Re: Problem at inserting a DB entry - C# Discussion Boards

Re: Formatting a number and digits of precision

7-Nov-18 6:28

Not really - The C version depends on the compiler. If I try with an online C compiler[^] I get:

0.123456789012345                                                                                                                                            
12345.123456789011470

If I try with Virtual-C[^] I get this:

0.123456789012345
12345.123456789011135

IT's not "extra accurate digits" it's "different interpretation of the output". Because floating point numbers don't translate well into binary (for example, 0.2 in decimal is a fixed value, in binary is a repeating sequence so it isn't accurate) you can "generate" more digits if you take the first one, then multiple by 10.0 and repeat. That doesn't mean that the values to get are "more accurate" - in fact they are prone to reduced accuracy but a higher digit count. Try it again with some different numbers and you should see what I mean.

Generally speaking, all systems use the same floating point storage design: IEEE 754, (because if they don't they can't use floating point coprocessors to do the hard stuff!)
IEEE 754 - Wikipedia[^]

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csharpsucks7-Nov-18 6:44

csharpsucks

7-Nov-18 6:44

I've punted on this issue it will be interesting to see the results of the data analysis when I load this data back into the system and process against the original data. I'm dealing with nanometer measurement data.

Thanks for the help.

Problem at inserting a DB entry

User 136751145-Nov-18 23:49

User 13675114

5-Nov-18 23:49

Hi Guys,

Below code don't allow to create entry at database with null areas and pop-up comes to warn user.

I fill all fields/create entry and all fields are cleared up for new entry but once I try to add new entry, program allows me to create with empty fields.

Do I need to add some code in order form to reload or something like that?

What would be the way of getting rid of this issue?

Thanks.

note: something other than Application.Restart(). that would be great if no close&open app.

private void btnStokEkle_Click_1(object sender, EventArgs e)
        {
            if (txtAdi.Text == "" || txtModel.Text == "" || txtSeriNo.Text == "" || gon.Text == "" || tah.Text == "")
            {
                MessageBox.Show("Lütfen Tüm Alanları Doldurunuz.", "Hata", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            else

            vt.sqlCalistir("insert into kolon (siparis,malzeme,takip,gonder,tahmini,gercek) values ('" + txtAdi.Text + "','" + txtModel.Text + "','" + txtSeriNo.Text + "','" + gon.Text + "','" + tah.Text + "', '" + tt.Text + "')");
            MessageBox.Show("İşlem Kaydı Yapıldı.", "İşlem Tamam", MessageBoxButtons.OK, MessageBoxIcon.Information);

            getir();
            txtId.Clear();
            txtAdi.Clear();
            txtModel.Clear();
            txtSeriNo.Clear();
            gon.EditValue = " ";
            tah.EditValue = " ";
            tt.EditValue = " ";
            txtSeriNo.Text = Environment.UserName;

        }

modified 13-Feb-19 21:02pm.

OriginalGriff6-Nov-18 0:08

6-Nov-18 0:08

Not 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?

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User 136751146-Nov-18 3:12

User 13675114

6-Nov-18 3:12

Well noted OriginalGriff. As a C# beginner, I was trying to practice basic CRUD in Access db and yes backup is on.

I am just stuck at solving this. so is it all about SQL commands? if I use correct commands then that click event won't save any entry with a null field?

modified 13-Feb-19 21:02pm.

Luc Pattyn6-Nov-18 3:51

Luc Pattyn

6-Nov-18 3:51

What null field? A TextBox never contains null, if it is empty, then its .Text property returns the empty string, not null.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

tranthanhtu.vn6-Nov-18 18:12

6-Nov-18 18:12

Hi Al Soyo,
This was interesting, Please ping me on skype (tranthanhtu83) if you still not solve this issue.

Best regards,
TU Tran
Technical Leader
Blog: http://tranthanhtu.vn
Mail: contact@tranthanhtu.vn
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Richard Deeming7-Nov-18 0:59

Richard Deeming

7-Nov-18 0:59

You've been here long enough to know that this is NOT how CodeProject works.

If you want to help someone, then help them here on the site, so that others who are having the same problem can see the discussion and benefit from it.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

tranthanhtu.vn7-Nov-18 1:27

7-Nov-18 1:27

Hi Richard Deeming,
I intend to check the code and will write another comment for the root cause.
Just look at the code, seems not create such problem.

And I will appreciate if you can talk in more friendly way (such as: this will violate the rule, .....).
We are here to learn and share friend and you are not my boss.

Thanks

Richard Deeming7-Nov-18 1:32

Richard Deeming

7-Nov-18 1:32

Trying to take the discussion off-line violates the rules of this site.

If you want to help people on CodeProject, then help them HERE, not in a Skype discussion.

You've been here over 11 years. That's more than long enough to know the rules!

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

tranthanhtu.vn7-Nov-18 1:36

7-Nov-18 1:36

Thank Richard Deeming,

Eddy Vluggen7-Nov-18 1:44

Eddy Vluggen

7-Nov-18 1:44

Since I'm not your boss, I need not stay friendly. There is nothing "interesting" about his "issue", and it seems like spamming. Going for a coffee before I decide whether or not to report this as spam, since your post does not contribute anything.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

tranthanhtu.vn7-Nov-18 2:29

7-Nov-18 2:29

Thank Eddy Vluggen for letting me know your idea.
Yeah, it was up to you.
Let consider the situation, @Eddy Vluggen has a problem with his code and the code seems works fine.
The problem was still there, I intend to ask him and may run the code to see any potential cause raises this problem, and may help him to fix. of course, I can write another comment about the root cause if I can found.
And I was not allowed and may be reported as spammer just because someone did not see what I see: The code looks ok but not work.
@Eddy Vluggen: Do you think this is the interesting point.

Again, thank for let me know your idea and you can do what ever you think is right.

Eddy Vluggen7-Nov-18 2:37

Eddy Vluggen

7-Nov-18 2:37

tranthanhtu.vn wrote:
And I was not allowed and may be reported as spammer just because someone did not see what I see: The code looks ok but not work.

The code does not look "ok".

It is also not a particular complicated subject, there's literally examples on MSDN that you can copy and paste.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

tranthanhtu.vn7-Nov-18 2:42

Correlation of several multi-track charts in C#

7-Nov-18 2:42

Thank Eddy Vluggen,
Oh, I may lack of knowledge about "Win Application".
Ok, will come back and see the root cause and learn.

Member 133258465-Nov-18 19:13

Member 13325846

5-Nov-18 19:13

Hi,
How can i perform correlation on several charts(Draw lines to connect specific digits (e.g. depth or height) of a specific track on several multi-track charts) and print it in my report. on the another word, i want to connect related or same parts of all tracks together. for example imagine a hill that you dig(drill) a hole on that and dig(drill) another one beside it on a plane surface. the depth for both of holes is 1000m, the height of the hill is 5m. the lithology (Rock or Ore type) for both holes will be the same for 95m and there will be 5m difference between their lithology changes. i want to connect related parts together. i am also using from DevExpress components. if there are methods to achieve this, with DevExpress components or the visual studio itself, i will be thankful to help me or guide me through some useful assays. another question is how can i attach an image to my question.
thank you in advance.

[solved] GuidAttribute

Super Lloyd5-Nov-18 2:29

Super Lloyd

5-Nov-18 2:29

For my serializer I have a table of all types from all loaded assembly that have an GuidAttribute.

Today, for debugging / diagnostic purpose, I decided to Log whenever a duplicate was found

Imagine my surprise when I found out zillion of duplicates! Mostly what looks like C++/RT COM interface.. behold!

(000214F2-0000-0000-C000-000000000046, ): Standard.IEnumIDList, Standard.IEnumIDList
(2c1c7e2e-2d0e-4059-831e-1e6f82335c2e, ): Standard.IEnumObjects, Standard.IEnumObjects
(92CA9DCD-5622-4bba-A805-5E9F541BD8C9, ): Standard.IObjectArray, Standard.IObjectArray
(92CA9DCD-5622-4bba-A805-5E9F541BD8C9, ): Standard.IObjectArray, Standard.IObjectCollection
(886d8eeb-8cf2-4446-8d02-cdba1dbdcf99, ): Standard.IPropertyStore, Standard.IPropertyStore
(000214E6-0000-0000-C000-000000000046, ): Standard.IShellFolder, Standard.IShellFolder
(43826d1e-e718-42ee-bc55-a1e261c37bfe, ): Standard.IShellItem, Standard.IShellItem
(B63EA76D-1F85-456F-A19C-48159EFA858B, ): Standard.IShellItemArray, Standard.IShellItemArray
(7e9fb0d3-919f-4307-ab2e-9b1860310c93, ): Standard.IShellItem2, Standard.IShellItem2
(000214F9-0000-0000-C000-000000000046, ): Standard.IShellLinkW, Standard.IShellLinkW
(56FDF342-FD6D-11d0-958A-006097C9A090, ): Standard.ITaskbarList, Standard.ITaskbarList
(602D4995-B13A-429b-A66E-1935E44F4317, ): Standard.ITaskbarList2, Standard.ITaskbarList2
(12337d35-94c6-48a0-bce7-6a9c69d4d600, ): Standard.IApplicationDestinations, Standard.IApplicationDestinations
(3c594f9f-9f30-47a1-979a-c9e83d3d0a06, ): Standard.IApplicationDocumentLists, Standard.IApplicationDocumentLists
(6332debf-87b5-4670-90c0-5e57b408a49e, ): Standard.ICustomDestinationList, Standard.ICustomDestinationList
(36db0196-9665-46d1-9ba7-d3709eecf9ed, ): Standard.IObjectWithAppUserModelId, Standard.IObjectWithAppUserModelId
(71e806fb-8dee-46fc-bf8c-7748a8a1ae13, ): Standard.IObjectWithProgId, Standard.IObjectWithProgId
(ea1afb91-9e28-4b86-90e9-9e9f8a5eefaf, ): Standard.ITaskbarList3, Standard.ITaskbarList3
(ea1afb91-9e28-4b86-90e9-9e9f8a5eefaf, ): Standard.ITaskbarList3, Standard.ITaskbarList4

What kind of criteria could I apply to skip such a type?
I don't foresee any would be used by the application, but if I could find some criteria that automatically dismiss such type and warn when they are used it would be nice... but I am not sure what to use...

mmm.. me think I could use (new) MyGuidAttribute instead of GuidAttribute. but it's kind of a hassle...

[EDIT]
I skipped all type where type.IsCOMObject || type.IsImport and I am down to 8 duplicates! Big Grin | :-D

(496B0ABE-CDEE-11d3-88E8-00902754C43A, ): System.Collections.IEnumerable, System.Runtime.InteropServices.UCOMIEnumerable
(496B0ABF-CDEE-11d3-88E8-00902754C43A, ): System.Collections.IEnumerator, System.Runtime.InteropServices.UCOMIEnumerator
(AFBF15E5-C37C-11d2-B88E-00A0C9B471B8, ): System.Reflection.IReflect, System.Runtime.InteropServices.UCOMIReflect
(AFBF15E6-C37C-11d2-B88E-00A0C9B471B8, ): System.Runtime.InteropServices.UCOMIExpando, System.Runtime.InteropServices.Expando.IExpando
(496B0ABE-CDEE-11d3-88E8-00902754C43A, ): System.Collections.IEnumerable, System.Runtime.InteropServices.ComTypes.IEnumerable
(496B0ABF-CDEE-11d3-88E8-00902754C43A, ): System.Collections.IEnumerator, System.Runtime.InteropServices.ComTypes.IEnumerator
(AFBF15E6-C37C-11d2-B88E-00A0C9B471B8, ): System.Runtime.InteropServices.UCOMIExpando, System.Runtime.InteropServices.ComTypes.IExpando
(AFBF15E5-C37C-11d2-B88E-00A0C9B471B8, ): System.Reflection.IReflect, System.Runtime.InteropServices.ComTypes.IReflect

Mm.. that might be acceptable... although there is the risk of skipping IEnumerable instead of UCOMIEnumerable... Cry | :((

[EDIT2, solved]
I skipped all types where type.IsCOMObject || type.IsImport || type.Namespace.StartsWith("System.Runtime.InteropServices")

And I have no more duplicates Smile | :)

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modified 5-Nov-18 8:49am.

Creating & writing to a text file from two different forms

Member 140427683-Nov-18 9:45

Member 14042768

3-Nov-18 9:45

Hi,

I've created a code, which creates and writes all inputs to a text file. I have now created a radiobutton function in form1 which creates a new form (form2), in the same namespace. But now i need to print all user input from form2 to print to the same text file created upon clicking the finish button located on form1. Is there anyway to create code in form1 code to print input from form2 textboxes? I just can't find anywhere how to do this, any help would be great. Thanks.
F.d

Re: Creating & writing to a text file from two different forms

Dave Kreskowiak3-Nov-18 10:06

Dave Kreskowiak

3-Nov-18 10:06

It appears the problem isn't with writing to a file, but getting the data from another form.

There's many different ways of doing this. The easiest would be to write a public, property on your 2nd form that just returns the text from a textbox. You can then write that data to your file from your 1st form.

public string SomePropertyName
{
    get
    {
        return SomeTextBox.Text;
    }
}

Asking questions is a skill
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Seriously, go read these articles.

Dave Kreskowiak

Re: Creating & writing to a text file from two different forms

Member 140427684-Nov-18 4:03

Member 14042768

4-Nov-18 4:03

Hi,

Thanks for your help.

After looking at this method of coding, I think it might just be easier to place all my data input boxes in the same form. As recalling the data from child to the parent form, seems like going in a large circle for the same end result. I will just work on my visibility options for the textboxes for user inputs.

F.D

Re: Creating & writing to a text file from two different forms

Eddy Vluggen4-Nov-18 4:15

Eddy Vluggen

4-Nov-18 4:15

wrote:
I think it might just be easier to place all my data input boxes in the same form.

Easier, yes. Correct, no.

wrote:
seems like going in a large circle for the same end result

WinForms have an expected behaviour with the end-user. Yes, it is easier to put all in one form; it is even easier to put all the input in Console.ReadLine-form and to not use Forms anyway.

Read the materials provided, it is not that complicated Thumbs Up | :thumbsup:

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

Re: Creating & writing to a text file from two different forms

OriginalGriff4-Nov-18 6:34

Re: Creating & writing to a text file from two different forms

4-Nov-18 6:34

Following that logic, you will also have to add all the controls for the Save dialog, the Open dialog, maybe the Font Select dialog to each of your forms, which might make it rather hard to use!

It's not complicated to do it properly - it's less work that fitting all those controls nicely into your main form - and it means that your new form can be reused.

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Richard MacCutchan3-Nov-18 10:07

Richard MacCutchan

3-Nov-18 10:07

Assuming that Form2 is created from within Form1, then Form2 could provide a method that Form1 calls to get the data, or Form1 passes the reference to the writer. Without more information it is difficult to guess what is best.

Re: Creating & writing to a text file from two different forms

OriginalGriff3-Nov-18 20:28