I have an access 'application' (.adp file), when it opens i have it update an admin database with the username and time open. When it closes it updates the admin database with username time closed - these are sperate records in the events table so it looks like
username,dbaction,time
bob,open,13:00
gareth,open,13:05
bob,close,14:00
If the user where to open the db twice there would be 2 open and 2 close actions recorded but no way to establish which database session each of the 2 close events belonged.
What i want to store in this table is a unique identifier to link the open and close actions together with 'each session'. Preferably i would like to use a property ov the application object in vba if something exists. Does it even store the time the db was opened? I could generate my own id when databases are opened and store it in a variable until close, but id prefer to use something in built. Any ideas?
I do this using a hidden unbound form which opens on startup. In that form I insert the record into the table. I then fetch the autonumber ID (or whatever SQL Server calls that field.) of that record and store in a text control. If you do any development and you hit an error and reset the running code you lose all global variables thus I prefer using forms to store these kinds of variables.
In the hidden forms On Close event I then update the same record with the date/time exited. I've been using this technique for well over a decade without any problems.
You could have a global 'Id_session' variable, initiated at startup (random generated uniqueIdentifier for example) that you will store in an 'id_Session' column of your 'event' table. When the database is opened, the record is inserted in the 'event' table, and the record identifier is stored as a global variable. When the database is closed, the existing record is identified (through the id_session value) and updated in the database.
In fact, I do not understand the interest of an inbuilt identifier instead of this solution.
There is likely a method that runs in an access database when it is opened. In this you could generate a random identifier and store it in a global variable. When writing your log line you could include this identifier allow you to trace login and logout.
Update: You can use the code shown here to generate a GUID which is pretty much gauranteed to be unique so this should do what you want. If it doesnt you might need to clarify as I'm not understanding the question.
All these answers seem to me to be too clever by half.
What I do is add an Autonumber field to the table I'm logging these in, and then capture the Autonumber value of the startup event record and store it somewhere in (usually in a hidden field on the app's startup form) for use at shutdown to write the shutdown event with the ID number of the startup event.
is HWND going to be unique for 2 access applications opened at the same time on possibly on the same pc or 2 different pcs?
Related
In our web application we want to use DB2 row level access control to control who can view what. Each table would contain a column named userId which contain the user id. We want log-in users be able to see only row's usereId column with theirs id. I have seen db2 permission examples using DB2 session_id or user, for example taking DB2 given Banking example :
CREATE PERMISSION EXAMPLEBANKING.IN_TELLER_ROW_ACCESS
ON EXAMPLEBANKING.CUSTOMER FOR ROWS WHERE BRANCH in (
SELECT HOME_BRANCH FROM EXAMPLEBANKING.INTERNAL_INFO WHERE EMP_ID = SESSION_USER
)
ENFORCED FOR ALL ACCESS
ENABLE;
Our table gets updated dynamically hence we don't know what row get added or deleted hence we don't know what are all the user Id in the table.
At any given time, different user would log-on to the web to view information retrieve from the tables, the permission declaration above only take SESSION_USER as the input, can I change it to something like Java function parameter where one can pass arbitrary id to the permission? If not then how do I handle different log-in users at arbitrary time? Or do I just keep changing SESSION_USER dynamically as new user login (using "db2 set" ??)? If so then is this the best practice for this kind use case?
Thanks in advance.
Since the user ID in question is application-provided, not originating from the database, using SESSION_USER, which equals to the DB2 authorization ID, would not be appropriate. Instead you might use the CLIENT_USERID variable, as described here.
This might become a little tricky if you use connection pooling in your application, as the variable must be set each time after obtaining a connection from the pool and reset before returning it to the pool.
Check out Trusted Contexts, this is exactly why they exist. The linked article is fairly old (you can use trusted contexts with PHP, ruby, etc. now).
I am attempting to create a form that can import data from another database into access, assign an import ID to all the records, copy that data into a master database, and then delete the imported databases so the only remaining databases are the master databases.
I am getting stuck on assigning the import ID. I would like the user to be able to define it in a form and hit a button that executes assigning the value in the form to all the new sets of data. Since this column is not defined in the original set of data I figured the easiest way to do this would be by setting the default value on the master database before copying the data over. However I cannot find a way to change this value without clicking over to the form and changing it manually, which is the exact opposite of what I need to happen.
The reason that I am trying to add the import ID is that I need to nest child tables in the main table and the existing ID starts at 1 for every database and does not remain unique. I figure that I can use the import ID and the existing ID to create a relationship.
Any help is appreciated!
what are you porting to (another access DB or an mysql/mssql?)
but you should be able to set a field in both databases being a integer and using a form to set that field data to whatever the user enters (remember to parse). After the data is set on our outgoing DB you can just push to your master like normal (unless i have not understood the question?) to drop a database in SQL use
DROP DATABASE database_name
You could also use java or .net to delete the database manually after you run you update
BACK END - SQL Server
FRONT END - Access 2010 (2000 format)
The system stores and retrieves data about technical documents. Broadly, there are three tables A, B and C, each of which maintains data about a different type of document.
The ACCESS front end provides a Search Form and Data Entry/Edit form (bound to the underlying table) for each document type. In all three document types, when adding a new record, the user will open the Search form and press a button called "Add". This opens the Data Entry/Edit form and in the Form_Load event is the line
DoCmd.GoToRecord , , acNewRec
When the data entry is complete, the user presses a "Close" button which simply runs the code
DoCmd.Close
As I said, the design and code of the objects relating to the three document types is, for all intents and purposes, identical. However, while for tables A and B the process of adding a new record is seamless and extremely quick, for table C it has proved impossible to add a new record via the ACCESS UI. The edit form will open correctly to add the data, but when the user presses the "Close" button the form hangs, and eventually returns to the Search form without the new record having been added.
It is possible to bypass the UI by opening ACCESS while holding down the SHIFT key, opening the linked table, and adding new records directly. While this is acceptable as an interim measure, it is unacceptable in the long term. It should be noted that the system is about ten years old, and has been working entirely correctly for about nine of those years (apart from minor glitches moving between different versions of ACCESS).
Unfortunately this system is owned and operated by a major global corporation and it is very difficult for me, a subcontracted supplier, to get access to the SQL Server box to run diagnosis (SQL Profiler would be a good starting point). My gut feeling is that there is a subtle difference in the permissions model for that particular table but I don't know.
The situation is further complicated by the fact that I have a copy of the system at my work and I cannot reproduce the problem. Of course, there are bound to be subtle differences between the two architectures (for example, I don't know for certain what version of SQL Server it's running on, but I believe it's 2000, nor do I know how completely it is patched or updated) but the facts are that for one particular table bound to one particular form, it is not possible to add records, whereas for other tables there is no such problem.
I would be grateful if anyone has any ideas about how to go about diagnosing this or even solving it (if anyone has come across the same problem before).
Many thanks
Edward
As a general rule when you encounter problems to update a table, then this tends to suggests that the table does not have a PK or the form the query is based on does not have a PK exposed.
The next thing I would ensure is the table has a time stamp column as Access uses this to test for record changes behind the scenes.
Next up I would check the default locking for the form (while these settings generally don't effect odbc, they should be checked).
Next up is to check if the table has any "bit" column (true/false) and ensure that the defaults for such controls are set SQL SERVER side (they should default to 0). This null bits issue will cause updates to fail if not addressed.
I would also check if the form in question is based on a query or if the data source is set directly to the table. As noted the PK auto number ID of that table in query should be INTEGER value sql side – big int is NOT supported.
So check default values (both in sql table and on the form (those controls) to ensure nothing be set that would prevent the update.
I'm currently creating my first real life project in Pervasive. The task is to map a certain XML structure containing orders (as in shops and products) to 3 tables I created myself. These tables rest inside a MS-SQL-Server instance.
All of the tables have a unique key called "id", an automatically incremented column. I've dropped this column from all mappings so that Pervasive will not try to fill it itself.
For certain calculations, for a split key in one of the tables and for references to the created records in other tables, I will need the id that the database has just created. For that, I have googled the answer. I can use "select ##identity;" as a statement, and this returns the id that has most recently been created for the current connection. This means that in Pervasive, I will have to execute this statement using the already existing target connection object.
But how to do that? I am quite sure that I will need a JDImport or DJExport object, but how to get one associated with the current connection that Pervasive inserts the records by?
Or is there any other way to handle this auto increment when I need to reference the id in other tables?
Not sure how things work in Pervasive, but you may run into issues with ##identity,. Scope_identity() would probably be safer but may still not work in Pervasive.
Hopefully your tables have a natural key in addition to the generated id, in which case you can select your id based on the natural key. This will avoid any issues you may have with disparate sessions and scope.
If there is anyone looking this post up and wonders about the answer, it's "You can't". Pervasive does not allow access to their very own connection object, the one they use to query the database. Without access to it, you cannot guaranteed fetch the right id. The solution for us was this: We used a stored procedure which we called in the Before-Transformation event that created the header record and returned the id and an optional error message as a table. We executed it and it returns the id we then save and use throughout our mapping.
I am getting the following error in an MS Access ADP when trying to add a record on a form linked to a MS SQL Server 2000 table:
Run-time error '31004':
The value of an (AutoNumber) field
cannot be retrived prior to being
saved.
Please save the record that contains
the (AutoNumber) field prior to
performing this action.
note: retrieved is actually spelled wrong in the error.
Does anyone know what this means?
I've done a web search and was only able to find the answer at a certain site that only experts have access to.
First of all, if you are going to look at experts-exchange - do it in FireFox, you'll see the unblocked answers at the bottom of the page.
Second, do you have a subform on that form that's using the autonumber/key field on the master form? Do you require the data that's on that subform to be saved (i.e., having its own key) before the main form is saved. You could be into a deadlock of A and B requiring each other to be saved first.
Other than that, you must somehow be accessing that autonumber field whenyou are saving it. The best I can suggest is to step through the code line by line.
Are you trying to assign the value of an Identity field to a variable or something else before you have saved the record?
For whatever reason, your app is trying to read the value of the identity field before the record has been saved, which is what generates that identity field. In other words, no value exists for the Autonumber field until the row is saved.
I think we'd need to see more code or know more about the steps that lead up to this error to resolve it in more detail.
You should have add some lines of code to show us how you're managing your data and what you are doing exactly. But I am suspecting an issue related to a recordset update. can you identify when the autonumber value is created? Is it available in a control on a form? Can you add a control to display this value to check how it is generated when adding a new record? Is the underlying recordset properly updated? Can you add something like me.recordset.update on some form events: I would try the OnCurrent one ...