Visualizing Merge Join Types in Power BI
07-26-2017 19:48 PM
07-26-2017 07:48 PM
You can combine two queries in Power BI using the Merge Queries option (in Edit Queries). While merging queries, you will be asked for a join kind. This report visually shows what are the different join kinds as well as show the resulting merged table.
07-26-2017 08:52 PM
Synoptic Panel. Just made a simple png using PowerPoint and then used the Synoptic Designer to create the 3 areas within the Venn chart.
I initially thought of using the Visio custom visual, but then remembered that you will need to make the visio file public with everyone to publish this report to the web. This visual requires One Drive for Business (so I don't have a personal account) and right now, my company does not allow sharing files publicly. So could not use the Visio option.
07-27-2017 11:46 AM
Nice work Jason (and great idea too)!
I haven't seen anything explaining joins as simple to understand as your diagram on page 2. As much as the Venn diagram is a classic, the blocks were as straightforward as side-ways Tetris to me (seeing which blocks "fall" to the right-hand column based on their presence and/or absence in the other 2 columns).
Cross joins might be worth adding to the mix (but that would not be fun to do).
07-27-2017 12:38 PM
Thanks Leonard, though I can only take the credit for developing the actual solution. The join diagrams are inspired from this post - https://blog.jooq.org/2016/07/05/say-no-to-venn-diagrams-when-explaining-joins/ and was pointed out to me on twitter by @@thesqlgrrrl.