Are you thinking of attending Data Modelling Zone in Düsseldorf in September 2018?
– then –
This session is for you!
Join the author of Data Modelling Made Simple with PowerDesigner, and learn the Fundamental techniques you need to get the best out of SAP PowerDesigner.
The program hasn’t been announced yet, so watch the conference web site for announcements.
Late last year, SAP issued Service Pack 5 for PowerDesigner 16.6. From the list of new features, it’s obvious that SAP are putting a lot of focus on the web-editing capabilities of the tool. In this service pack, there are changes that affect process modellers, enterprise architects, requirements modellers, and data architects. I shan’t list them all here – see the note below for details of how to access them yourself.
I’m going to focus on what matters to data architects – the new support for Amazon Redshift. SAP have done the usual excellent job of enhancing the underlying database support in the Physical Data Model (PDM) in order to handle this DBMS. For example, they’ve added a new type of object, “External Schema”, and extended the properties available for Tables, Columns, Views, and Users. The latter includes recognising Schemas as a Stereotype of User.
For example, here’s the new ‘general’ tab for a column – I’ve highlighted some of the new properties for you.
To find out more about these new features, follow these two simple steps:
· Search for PowerDesigner stuff on SAP.com – https://help.sap.com/viewer/p/SAP_POWERDESIGNER
· click on the “New Features Summary” link
In yesterday’s blog post, I described how to convert CamelCase object Codes into ‘Proper Case’ object Names, using a combination of GTL and VBScript in a model extension. This took advantage of the built-in conversion routines, which enable us to convert abbreviations into plain language, such as replacing “acct” with “account”.
I didn’t show you how to tell PowerDesigner where to look for those abbreviations, so that’s what I’m going to do now. The secret lies with the Naming Conventions in the Model Options. There are three ways to access the Model Options:
Click on the “Naming Conventions” section, then on the “Code to name” sub-tab, as shown below. You need to do two things:
The drop-down list of conversion tables will include entries from the following sources:
You can edit your conversion table directly, without using Excel – just click on the ‘Edit Selected Conversion Table’ button.
Each time you run the menu options I showed you yesterday, it will use the current conversion table. If, for example, you haven’t defined ‘BBC’ as an abbreviation, the code ‘BBCNews’ will be converted to ‘BBC News’. If you decide that ‘BBC’ should be converted to “British Broadcasting Corporation”, just add the following entry to your conversion table, and run the menu options again.
|British Broadcasting Corporation||BBC|
Lastly, it’s worth pointing out that the Conversion table that you select on the Naming Conventions tab is used for every type of object, unless you select a different Conversion table in one of the object-specific sections. In this example, I’ve chosen a different Conversion table for Columns:
So, you could use different conversion tables for different types of object, if you want to.
Every object in PowerDesigner actually has two labels, which we refer to as the Name and the Code. The Name is the ‘business’ or ‘human’ name for an object, and the Code is a technical name for the object. The Naming Conventions allow you to automatically convert the ‘business’ names into the ‘technical’ codes, like this set of LDM attributes:
As well as changing the case, and replacing spaces with underscores, we can replace words and phrases with their abbreviations, using a CSV file or the PowerDesigner glossary as the source. Here are the same attributes, after changing the standard for codes to UpperCamelCase, and applying abbreviations from a CSV file.
That’s fine if you’re forward-engineering, creating technical artefacts from your models, but what if you’re reverse-engineering, and those technical names (the PowerDesigner codes) are your starting point?
When you reverse-engineer a database in PowerDesigner, the only names available are the technical names, so the PowerDesigner Names and Codes are the same. Synchronisation is automatically turned off, so you can manually edit names without accidentally changing the codes (the technical names). For example, here’s part of the model created by reverse-engineering the Demo database that gets installed with SAP SQL Anywhere 17:
The table and column names are all in UpperCamelCase. If I want to create a Logical data Model, I will need to convert them into a more human-friendly format. Out of the box, I can easily convert some standards – for example, it’s trivial to convert “SALES_REPRESENTATIVE” to “Sales Representative”. However, converting Camel Case names is not trivial. After reading a Sandhill blog entry about how to do this in ERwin yesterday, I decided to finally figure out how to do it in PowerDesigner – I’ve thought about it on and off, but never took the time to work it out. I didn’t want to do it outside PowerDesigner, as I wanted to make use of PowerDesigner’s standard naming conventions as much as possible, especially the ability to replace abbreviations with the real thing. For example, here’s part of a CSV file I was using today, which I’ll use in the next example:
I also wanted to come up with a mechanism that was as easy to use as possible – the result is a simple model extension, that adds menu options to the model, to tables, and to columns, so you can reset the names of:
For example, I have a column called “BBCOrderLn”, and want to set the Name to “BBC Order Line” – “Ln” is the abbreviation for “Line” in my CSV file. With my model extension, I just right-click the column on the diagram or in the browser, and select the option “set Proper Name”,
and the result is
Here’s a made-up example for a whole table:
How does it work? It’s based on a single model extension that contains a number of GTL templates – GTL is PowerDesigner’s Generation Template Language, which is great at turning metadata into text. One of the templates contains embedded VBScript, which is the part that does the real work. I shan’t bore you with the whole model extension here, I’ll just show you the part that converts a single column.
It includes a menu, which allows you to run the Method called “set Proper Name”, which contains a little bit of VBScript.
Sub %Method%(obj) Dim candidate candidate = obj.evaluatetemplatefor("newName","PDM-ProperCase") if not candidate = obj.Name then reportChange "Column", obj.Table.Name & "." & obj.name, obj.Table.Name & "." & candidate obj.Name = candidate ' need to change it end if End Sub
The key part here is “evaluatetemplatefor“, which runs a shared GTL template called “newName”. Because it’s shared, I only have to define it once, and then I can use it wherever I like. This is a very simple template, containing a single line of GTL, which calls the standard template (.convert_code) that PowerDesigner uses to convert codes into names, changing the case and reversing abbreviations. Instead of supplying the object code to be converted, it passes the result of the other template, “ProperCase”
“ProperCase” does the real work here, with some embedded VBscript. If you find any problems with this code, please let me know.
.vbscript(%1%) Dim obj : set obj = activeselection.item(0) Dim myString : myString = obj.Code Dim ProperCase ' converts a string into Proper Case, one character at a time ' the first character is always upper case ' if an existing character is already upper case, it is not converted ' if an existing character is a space, it is output as is ' ignore underscores - convert_code will deal with them ' acronyms are left intact ' multi-word conversions only made if they're separated by a space Dim i Dim prevSpaceInd ' was previous character a space? Dim prevUpperInd ' was previous character upper case? Dim nextChar ' the next character in the string Dim myStringLength ' the length of myString myStringLength = len(myString) Select Case myStringLength ' If there are 0 or 1 characters, just return the string. Case 0 ProperCase = myString Case 1 ProperCase = Ucase(myString) Case else ' Start with the first character - this will always be upper case ProperCase = Ucase(Left(myString,1)) prevUpperInd = true ' remember this for the next character ' Add the remaining characters Dim myChar For i = 2 To len(myString) myChar = Mid(myString,i,1) If myChar = " " then prevSpaceInd = True ' remember this for the next character myChar = " " ElseIf myChar = "_" then ' ignore myChar = myChar prevSpaceInd = True ' force script to act as if it was a space ElseIf myChar = Ucase(myChar) then ' the current character is upper case If prevSpaceInd then ' previous character was a space myChar = myChar prevSpaceInd = False ElseIf prevUpperInd then ' previous character was also Upper Case nextChar = Mid(myString,i+1,1) If i = myStringLength then ' this is the last character in the string myChar = myChar ' don't insert a space ElseIf nextChar = Lcase(nextChar) then ' next char is lower case ' If the next character is not upper case, ' assume the current letter is beginning of new word myChar = " " & myChar ' make this 1st letter of new word Else myChar = myChar ' continue an acronym End If Else myChar = " " & myChar End If prevUpperInd = true ' remember this for the next character Else ' must be lower case or perhaps a number, leave it alone prevUpperInd = False myChar = myChar End If ProperCase = ProperCase & myChar Next ' i End Select ScriptResult = ProperCase .endvbscript
Finally, you need to add a simple Global Script, which reports actions to the Output window: