got an ADOQuery that has OnNewRecord event.
on the procedure i try to add data automaticaly to another table. the data is a few rows that are needed and handled in clientDataSet in case of cancellation.
at the loc
OtherAdoQuery.insert;
I get error that ADOQuery failed to insert null into a non null field. I am in insert mode, however I NEVER ASKED DELPHI TO POST! i dont find why it posts.
Edit: could you help me find a hint on this problem?
some more clarification:
at
ADOQuery.onNewRecord();
begin
CliendDataSet.insert; //here goes to post for ADOQueryPost. where ClientDataSet was in Browse State
end;
Edit:
this bug does not make sense! look at the stack trace:
beforePost
newRecord
myFunc
where myFunc does cause NewRecord with the Insert.
I'm not too familiar with TAdoQuery, but I know how to track down an error like this. First, if you don't already have it set, go into Project Options and turn on Use Debug DCUs under the Compile tab, then run a full build and run it. When you get that exception report in the debugger, hit Break and you should end up inside the code for the TAdoQuery or one of its sub-objects. Try examining the call stack. If you look up a few calls you'll probably find something that you did is calling something else that's calling Post. Follow the stack trace back until you reach your code and you'll get an idea of what's going on, and if you analyze it a little you should find some way to prevent the problem.
Having said that, let me make a quick guess as to the cause of your problem: When you call Insert on a dataset, if the dataset is already in appending mode because you previously called Insert or Append and didn't follow up with a Post, it will call Post itself before setting up a new row for you to work on. Maybe this is what's happening to you?
the answer was from a connection between the tables.
the ADOQuery.dataSource was set the DataSet of the ClientDataSet.
this mad so much damage, and no hint by the delphi.
Related
Right now I'm struggling to solve a bug that caused by the dataset mode at Delphi (using ADODataset),
details as below for the add button mechanism :
IDMain: =self.DBTextIDUser.Caption+'-'+self.DBEditWorkingDate.Text;
datamodule1.ADODataSetWorkingDetails.Append;
with datamodule1.ADODataSetWorkingDetails do
begin
dbgridworkinghours.Fields[0].AsString := IDMain;
dbgridworkinghours.Fields[7].AsString := self.DBTextIDUser.Caption;
dbgridworkinghours.Fields[8].AsString := self.DBTextName.Caption;
dbgridworkinghours.Fields[9].AsString := self.DBEditWorkingDate.Text;
dbgridworkinghours.Fields[11].AsString := self.DBTextPeriod.caption;
dbgridworkinghours.Fields[10].AsString := self.DBTextToday.Caption;
end;
I already set the adodataset to append mode at the save button :
datamodule1.ADODataSetWorkingDetails.post;
when I click the save button, an error appears that:
The adodataset not in edit/insert mode
I already used this mechanism at the other form and it works
note: I already tried setting the adodataset mode to insert, but still faced the same error
What #kobik said.
Your problem is most likely being caused by something you haven't told us in your q.
I think the important thing is for you to find out how to debug this sort of thing
yourself, so that even if you don't understand the cause, you can at least isolate
it and provide better information when you ask for help here. So I'm going to
outline how to do that.
In your Project Options, check the box "Use Debug DCUs"
Set up two event handlers, for your ADODataSetWorkingDetails's
AfterPost and AfterScroll events, put a some "do nothing" code in both of them
(to stop the IDE removing them). Put a debugger breakpoint on the first line
inside the AfterScroll handler, but not (yet) the AfterScroll one.
Compile and run your program.
You should find that somewhere after you call Append but before you click your
Save button, the debugger stops on your AfterPost breakpoint.
When it does,
go to View | Debug windows | Call stack. This will show you a list of
program lines, the one at the top being the one closest to where the breakpoint
tripped. This will likely be deep inside the VCL's run-time code (which is why
I said to check "Use Debug DCUs". Scroll down the list towards the bottom, and
eventually you should come to a line which is the cause of why Post was called.
If it isn't obvious to you why the AfterPost event was called, put a breakpoint
on your Append line and run the program again. When this breakpoint trips,
put another breakpoint inside your AfterScroll event, resume the program
by pressing F9 and see if the AfterScroll breakpoint is hit. If
it is, again view the Call stack and that should show you why it was called -
if it isn't obvious, then add the contents of tthe Call stack window to your q.
If the cause is obvious, then change your code to avoid it.
The reason I've gone on about the AfterScroll event is that what isn't obvious
is that when your code causes a dataset to scroll, any pending change (because
the dtaset is in dsInsert or dsEdit state will cause the change to be posted
and you will then got the error you've quoted if you try to call Post on the
dataset again. Calling Append initially sets a dataset into dsInsert state, btw.
See if you can at least identify what is causing your dataset to post before
it is supposed to, and let us know in a comment to your q or this answer.
Btw, I strongly recommend that you get out of the habit of using the with construct in your code. Although it may save you a bit of typing, in the long term it will likely make bugs far more likely to happen and far harder to find.
Update TDataSet and its descendants have a State property which is of type TDataSetState (see
DB.Pas). Normally, for browsing data and navigating around the dataset, the
dataset is in dsBrowse state. If you call Edit or Append (or Insert), the dataset
is temporarily put in dsEdit or dsInsert state, respectively. Various routines in DB.Pas
check the dataset state before certain operations are performed and raise an exception if the
DataSet in not in the correct state for the operation to go ahead. It is very, very likely
that it is one of these checks that is giving you the exception.
My original hunch was that your error was occurring because something was happening which
was causing Post to be called, because if Post succeeds, it puts the dataset back into
dsBrowse state, so when clicking your Save button calls Post, the dataset is already
in dsBrowse state. You can, of course, put a breakpoint in TDataSet.Post in DB.Pas
check which state the dataset is actually in when it is called.
There are two other main possibilities for the cause of your exception, namely that
either TDataSet.Cancel or the general Abort method is being called. To investigate
these, put breakpoints on the first lines inside TDataSet.Cancel (in DB.Pas) and
Abort (in SysUtils.Pas). If either of these breakpoints trips between you calling
Append and Post, then you can use the Call Stack view to try and figure
out why execution has reached there.
My Delphi project has a TAdoQuery accesssing data on an MS Sql Server 2014 server, and TClientDataSet that receives the AdoQuery data via a TDataSetProvider. This is created from a Project Template I set up.
Normally, I've found this set-up to work faultlessly, but with this particular project I'm having a problem: ApplyUpdates() fails silently and the Sql Server data is not updated. In my stripped down debugging project, the only code I have, apart from a button-click handler which calls it, is:
procedure TForm1.ApplyUpdates;
var
Errors : Integer;
begin
Errors := ClientDataSet1.ApplyUpdates(0);
Caption := IntToStr(Errors) + '/' + IntToStr(ClientDataSet1.ChangeCount);
end;
After this executes, the form's caption should be 0/0 of course but what it actually says is 0/1. So on the face of it, no errors occurred but the CDSs ChangeCount hasn't been reset to zero as it should be. My q is, how can ApplyUpdates return no errors but the server dataset doesn't get updated.
Fwiw, I added the ChangeCount display as part of my effort to debug the problem. But I'm afraid I haven't been able to follow what's supposed to be going on in the details of the "conversation" between the DataSetProvider and its DataSet to apply the updates on the server.
I ran into this problem recently on a quick project I rustled up without the precaution of setting an OnReconcileError handler, as queried by #mjn.
Once I'd set up the OnReconcileError handler, it was obvious that the problem was that the provider's TSqlResolver wasn't able to identify the row to update. Iirc, the message on the ReconcileError pop-up form was words to the effect of "Unable to locate record. No key specified."
So, first thing I tried was to include this in my CDS's AfterOpen:
CDS1.Fields[0].ProviderFlags := [pfInKey];
(CDS1.Fields[0] is the PK field of the dataset)
Contrary to my expectations, that didn't fix it. After scratching my head for a while, I had a careful look on the server and discovered that the recently-recreated table I was using did not have a primary key index.
Once I'd created the primary key index on the server, the ApplyUpdates problem went away.
However, what puzzles me about this is that prompted by your q, I dropped the primary key index on my server table and the problem hasn't started occurring again (!). I'm guessing this is due to some kind of cacheing effect on my machine but I don't really want to reboot it right now to investigate.
I have the following query to one of my database tables:
select count(*) as mycount
from mytable
where fieldone = :fieldone
and fieldtwo = :fieldtwo
Parameters are correctly loaded into the query (both of type String).
When I run this query outside the app (for instance, through the dbexplore) and replace the parameters with the actual values, I get the correct result. But when running it in the app, I get a Field 'fieldtwo' not found error, right on the Query.Open call.
Why would the BDE not find this field, when it actually exist?
Update: The following query, executed right after the first one (the one that fails), works fine in the app:
select *
from mytable
where fieldone = :fieldone
order by fieldone, fieldtwo
The best guess is that you have populated the field list in the query, this overrides any concept of the underlying fields that are in the query and is a cause of countless confusion.
Right click on the query, pick the fields editor clear all the values that are there and then choose 'add all fields' that should cause the missing field to appear once the query is executed.
I think it should auto-populate the fields if there are no defined fields when the query is executed, so you may not need to choose 'add all fields' after clearing the fields.
Whenever we come across a problem like this we tend to remove the query from the form and create it dynamically at run time... It depends how ingrained into the form it is...
E.g. If you have a data aware control looking at "fieldtwo" which tries to fetch some data when the underlying data set gets updated then it'll trigger an error like this, but it's more obvious when you've written code such
SomeEdit.Text = Query.FieldByName("fieldtwo").AsString;
That way it falls over on the relevant line instead of the open (triggering a related event)
Clear the query content using Query1.SQL.Clear; statement before opening it.
Other reason can be you are opening other database which may not have the specified field. Be sure that both the DatabaseName's in your app and dbexplore are same
I used to face porblems with BDE when i have SQLExplorer open and the app accesses the DB at the same time (but i had errors like ), try closing the Explorer it may help, if not i would build the SQL as text without the Parameters and try if it works then (if its possible in your situation).
I don't use parameters, so I'm just grabbing at straws here. I still use the BDE regularly, but am no expert. I find I shy away from more complex expressions (which yours is not!) because of the little "surprises" like this that the BDE throws at you.
Perhaps adding parentheses:
where (fieldone = :fieldone)
and (fieldtwo = :fieldtwo)
Or, single or double quote signs (this probably will make it worse?)
where (fieldon = ":fieldone")
and (fieldtwo = ":fieldtwo")
Or, to explore the problem, remove the "and fieldtwo = :fieldtwo" line and see if it runs.
Would it be possible for you to do your own parameter substitution with a StringReplace as in
Query1.SQL.Text := StringReplace(Query1.SQL.Text, ":fieldone", "MyVarName",[rfReplaceAll ]);
If you are creating a ClienDataSet in memory by the Create DataSet method, you should check the TFieldDefs property, which must have a different field name or not created
I was having a weird but small problem, I'll post in case it will help someone in some day.
uRegPeople.pas
with frmEditPerson do
begin
PersonID := qryPerson.FieldByName(ID).AsInteger;
...
end;
I had qryPerson both in frmRegPeople and in frmEditPerson, by using with I was referencing to frmEditPerson.qryPerson, however I wanted to reference to frmRegPeople.qryPerson. Then I need to change to the following code.
with frmEditPerson do
begin
PersonID := Self.qryPerson.FieldByName(ID).AsInteger;
...
end;
// Explanation
// qryPerson --> frmEditPerson.qryPerson;
// Self.qryPerson --> frmRegPeople.qryPerson;
Seems my appreciation for the Entity Framework is taking a serious hit. The "MS almost got it right, but they just missed it because of something L-A-M-E" thought is coming up. Until today everything has been fine. For some unknown reason, it won't compile anymore with Error 2048. I've read up on this and I've seen how you need to map all three operations. Why is this even necessary? What I if I don't need a delete function and only need insert and update? I tried mapping a dummy SP to my delete function. If that fixes my problem, however cheezy, fine. Only problem is, it just created more problems.
Here's what I have. I'm writing a simple newsletter app in MVC. I have entities for a publication, issue and article all generated from my DB (SQL 08). I set up the the relationships in my DB and they translated fine to my EDMX. I made some SPs to insert and update my issues and article. I added them to the EDMX and mapped them accordingly. I don't need a delete function for any of them and I don't need anything for the publication entity. Why is the compiler forcing me to map all functions? IMO, this a MAJOR, MAJOR PROBLEM with EF4 and I can't believe MS would release it with this kind of crap coming up.
The other strange issue is I've tried mapping sp's to entities in another project and configured with only insert and update and they compile fine. Why is the compiler inconsistent?
I would rather not resort to having to use the Imported Functions. Is that my only option? If that's the case it eliminates the ability to the SaveChanges method. Come On MS!!! Fix this!!!!!!!
After much digging and side by side text comparison, I think I have found the solution.
The SP in question was set up like
CREATE PROCEDURE updateArticle
(
#ArticleID INT,
#Content TEXT
)
where it should have been something like
CREATE PROCEDURE updateArticle
(
#ArticleID INT,
#IssueID INT,
#Content TEXT
)
Now, I still don't know why EF4 even requires this since I'm not updating the issueid and the error message lends little help in diagnosing the problem. My SP doesn't even use the IssueID, but EF needs it regardless. Hopefully this will help someone down the road. MS still could do a better job regarding the need for this.
I use nested database stuctures with TClientDataSets. I'm new to programming so my lingo is ten-to-one wrong.
My problem is as follows: I defined my database stucture and all the fields of the nested stuctures and then I called the CreatDataSet method of the master clientDataSet and it worked. I then wanted to add another data field to the master ClientDataSet. I then called the ClearData method of the Master ClientDataSet and then tried to create the new stucture by calling CreateDataSet again. It is here where I encounter my problem. I get the 'Invalid field type error' and I don't really know or understand what what the problem is.
So how do I create an exsta field after I called the createdata set method, then called the cleardata method, then added a field and then calling the createdataset method again without getting the 'invalid field type error?
Does anybody have any information about this problem. I use Delphi 2007
Kind Rgards
Riaan de Villiers
It is a Delphi bug.
Call YourDataset.FieldDefs.Clear before calling CreateDataSet and it should work.
For more infomation please look at this QC Report:
http://qc.codegear.com/wc/qcmain.aspx?d=38984
EDIT:
After reading your problem more carefully, the problem might be something else, but please try the FieldDefs.Clear and let me know the results.
It has been a long time since you asked this question, but I believe the problem has specifically to do with the nested dataset fields. I've seen this error before, and I believe that it has to do with the order in which the particular fields are created. If I remember correctly, if you try to create the master dataset before the nested dataset fields are defined or created, you get this invalid field type error.
Begin by removing your nested dataset fields from the equation and see if you still get the problem. If not, then add them back. Try creating the master dataset and its nested datasets in different orders.
I know this is late, but I hope it helps.