How to Model Database Views

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Tim Smith

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Sep 6, 2022, 6:27:18 PMSep 6
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Hi,

I am attempting to capture database views in EDG.  In particular, I want to be able to capture derived columns and how those columns are derived.  e.g. view column  A is the sum of table 1 column B and table 2 column C.

Looking at Database View, I see view input column and view output column.  There are no descriptions so I can only infer that these property shapes are used to define the columns of the view  (output) and what columns are referenced to create the view (input)?  Correct?

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However, what I need is column to column(s) mapping.  Digging deeper by looking at Database Column, I see inferred Referenc-ed/ing Columns.  It is not clear if I am to use edg:parentColumn and edg:childColumn properties to establish the relationships between columns that are transformed to become a column in a view nor how I would do this. (see screenshot below)

Do you have any examples?  It would be great if the example graphs for EDG could be expanded to include examples that fully populate all EDG classes and property shapes across all asset collections.  The ontological structure is not always intuitive at takes considerable time to discover how to do things.

Thanks in advance for your help,

Tim


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Tim Smith

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Sep 8, 2022, 4:31:59 PMSep 8
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As an additional data point regarding edg:DatabaseView, there is no property shape declared that displays the columns of the view on the form.  Database Table has  edg:DatabaseTable-columnOf-inverse to show the columns in the table. 

Following up on my original question in this thread, am I supposed to use the view input column and view output column property shapes to attach and display the columns in the view?  When importing views via DDL, the importer uses edg:columnOf to link a column to the view.    Should I add a new property shape using edg:columnOf?

Tim

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Tim Smith

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Sep 14, 2022, 12:59:37 PMSep 14
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Can anyone at TQ explain how to properly use the Database View class?  There are so many classes and properties without descriptions, let alone fully-populated examples that I spend too much time trying to figure out how to use the ontologies.  I'm close to abandoning the pre-built ontologies and building my own.  Then I can downgrade my license to only ontologies and data graphs ;)

There is little value in a product that provides extensive ontologies but does not provide the knowledge to use them.  And no - I'm not a novice in this space.  I've been building and using ontologies since 1998 and I was the first customer to purchase TBL years ago.
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