For PowerApps, what data source, other than SharePoint lists are accessible via Powershell?
There are actually two issues that I am dealing with. The first is dynamic updating and the second is the 500 item limit that SharePoint lists are subject to.
I need to dynamically update my data source, which I am currently doing with PowerShell. My data source is not static and updating records by hand is time-consuming and error prone. The driving force behind my question is that the SharePoint list view threshold is 5,000 records however you are limited to 500 visible and searchable records when using SharePoint lists in the Gallery View and my data source contains greater than 500 but less than 1000 records. If you have any items beyond the 500th record that should match the filter criteria, they will not be found. So SharePoint lists are not optional for me until that limitation is remediated
Reference: https://powerapps.microsoft.com/en-us/tutorials/function-filter-lookup/
To your first question, Powershell can be used for almost anything on the Microsoft stack. You could use SQL server, Dynamics 365, SP, Azure, and in the future there will be an SDK for the Common Data Service. There are a lot of connectors, and Powershell can work with a good majority of them.
Take note that working with these data structures through Powershell is independent from Powerapps. Powerapps just takes the data that the data connector gives it, and if you have something updating the data in the background (Powershell, cron job, etc.), In order to get a dynamic list of items, you can use a Timer control and a Refresh function on your data source to update the list every ~5-20 seconds.
To your second question about SharePoint, there is an article that came out around the time you asked this regarding working with large lists. I wouldn't say it completely solves your question, but this article seems to state using the "Filter" function on basic column types would possibly work for you:
...if you’d like to filter the set of items that you are showing in the gallery control, you will make use of a “Filter” expression, rather than the “Search” expression, which is the default that existing apps used. With our changes, SharePoint connector now supports “equals” type of queries on columns that support filtering (Single line of text, choice, numbers, dates and people), so make sure that the columns and the expressions you use are supported and watch for the same warning to avoid reverting back to the top 500 items.
It also notes that if you want to pull from a list larger than the 5k threshold, you would need to use indexes, I have not fully tested this yet but it seems that this could potentially solve your problem.
Related
I am creating a data dictionary and I am supposed to track the location of any used field in a workbook. For example (superstore sample data), I need to specify which sheets/dashboards have the [sub-category] field.
My dataset has hundreds of measures/dimensions/calc fields, so it's incredibly time exhaustive to click into every single sheet/dashboard just to see if a field exists in there, so is there a quicker way to do this?
One robust, but not free, approach is to use Tableau's Data Catalog which is part of the Tableau Server Data Management Add-On
Another option is to build your own cross reference - You could start with Chris Gerrard's ruby libraries described in the article http://tableaufriction.blogspot.com/2018/09/documenting-dashboards-and-their.html
I'm planning on using rxdb + hasura/postgresql in the backend. I'm reading this rxdb page for example, which off the bat requires sync-able entities to have a deleted flag.
Q1 (main question)
Is there ANY point at which I can finally hard-delete these entities? What conditions would have to be met - eg could I simply use "older than X months" and then force my app to only ever displays data for less than X months?
Is such a hard-delete, if possible, best carried out directly in the central db, since it will be the source of truth? Would there be any repercussions client-side that I'm not foreseeing/understanding?
I foresee the number of deleted's growing rapidly in my app and i don't want to have to store all this extra data forever.
Q2 (bonus / just curious)
What is the (algorithmic) basis for needing a 'deleted' flag? Is it that it's just faster to check a flag rather than to check for the omission of an object from, say, a very large list. I apologize if it's kind of a stupid question :(
Ultimately it comes down to a decision that's informed by your particular business/product with regards to how long you want to keep deleted entities in your system. For some applications it's important to always keep a history of deleted things or even individual revisions to records stored as a kind of ledger or history. You'll have to make a judgement call as to how long you want to keep your deleted entities.
I'd recommend that you also add a deleted_at column if you haven't already and then you could easily leverage something like Hasura's new Scheduled Triggers functionality to run a recurring job that fully deletes records older than whatever your threshold is.
You could also leverage Hasura's permissions system to ensure that rows that have been deleted aren't returned to the client. There is documentation and examples for ways to work with soft deletes and Hasura
For your second question it is definitely much faster to check for the deleted flag on records than to have to try and diff the entire dataset looking for things that are now missing.
This should be pretty straight forward, just haven't been able to find any documentation, so unsure if it is possible, and if it is - how.
I'm calling the Sharepoint 2013 REST API, specifically the Excel REST services (ExcelRest.aspx), to fetch values from specific cells in an Excel workbook.
I've had success with the following two types of calls:
Fetch one specific cell (E5):
http://somesharepointsite.com/testsite/_vti_bin/ExcelRest.aspx/Shared%20Documents/Excelfile.xlsx/Model/Ranges('''Front%20page''!E5')?$format=html
Fetch range (E5-F20):
http://somesharepointsite.com/testsite/_vti_bin/ExcelRest.aspx/Shared%20Documents/Excelfile.xlsx/Model/Ranges('''Front%20page''!E5|F20')?$format=html
However I would very much like to be able to fetch multiple specific cells e.g: E5, E7, F15, F18.
This is due to how the information is placed in the spreadsheet, which isn't really convenient for automated extration. So instead of counting rows/columns to find relevant cells when extracting a range, it would much easier if all cells of relevance could be indicated directly.
I know I could just make a bunch of separate calls fetching one cell at the time, but that doesn't really seem like the optimum solution.
I've tried separating the range with commas, semicolons - also tried making two separate Ranges - no luck
Any suggestions are welcome
Actually, simplify the problem. I would create a hidden sheet that puts all the relevant data in a single range that you can pull from and give it a Named Range. Then call that Range. These values are linked the the master sheet. Hidden only in there's no reason to confuse anyone if they open up the spreadsheet.
So I've started learning access due to necessity, as the person who was in charge of it passed way and someone had to keep it going.
I noticed a very bad (at least IMO) behavior in all databases he created: Every single form was bound directly to a table or saved query. This way, if the user opened a form, he had to complete all the steps he was supposed to do, because if he closed the form mid process (or the computer froze, or anything of the sort), the actual data would be compromised as it would be half complete. This often times broke everything in the process chain, rendering sub-sequential steps impossible to be performed and forced me to correct data manually directly in the tables.
As I've start upgrading his stuff and developing my own, I've been trying to learn ways to allow the data to be edited in the form only, making it possible to cancel the process anytime or save the changes all at once in the end.
If the editions were simple, I discovered that I could create a recordset, copy relevant data to unbound fields in the form and, in the end, if the user chose to, copy the data from the form fields back to the recordset.
Other times more complex solutions were required, as I would need to edit several pieces of data at once in continuous forms, "save" them, run more code, maybe add fields to hold the information originated from that processing and so on. I then learned about using temporary tables, but did not like it, since it tended to bloat the db. I even went on to creating temporary databases during code execution that would host the temporary tables and be destroyed in the end, but that added too much unnecessary complexity.
Nowadays I'm using disconnected ADO recordsets to hold the temporary data and fields. It works but has its limitations.
So I'm wondering, what is the best way you - much more experienced than me - guys use to approach this kind of scenario? Is using in memory ADO recordsets really the best way around?
I think you are mixing two things that a form does that have completely different requirements. Editing existing records (and bound forms are great for that) and creating new records (where using a straight bound form can result in creating incomplete records). The way to approach it depends on many things but mainly to how much data is necessary for a new record to be considered "complete".
I usually do one of the following things:
Create an unbound popup modal form for adding new records where only the necessary fields are present. Once complete it loads the new record to the main form for further editing.
Use the above method except the form is not a popup one but a set of unbound fields in the footer or header of the main form.
Let the user create new records but bind validation on the OnClose (and/or other appropriate to your situation) event of the form that deletes the half-filled record if it does not validate.
Let users create new records in the bound form but have a 'cleanup' routine called either on a schedule or based on user actions.
Ultimately if your business process requires the majority of fields to be manually added/edited every time a new record is added or edited, you are better off using an unbound form.
This way, if the user opened a form, he had to complete all the steps
he was supposed to do, because if he closed the form mid process (or
the computer froze, or anything of the sort), the actual data would be
compromised as it would be half complete
No, if the computer freezes, then no data is saved to the table. This is the same if you used a disconnected reocrdset and a un-bound form.
If you use the before update event in the form that has some verification code and does a simple cancel = true, then the forms data is not saved nor is the table updated. Again, if you used a dis-connected record set and the user closes the form, you have to test the data – and again you can either choose to write out the data or not – this effect is ZERO difference from using a bound form to a table or a disconnected form.
If the editions were simple, I discovered that I could create a
recordset, copy relevant data to unbound fields in the form and, in
the end, if the user chose to, copy the data from the form fields back
to the recordset.
No you don’t need to do the above. The above achieves nothing and only racks up additional development hours and increases cost of the application. In near all cases in-bound forms increase development costs over that of a simple form bound to a table. So the original developer had the correct idea. You can control the update of the underlying table in near all cases to achieve the required verification. Forms only save and write the data out if the developer allows as such.
So Access forms when bound no more or less write incomplete data out to a table if you place verification code in the forms before update event. A half-filled bound form, or a half filled un-bound form with dis-connected reocrdset BOTH will not write their data if the computer freezes.
And BOTH types of forms will not write out data to table until such time your verification code has completed.
Access is not designed for un-bound forms, and tools like vb.net, or even VB6 had a whole bunch of cool wizards and support for un-bound forms. In access, we don't have those wizards. And when you use UN-bound forms then you loose tons of form events. You in effect get the worst of both worlds, since you lose use of form events and have no wizards or support for un-bound. Even just the several delete record events we have are rather amazing.
You lose use of me.dirty, on-insert, me.newReocrd, forms after update events - the list of features you toss out and lose is huge. And if you want a button to write data to the table (such as a save button on the form), then just go:
If me.Dirty = True then
me.Dirty = False ' this forces your verification code to run
End if
There are FEW use cases in which in-bound forms will benefit you, but they will cost you rather much in terms of development times.
I keep seeing questions floating through that make reference to a column in a database table named something like DateLastUpdated. I don't get it.
The only companion field I've ever seen is LastUpdateUserId or such. There's never an indicator about why the update took place; or even what the update was.
On top of that, this field is sometimes written from within a trigger, where even less context is available.
It certainly doesn't even come close to being an audit trail; so that can't be the justification. And if there is and audit trail somewhere in a log or whatever, this field would be redundant.
What am I missing? Why is this pattern so popular?
Such a field can be used to detect whether there are conflicting edits made by different processes. When you retrieve a record from the database, you get the previous DateLastUpdated field. After making changes to other fields, you submit the record back to the database layer. The database layer checks that the DateLastUpdated you submit matches the one still in the database. If it matches, then the update is performed (and DateLastUpdated is updated to the current time). However, if it does not match, then some other process has changed the record in the meantime and the current update can be aborted.
It depends on the exact circumstance, but a timestamp like that can be very useful for autogenerated data - you can figure out if something needs to be recalculated if a depedency has changed later on (this is how build systems calculate which files need to be recompiled).
Also, many websites will have data marking "Last changed" on a page, particularly news sites that may edit content. The exact reason isn't necessary (and there likely exist backups in case an audit trail is really necessary), but this data needs to be visible to the end user.
These sorts of things are typically used for business applications where user action is required to initiate the update. Typically, there will be some kind of business app (eg a CRM desktop application) and for most updates there tends to be only one way of making the update.
If you're looking at address data, that was done through the "Maintain Address" screen, etc.
Such database auditing is there to augment business-level auditing, not to replace it. Call centres will sometimes (or always in the case of financial services providers in Australia, as one example) record phone calls. That's part of the audit trail too but doesn't tend to be part of the IT solution as far as the desktop application (and related infrastructure) goes, although that is by no means a hard and fast rule.
Call centre staff will also typically have some sort of "Notes" or "Log" functionality where they can type freeform text as to why the customer called and what action was taken so the next operator can pick up where they left off when the customer rings back.
Triggers will often be used to record exactly what was changed (eg writing the old record to an audit table). The purpose of all this is that with all the information (the notes, recorded call, database audit trail and logs) the previous state of the data can be reconstructed as can the resulting action. This may be to find/resolve bugs in the system or simply as a conflict resolution process with the customer.
It is certainly popular - rails for example has a shorthand for it, as well as a creation timestamp (:timestamps).
At the application level it's very useful, as the same pattern is very common in views - look at the questions here for example (answered 56 secs ago, etc).
It can also be used retrospectively in reporting to generate stats (e.g. what is the growth curve of the number of records in the DB).
there are a couple of scenarios
Let's say you have an address table for your customers
you have your CRM app, the customer calls that his address has changed a month ago, with the LastUpdate column you can see that this row for this customer hasn't been touched in 4 months
usually you use triggers to populate a history table so that you can see all the other history, if you see that the creationdate and updated date are the same there is no point hitting the history table since you won't find anything
you calculate indexes (stock market), you can easily see that it was recalculated just by looking at this column
there are 2 DB servers, by comparing the date column you can find out if all the changes have been replicated or not etc etc ect
This is also very useful if you have to send feeds out to clients that are delta feeds, that is only the records that have been changed or inserted since the data of the last feed are sent.