Visualizing Merge Join Types in Power BI 07-26-2017 19:48 PM

[SqlJason]

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.

eyJrIjoiYmNhNzgzYjAtNjc2OS00YjQwLTgwNzItM2Q1MzcyMmJlYjMyIiwidCI6IjZjMGE1YjljLTA4OWEtNDk0ZS1iMDVlLTcxNjEwOTgyOTA0NyIsImMiOjF9

[Anonymous]

Hi Jason,

I expanded on your sample and I notice that when you do Cross Join it show correct value in power query (5x4=20)
But when you try to show in power bi table visual you get only 15 records (5x3) ?
How do you correct that? see attachments

Thanks,

Oded Dror

[Anonymous]

Jason,

Please Discard the previous question I fix it

Thanks,

Oded Dror

[Anonymous]

Good Job!

[ketan10]

This is pretty interesting @SqlJason ! Good work.

[deldersveld]

Are you using the Visio custom visual for the main join diagram?

[SqlJason]

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.

[deldersveld]

Thanks. I see Synoptic's zoom control now. I haven't spent any time with the Visio preview.

[leonardmurphy]

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).

[SqlJason]

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.