I have been using Lazarus 2.x (free pascal) with firebird 3 (via flamerobin) and i try to commit records via TSQLConnection, TSQLQuery, TDBConnection in data module (appeals) etc.
I run the following code snippet and the records are successfully commited to firebird, but unfortunately DB connection afterwards is lost and thus there is not any record to be seen via DBGrid (not even column headers - totally blank). I have to terminate the application and reopen it to gain visual insight of my firebird via DBGrid.
Button click event
appeals.SQLTransaction1.Active:=false;
appeals.SQLQuery1.SQL.Text:='UPDATE appeals set name=:name,date_entry=:entry,date_suspended=:suspended,'+
'date_court=:court,date_judgement=:judgement where id='+IntToStr(row_num);
appeals.SQLQuery1.Params.ParamByName('name').AsString:=Trim(Edit1.Text);
appeals.SQLQuery1.Params.ParamByName('entry').AsDate:=DateTimePicker1.Date;
appeals.SQLQuery1.Params.ParamByName('suspended').AsDate:=IncDay(DateTimePicker1.Date,10);
appeals.SQLQuery1.Params.ParamByName('court').AsDate:=DateTimePicker2.Date;
appeals.SQLQuery1.Params.ParamByName('judgement').AsDate:=IncDay(DateTimePicker2.Date,20);
appeals.SQLTransaction1.StartTransaction;
appeals.SQLQuery1.ExecSQL;
appeals.SQLTransaction1.Commit;
I have also used .CommitRetaining as exactly mentioned in lazarus forum without success. Any idea what could i do in order to see my records live in DBGrid after commit.
Regards
The reason the DBgrid shows nothing is that SqlQuery1.ExecSQL does not return a result set, so SqlQuery1 cannot supply any records for the DBGrid to display. So call SqlQuery1.Open after your Commit.
However, before you can call SqlQuery1.Open, you need to give it a SELECT statement to Execute, because a SQL UPDATE statement does not return a result set, as you have already found. So, do something like:
[...]
appeals.SQLTransaction1.StartTransaction;
appeals.SQLQuery1.ExecSQL;
appeals.SQLTransaction1.Commit;
appeals.SQLQuery1.Sql.Text := 'Select * from appeals where ...';
appeals.SQLQuery1.Open;
obviously replacing '...' in the 'where' clause by something appropriate. Normally. a SELECT query should be parameterised to limit the number of rows returned and the amount of time the table is locked on the server.
Related
I have a long-running page in Oracle Apex, this is an interactive report page, which fetches the report based on the Username, From_Date and To_Date parameters users provide.
The query used for this report page is executing without any issues(0.07 Sec) in SQL developer. When I checked the Debug log to debug the long run, I found the statement "... do not save: same value / password / no session" in the log which is the reason for the long run. The page never loads and end up in a gateway time out. The expected number of rows for the given parameters in mere 161 rows. Please find the screenshot of the debug log below. Please help me with this.
At the beginning I found a different issue in the Debug Log, which was due to 'IR binding: "APXWS_MAX_ROW_CNT" value="1000000"'. Later I removed the Maxrowcount value and made it null. So this was taken care.
A few ideas; see whether any of those helps.
How do you run the report? Did you set "Page action on selection" for those parameters to "Submit"?
If not, how about creating a SUBMIT button which would submit the page (and, thus, put items' values into session state)?
If you use a source for those items, try to set them to be used "always, replacing any existing value in session state".
I have a requirement where 300 columns had to be processed. I am trying to achieve this using IG automatic row processing (DML). When writing the code in the editor I get a error stating 'Value too long by 2015 characters'.
I suppose this is an Oracle Apex limitation. Can someone please share their views on this?
When writing the code in the editor ...
I'd say that your problem isn't related to number of columns, but a large query which can't fit into "SQL Query" item of the Page Designer.
Which Apex version do you use? I can't tell for sure (as I don't know it), but my impression is that Apex up to version 4.2 had that item limited to VARCHAR2(4000) so - if your query is larger than that, it won't fit (such as in your case - query you wrote is 2015 characters longer than the maximum size the item allows). In 5.x version, you can put a whole lot of query into the item (as if it was modified to a CLOB).
Now, as you use Interactive Grid and it appeared in 5.x version, huh ... maybe what I wrote above isn't entirely true. Unfortunately, you can't switch to a query whose source is a function that returns query (such as in Classic Reports), as you could write a (stored) function and simply call it from Apex.
As you said that you used automatic row processing, did you put too much code somewhere in there?
On the other hand, I Googled a little bit, looking for limit of column numbers in the IG - couldn't find anything official, but someone complained (here, on StackOveflow) that they tried to create an IG with over 100 columns, and it didn't work.
So, yes - maybe you hit the limit, but I can't confirm it. Hopefully, someone who knows Apex better will be able to assist. Alternatively, consider asking the same question on OTN forums, as people who designed Apex answer questions there.
I have an interactive report, where the query is combined, so I can't use editable interactive grid. That's why I have to use manual form in my query.
I've found some nice tips about the APEX_ITEMs, but I have problem with my process.
In my query there are columns like:
APEX_ITEM.HIDDEN(1,coursestudent.id)
...
APEX_ITEM.SELECT_LIST(2,coursestudent.signed,'Signed;1,Failed;0')
I have a submit button, and here is my process:
FOR i in 1..apex_application.g_f01.count LOOP
UPDATE coursestudent
SET signed=apex_application.g_f02(i)
WHERE id=apex_application.g_f01(i);
END LOOP;
I've thought that it's not too difficult, but after I press Submit nothing happens, except that the Success message is written out the page.
What should I do?
I'm using the Oracle Apex version: 5.1.1.00.08
Thanks to Jeffrey, I found the error: it is a bug.
I had to copy-paste the sql query again, and it works now. Ok, really, in that case I always put a select 1 from dual in it's place, save, and just after that paste back the query.
I've faced this bug before that, sometimes the new columns just don't showing in the page. Since I put the hidden column after I first create the query, it hadn't shown in the page, so the loop in the process never worked.
When I issue a query like select * from city; using oracle sql developer in mac I get the output that is not aligned and it is very hard to read. How do I get the grid view and set it as default?
Sounds like you're getting the script output. You can have that formatted nicely by using SET SQLFORMAT ansiconsole, we'll make the columns line up as nice as possible based on the size of the display.
But if you want the data back in a grid, use Ctrl+Enter or F9 or the first execute button in the toolbar to execute.
This will get you the output in a grid, like this:
I talk about both executing as a script or statement here.
If your issue is with formatting, you may want to look at this link
If your issue is with records not getting inserted, please note these.
Records inserted in one session will not be visible in another session unless they are committed.
If you are checking the count in the same session where you inserted the records, then check for errors in insert. Add a show errors command at the end of your script, "path_to_file.sql" to check if any errors occurred while inserting the records.
Hope this helps.
We need to return subset of records and for that we use the following command:
using (SqlCommand command = new SqlCommand(
"SELECT ID, Name, Flag, IsDefault FROM (SELECT ROW_NUMBER() OVER (ORDER BY #OrderBy DESC) as Row, ID, Name, Flag, IsDefault FROM dbo.Languages) results WHERE Row BETWEEN ((#Page - 1) * #ItemsPerPage + 1) AND (#Page * #ItemsPerPage)",
connection))
I set a SqlCacheDependency declared like this:
SqlCacheDependency cacheDependency = new SqlCacheDependency(command);
But immediately after I run the command.ExecuteReader() instruction, the hasChanged base property of the SqlCacheDependency object becomes true although I did not change the result of the query in any way! And, because of this, the result of this query is not kept in cache.
HttpRuntime.Cache.Insert( cacheKey, list, cacheDependency, Cache.NoAbsoluteExpiration, TimeSpan.FromMinutes(AppConfiguration.CacheExpiration.VeryLowActivity));
Is it because the command has 2 SELECT statements? Is it ROW_NUMBER()? If yes, is there any other way to paginate results?
Please help! After too many hours, a little will be greatly appreciated! Thank you
Running into the same issue and finding the same answers online without any help, I was reasearching the xml invalid subsicription response from profiler.
I found an example on msdn support site that had a slightly different order of code. When I tried it I realized the problem - Don't open your connection object until after you've created the command object and the cache dependency object. Here is the order you must follow and all will be good:
Be sure to enable notifications (SqlCahceDependencyAdmin) and run SqlDependency.Start first
Create the connection object
Create the command object and assign command text, type, and connection object (any combination of constructors, setting properties, or using CreateCommand).
Create the sql cache dependency object
Open the connection object
Execute the query
Add item to cache using dependency.
If you follow this order, and follow all other requirements on your select statement, don't have any permissions issues, this will work!
I believe the issue has to do with how the .NET framework manages the connection, specifically what settings are set. I tried overriding this in my sql command test but it never worked. This is only a guess - what I do know is changing the order immediately solved the issue.
I was able to piece it together from the following to msdn posts.
This post was one of the more common causes of the invalid subscription, and shows how the .Net client sets the properties that are in contrast to what notification requires.
https://social.msdn.microsoft.com/Forums/en-US/cf3853f3-0ea1-41b9-987e-9922e5766066/changing-default-set-options-forced-by-net?forum=adodotnetdataproviders
Then this post was from a user who, like me, had reduced his code to the simplest format. My original code pattern was similar to his.
https://social.technet.microsoft.com/Forums/windows/en-US/5a29d49b-8c2c-4fe8-b8de-d632a3f60f68/subscriptions-always-invalid-usual-suspects-checked-no-joy?forum=sqlservicebroker
Then I found this post, also a very simple reduction of the problem, only his was a simple issue - needing 2 part name for tables. In his case the suggestion resolved the issue. After looking at his code I noticed the main difference was waiting to open the connection object until AFTER the command object AND the dependency object were created. My only assumption is under the hood (I have not yet started reflector to check so only an assumption) the Connection object is opened differently, or order of events and command happen differently, because of this association.
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/bc9ca094-a989-4403-82c6-7f608ed462ce/sql-server-not-creating-subscription-for-simple-select-query-when-using-sqlcachedependency?forum=sqlservicebroker
I hope this helps someone else in a similar issue.
Just a guess, but could it be because your SELECT statement doesn't have an ORDER BY clause?
If you don't specify an explicit ordering then it's possible for the query to return the results in any order each time it is run. Maybe this is causing the SqlCacheDependency object to think that the results have changed.
Try adding an ORDER BY clause:
SELECT ID, Name, Flag, IsDefault
FROM
(
SELECT ROW_NUMBER() OVER (ORDER BY #OrderBy DESC) AS Row,
ID, Name, Flag, IsDefault
FROM dbo.Languages
) AS results
WHERE Row BETWEEN ((#Page - 1) * #ItemsPerPage + 1) AND (#Page * #ItemsPerPage)
ORDER BY Row
i'm no expert on SqlCacheDependency, in fact, i found this question whilst looking for answers to my own issues with it! However, i believe the reason your SqlCacheDependency is not working is because your SQL contains a nested sub query.
Take a look at the documentation which lists what you can/can not use in your SQL: Creating a Query for Notification
"....The statement must not contain subqueries, outer joins, or self-joins....."
I also found some invaluable troubleshooting info from a guy at Redgate here: Using and Monitoring SQL 2005 Query Notification that helped me solve my own problem: By using Sql Profiler to trace the QN events he suggests, i was able to spot my connection was incorrectly using the 'SET ARITHABORT OFF' option, causing my notifications to fail.