Azure-devops-docs: What are the "tables" available and how do you join them?

[StingyJack]

Most of these examples use [Workitems] but there is also a [WorkItemLinks]. What other tables are available?

Also I think I was able to join these two tables/sets several years ago but I dont remember if thats true, and if so, how I did it. Is this possible to query for workitems and use filter criteria for both sets at the same time?

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Document Details

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• ID: 710af5f2-8a31-e0d3-4f20-00c79dc54713
• Version Independent ID: 1d4d9580-984c-9fee-861a-a02ce828d3db
• Content: WIQL reference syntax - Azure Boards
• Content Source: docs/boards/queries/wiql-syntax.md
• Product: devops
• Technology: devops-agile
• GitHub Login: @KathrynEE
• Microsoft Alias: kaelli

[jeroenhabets]

Or even just answerring: Can you join [Workitems] and [WorkItemLinks].
Use-case: need to retrieve _diverse_ but small list of Features including the ID of the Parent Epic.

[KathrynEE]

@jeroenhabets - The Queries editor and WIQL syntax don't really work with the concept of Joining tables. The data warehouse tables are documented here for the SQL Reporting purposes: https://docs.microsoft.com/en-us/azure/devops/report/sql-reports/work-item-history-tables?view=azure-devops-2019.

If you have more advanced query needs, you might consider using the Analytics service which is the new reporting data service implemented for Azure DevOps 2019 and Azure DevOps Services. The data model is documented here: {Data model](https://docs.microsoft.com/en-us/azure/devops/report/extend-analytics/data-model-analytics-service). I believe you can retrieve the data you are looking for using Power BI and either an Analytics view or OData query.

[StingyJack]

@KathrynEE - what about my question(s)?

[KathrynEE]

@StingyJack - Apologies for not addressing your question. The data warehouse tables pertaining to work items are:

• Work item History tables
• Work Item Link History tables
• Work Item Category tables
• Work Item Test Result tables
• Work Item Changeset tables

You can't join tables via a query. The query editor provides support for querying based on link relationships. Within that query, you can specify clauses to filter based on the linked work items. So in that sense, yes, you can use filter criteria for both sets.

Also I think I was able to join these two tables/sets several years ago but I dont remember if thats true, and if so, how I did it. Is this possible to query for workitems and use filter criteria for both sets at the same time?