QT will QSqlQuery::lastQuery() still show placeholder after addBindValue() being run? - qt

I got "Wrong key or corrupt data" error when executing a query in my code, so I inserted a debug line before the execution of the query to see what it looks like. I used QSqlQuery::lastQuery() to get the query text.
The query looked fine except the WHERE clause:
SELECT ... FROM patient WHERE "idx" = ?
And the debug line happened right after QSqlQuery::addBindValue() was executed to replace the placeholder ? with the real idx value.
I suspect addBindValue() somehow didn't work but I want to be sure. Is it possible lastQuery() still returns the query with placeholder in place even though addBindValue() has been run?

Related

Qt 6 crash in QPlainText::setExtraSelections after QPlainText::setDocument

I'm trying to set up a text widget that highlights the searched word, when I open a new file with QPlainText::setDocument, then immediately use QPlainText::setExtraSelections I get a SIGSEV crash in:
QTextDocumentPrivate::rootFrame
QTextDocumentPrivate::frameAt
QTextCursorPrivate::complexSelectionTable
QTextCursor::hasComplexSelection
QWidgetTextControl::selectionRect
QWidgetTextControl::setExtraSelections
QTextDocumentPrivate is causing a SIGSEV because it is a null this pointer. But this doesn't happen if no word is set before the document is loaded.
I must be supposed to do something to force it to generate the QTextDocumentPrivate. But I have no idea what that is.
Actually, this happens because QPlainText::setDocument does not remove the prior results of QPlainText::setExtraSelections. So when setting the new selections tries to remove the previous things selected, they all have invalid pointers and that causes the crash.
To fix it call: textEdit->setExtraSelections({}); to clear out the selections prior to calling QPlainText::setDocument.

Stack Trace Error for RefTableId field assignment

I created a new table and added a new Integer field (called RefTableId) with an EDT of the standard RefTableId type. Writing NewTable.RefTableId = tableNum(SomeTable); compiles but during run time I get this stack trace error: "Error executing code: Wrong argument types in variable assignment."
I've even tried NewTable.RefTableId = 0; This still fails. And yes, I've triple checked that it is indeed an integer field.
The solution is really stupid, the line before the assignments was reading .data() out of a FormListItem object that had invalid data in it. Instead of showing an error for that line, it skips over it and fails the assignment lines below. It makes no sense to me since I wasn't using any information from that FormListItem object to populate any field data with, yet still caused that to fail for some reason. I'm going to mark this one in the "Bang Head Here" category.
If the code is in a class, be sure to do a compile of all super classes as well as a compile forward (child classes). Remember to do an incremental CIL.
If it still fails do a full compile (axbuild).

ASP.Net: How do I find this error?

I'm getting the following error when I try to run an ASP.Net page. It just popped up during development, and I don't know what the cause is.
"OverflowException Occurred. Value was either too large or too small for an Int32."
The line the debugger breaks on is of absolutely no help at all
Dim ApproxDate As TextBox = FormView1.FindControl("CurrentResultDateTextBox")
The error is occurring on this line because calling findControl on FormView1 causes it to databind (executes a SQL query to return the dataset). I assume the error lies somewhere in one of the object data sources or possibly one of the grid views on the page, but the debugger won't tell me where. Most of the page data sources are bound declaratively (specified in ASP tags in the source)
Pressing F11 to run past the exception displays the following:
"13712696100373320501120906 is not a valid value for Int32."
The value being shown here is the primary key for the main SQL table used by the page. There are about 10 data sources which use this field. Again, there's no indication of where exactly the error is occurring.
So how can I debug an error like this? Are there commands I can run? IIS error logs? 3rd party software to capture the error? I'll take anything I can get
Managed to find the problem. The trick is to first disable "just my code" in the IDE/Debug settings. Then you can see the system functions on the call stack, and while there is no source code, you can click on these functions to unwind the stack to one of the web controls (in this case the ListControl.PerformSelect function)
If you check the auto variables in the debug window, it will show the control involved in the error. From there I added a watch on the ID property to see which control it was, looked up the data source that feeds it, and found the error.
You can also unwind the stack to the ObjectDataSourceView, look at the dataTable property, and call GetErrors() to see the issues. This returns an array of data rows which are flagging errors; The property RowError will show the error message for any given row.

SqlSiteMapProvider - OnSiteMapChanged event never fires?

I'm doing the Wicked Code implementation of SqlSiteMapProvider, except in VB.NET.
There's a few things with the code that are causing issues, and I don't understand how it is supposed to work the way it's written in the article. I've provided the code straight from the article provided below. I've pasted the code here for ease of viewing
First issue - the depedency is instantiated BEFORE (lines 134-137) the tree is created (151-160) - so as soon as you add the depedency to the http.cache (165-167), the OnSiteMapChanged event (242) fires immmediately - making the entire proccess run again - and this loops many times until finally something makes it stop. (i stepped through it and counted the code looping at least 20 times before I gave up on trying to guess when it hit last)
OK, so to fix this I just moved the code to the create the dependency to AFTER the tree is built, right before inserting to http.cache (so HasChanged property is false when adding to http.cache, and you don't get stuck in this psuedo-ifinite-loop).
I still have a problem though - every time a page loads, the BuildSiteMap() hits and line 121 checks if _root is not null - it seems it is never null after it is first built... this is good because I don't want to hit the DB each time. Now, I insert a record into the table... the OnSiteMapChanged event never fires. As I browse pages on the app, the sitemap does not reflect the newly inserted record - stepping through the code, I see that the check at line 121 is still causing the function to short circuit... The sitemap will only refresh if i re-start Visual Studio, which causes the private _root field to become null again, and re-builds the sitemap, reflecting the new changes.. (refreshing the browser or starting new browser instances does not work)...
EDIT: THE ISSUE STEMMED FROM A SILLY 'SET NOCOUNT ON' LINE IN THE TOP OF MY STORED PROC. APPARENTLY THIS BREAKS THE QUERY NOTIFICATION. It seems that this statement is seen as a result set and that the second, actual query statement invalidates the result set resulting in a notification. This was very hard to find and nowhere in the MSDN documentation until I added the comment. Hope this saves someone else the miser I went through!
THE ISSUE STEMMED FROM A SILLY 'SET NOCOUNT ON' LINE IN THE TOP OF MY STORED PROC. APPARENTLY THIS BREAKS THE QUERY NOTIFICATION. It seems that this statement is seen as a result set and that the second, actual query statement invalidates the result set resulting in a notification. This was very hard to find and nowhere in the MSDN documentation until I added the comment. Hope this saves someone else the miser I went through!

"Failed to enable constraints" Error keeps cropping up (seemingly randomly) in my ASP.Net project

I have a weird problem where the "Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints." error sometimes pops up when I am trying to build my project.
The line in question throwing the error was auto-generated code in the designer file for the dataset. To find out the offending table, I used the following code:
Try
Me.Adapter.Fill(dataTable) <--Breakpoint here on the offending line
Catch ex As Exception
For Each TRow As DataRow In dataTable.Rows
If TRow.HasErrors Then
Trace.Write(TRow.RowError)
End If
Next
End Try
Funnily enough, as soon as I run the project after putting in the above code and breakpoint, the error disappears. I assume this has something to do with the code being regenerated. All data is presented successfully, and the project compiles without errors.
However, this has happened often enough for me to frustrate me. Anybody know what might be causing the error and how I can isolate it?
What unique constraint are you placing on the datatable and have you verified that the data your passing in doesn't have any duplicates? If this is coming from a shared database perhaps someone else is modifying the data which could be causing the randomness.
Edit
If that code is exactly as what you have (And forgive me my vb.net is not as strong as my C#). Wouldn't it swallow the exception? In C# we need to rethrow the error.
Add a Trace.Write() right before you go into your for loop.
You are probably working with a typed dataset, or have some code configuration on it. Also you might be reading from one table, and then adding data from another.
In any of those cases, you really want to look into any inconsistencies between the schema. If it is a typed dataset / or configured in code, check its definition, and look for anything different from the sql table. If you are reading from 2 different tables, check the definition of both tables.
Figured it out finally!
The reason the breakpoint wasn't being hit was because the code in question was auto-generated, and had the attribute "DebuggerNonUserCodeAttribute". In addition, in my VS settings, I had set the debugger to "Just my code".
When I ran the code again, and the breakpoint wasn't hit, I noticed the breakpoint icon had changed to a warning. Hovering showed this:
"The breakpoint will currently not be hit. Breakpoints cannot be set in a method or class with the 'DebuggerNonUserCode' attribute when the debugger option 'Just My Code' is enabled."
Ouch!
Once I had removed the "Just My Code" debugging option, the breakpoint was hit, and I discovered that one of the rows had a NULL value in one of the columns which had a non-null constraint. Stupid ole' me!
You should use this code before you fill DataTable :
var dt = new System.DataTable.DataTable();
dt.Clear();
dt.Rows.Clear();
dt.Columns.Clear();

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