,username) VALUES (@ID,@time,@username)", con))
                    {
                        com.Parameters.AddWithValue("@ID", ID.Text);

                        com.Parameters.AddWithValue("@time", txttime.Text);

                        com.Parameters.AddWithValue("@username", txtusername.Text);
                        com.ExecuteNonQuery();
                    }
                    MetroFramework.MetroMessageBox.Show(this, "Check In Sucssesfuly ................... ", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                else
                {
                    MetroFramework.MetroMessageBox.Show(this, "this ID Expired .....................", "Message", MessageBoxButtons.OK, MessageBoxIcon.Warning);


                }
                con.Close();
            }

            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally
            {
                if (con.State == ConnectionState.Open)
                    con.Close();
            }

what i'm looking for is add something to this code if it day calendar count days not check the end date to expired the ID

Posted 16-Mar-19 21:32pm

el_tot93

Updated 16-Mar-19 21:46pm

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2019-03-16T21:46:00

Don't do it like that! Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.

When you concatenate strings, you cause problems because SQL receives commands like:

SQL

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:

SQL

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

Which SQL sees as three separate commands:

SQL

SELECT * FROM MyTable WHERE StreetAddress = 'x';

A perfectly valid SELECT

SQL

DROP TABLE MyTable;

A perfectly valid "delete the table" command

SQL

--'

And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.

So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?