Work smarter with #PowerDesigner – Choosing your Conversion Table

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:

  • near the bottom of the Tools menu
  • right-click the model in the Browser
  • right-click a blank area of a diagram

Click on the “Naming Conventions” section, then on the “Code to name” sub-tab, as shown below.  You need to do two things:

  1. Select “Enable conversions”
  2. Choose from the drop-down list of conversion tables – in the example below, I’ve chosen one of my CSV files

PDM model options - conversion table

The drop-down list of conversion tables will include entries from the following sources:

  • if you have a repository, one entry for ‘glossary terms’ (these are the Terms in the PowerDesigner Glossary)
  • CSV files that have been checked into the ‘Library’ folder in the repository
  • CSV files in the target folder(s). Click on the folder icon to the right of the drop-down to change the target folders – the default folder is “C:\Program Files\SAP\PowerDesigner 16\Resource Files\Conversion Tables”, which contains a single sample, called “stdnames.csv”, so you’ll probably want to add at least one more folder to the list.

You can edit your conversion table directly, without using Excel – just click on the ‘Edit Selected Conversion Table’ button.

edit selected conversion table

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:

naming for columns

So, you could use different conversion tables for different types of object, if you want to.

Work smarter with #PowerDesigner – Converting Camel Case Codes to Mixed Case Names

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:

att names and codesAs 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.

att names and codes 2

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:

 

SQL Any 17 Demo DB

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:

abbrevsI 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:

  • all tables and columns in the models
  • a selected table
  • all the columns in a selected table
  • a selected column

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”,

column Proper

and the result is

column Proper after

Here’s a made-up example for a whole table:

Proper 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 VBScriptxem proper column.

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.proper shared templates 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”

.convert_code(%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:

reportChange

Work smarter with #PowerDesigner – adding a sub-Requirements tab in the RQM

The PowerDesigner Requirements Model (RQM) is a powerful tool for managing requirements, or anything else you want to keep track of that has a hierarchical structure but doesn’t fit well with any of the other PowerDesigner Models.

For example, take a look at a sample RQM supplied by SAP, in the WebLibrary project, which is usually installed at “C:\Program Files\SAP\PowerDesigner 16\Examples\WebLibrary\WebLibrary.prj“. Here we can see a simple hierarchy of Requirements in the Browser:01 WebLibrary RQM - browser

The same hierarchy is also visible in a Requirements Document view, like this one:02 WebLibrary RQM - requirements document view

However, when I’m editing a Requirement via the properties dialogue, I can’t see a list of sub-Requirements. That means I have to use the Browser or a Requirements Document View to work on the sub-Requirements. Most of the time, I’d like to work in a spreadsheet-like view, the same as in any other type of model in PowerDesigner, like this list of Columns in a Table:

List of Columns

I can’t access a list of Requirements via the Model menu, so it doesn’t look like I can use my favourite editing approach – or can I?

The answer is that I can work on such a list – with a very simple model extension, I can add a ‘Sub-Requirements’ tab to the Requirement editor, like this one:

03 WebLibrary RQM - sub-reqs tab

Like any other list of objects in PowerDesigner, I can filter this list, edit single entries, edit multiple entries, change the sequence, and create new entries.

So, how is this possible? Simple, I exposed the existing collection of sub-Requirements on the new tab, by creating a new Form in a model extension.

04 Model Extension

This isn’t the place for detailed instructions for creating an extension, so I’ll limit this to a few pointers for you:

  • “Requirement” is a Metaclass
  • You can call the Form anything you like
  • “Requirements” is a Collection, not an Attribute

There are probably other areas in PowerDesigner where this technique is useful, let me know if you find one.

Work smarter with #PowerDesigner – How to display a ‘Relationships’ tab for entities

Data modelling tools vary in the kinds of dependencies that you can create between objects. For example, they all recognise that entities in a Conceptual or Logical Data Model (CDM or LDM) can participate in Relationships – when you view or edit the properties of an entity most (perhaps all) tools will show you a list of relationships as part of the dialogue. They might also show you other dependencies, such as a list of diagrams the entity appears on, a list of related tables in Physical Data Models, or some Data Lineage or other mappings. With most tools, that’s the limit. PowerDesigner goes beyond these basic modelling and development connections, allowing you to create several other different types of dependencies:

  • shortcuts – the entity is used in another model, but cannot be amended
  • replications – the entity is used in another model, and can be amended, subject to limitations
  • traceability links – the entity can be connected to virtually anything else in any type of model, if it makes sense to you
  • related diagrams – the entity can be connected to a diagram in any type of model, if it makes sense to you
  • extended collections – using a model extension, you can create your own links between entities and other objects

One side-effect of this power and flexibility is the impact on the entity properties dialogue – most of these dependencies are all shown on the same tab. In the example below, the Contribution entity participates in four relationships, listed on a sub-tab; I can see that the entity also appears on at least one Diagram (indicated by the presence of the Diagrams sub-tab). There could be more tabs, if the entity has other types of dependencies.

dependencies

If you’re used to other data modelling tools, you might prefer to see relationships listed in a tab of their own. Well, with a little work, you can add that tab for yourself; you just need a simple model extension.

You create or use Model Extensions to change the way that PowerDesigner works, usually by adding additional metadata, or additional features such as imports, exports, and new object properties. In this example, we’re not adding a new feature, merely exposing some metadata – the Relationships collection – that already exists.

You may already have one or more extensions attached to your model, such as the Excel Import extension, but I’ll assume that you don’t.

  • On the Model menu, select Extensions
  • Create a new entry in the list – just type the name – then click on OKadd extension
  • The new extension will appear in the Browser

extension in Browser

  • Double-click the extension to open it, then right-click Profile, and add the Entity metaclass to the extension

 

  • Add a new Form to the metaclass, call it Relationships

add form

  • Add the Relationships collection to the Form, then close the extension editor
  • Here’s the new tab

the new tab

It’s possible to add more than one collection to a Form, plus lots of other things; I’ll cover these in future tips.