I want to copy data from 2 tables to another.

Question

1.00/5 (2 votes)

See more:

Hi guys,

I want to Copy data from two tables and insert it into another table without any duplicate Values.

When I tried the below code, Only the first row is inserting.

What I have tried:

qr = "select emp_code,punch_time,MemberID,MemberName,EndDate from iclock_transaction JOIN Gym_Membership ON (emp_code=MemberID)  ORDER by punch_time  "
        ds = SearchData(qr)
        Dim ID As String
        Dim Count As String
        Dim Days As String
        Dim j As Integer

        Dim MemberID As String
        Dim MemberName As String
        DashBoard.RichTextBox2.Clear()
        DashBoard.PictureBox5.Image = Nothing

        Count = ds.Tables(0).Rows.Count
        DashBoard.Label14.Text = Count

        Try

            For i = 0 To ds.Tables(0).Rows.Count - 1
                Days = DateDiff(DateInterval.Day, Today.Date, ds.Tables(0).Rows(i)("EndDate"))
                MemberID = ds.Tables(0).Rows(i)("MemberID")
                MemberName = ds.Tables(0).Rows(i)("MemberName")
                DashBoard.Label13.Text = Days


                qr = "Select * from Gym_Attendence where ID ='" & MemberID & "' "
                ds = SearchData(qr)

                If ds.Tables(0).Rows.Count > 0 Then
                Else

                    qr = "Insert into Gym_Attendence values('" & MemberID & "','" & MemberName & "','" & Now.ToString("MM/dd/yyyy HH:mm:ss") & "')"
                    Dim logincorrect As Boolean = Convert.ToBoolean(InsertData(qr))

                End If

            Next

        Catch
        End Try

Posted 1-Feb-23 1:11am

zakariyaptpl

Updated 2-Feb-23 1:02am

v3

Add a Solution

Comments

Richard Deeming 1-Feb-23 7:22am

Well, fix it so that it is working then.

Seriously, "not working" tells us precisely nothing. You need to click the green "Improve question" link and update your question to include a clear and precise description of the problem, including the full details of any errors, full details of what you have tried and where you are stuck.

Richard Deeming 1-Feb-23 7:22am

Also, your code is vulnerable to SQL Injection[^]. NEVER use string concatenation/interpolation to build a SQL query. ALWAYS use a parameterized query.

Everything you wanted to know about SQL injection (but were afraid to ask) | Troy Hunt[^]
How can I explain SQL injection without technical jargon? | Information Security Stack Exchange[^]
Query Parameterization Cheat Sheet | OWASP[^]

2 solutions

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 · 2023-02-01T03:05:00

AS Richard has said, 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?

Doing that through your whole app may fix the problem as well, but if it doesn;t then move to the next serious mistake you are making: exception swallowing.

Your code does this:

VB

Try

    For i = 0 To ds.Tables(0).Rows.Count - 1
         ...
    Next

Catch
End Try

So if anything goes wrong inside the loop, you throw away any error information and exit. That means that you don't know what went wrong, and have no way to find out!
That's called "Swallowing an Exception" and it's easy to fix: Use Catch with an exception parameter. Try...Catch...Finally statement - Visual Basic | Microsoft Learn[^] shows you how.
Now run your code in the debugger and if any exception occurs you can look at the details in the Catch block by putting a breakpoint on it. Those will tell you what happened, and where - which is the first part of trying to fix it!

Tanzila Sadika · Answer 2 · 2023-02-02T01:02:00

Check if the InsertData method is executing correctly and returning a boolean value as expected.
Use a different approach to insert the data into the Gym_Attendence table. For example, you could use a DataAdapter and DataSet to insert the data into the table and avoid any duplicates.

qr = "select emp_code,punch_time,MemberID,MemberName,EndDate from iclock_transaction JOIN Gym_Membership ON (emp_code=MemberID)  ORDER by punch_time  "
ds = SearchData(qr)
Dim ID As String
Dim Count As String
Dim Days As String
Dim j As Integer

Dim MemberID As String
Dim MemberName As String
DashBoard.RichTextBox2.Clear()
DashBoard.PictureBox5.Image = Nothing

Count = ds.Tables(0).Rows.Count
DashBoard

I want to copy data from 2 tables to another.

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0