Joint question

[Anzek]

Let say we have tables A, B, and C.
A left join B with key = invoice number ( A<---B).
B right join C with key = supplier code ( B---->C).

What does the result look like?

field1: A's invoice number
field2: some field from B that matches A's number and C's code?
field3: C's supplier code

But what about those records where no invoice number is found in B and/or no supplier code is found in B? Do they show up too? but with blank fields for invoice number and supplier code?

Thanks for reading my question!

 

[Joe4]

But what about those records where no invoice number is found in B and/or no supplier code is found in B? Do they show up too? but with blank fields for invoice number and supplier code?

Yes. It appears the "B" here is your main controlling table (as you have the arrows starting from B and pointing to the other tables).
So, without any criteria, that would return ALL the records from Table B, and just the matches from Tables A and C. If there is no match in those tables, it will return a NULL value (which will look like a blank).
If you want to fill those NULL fields with some default value in the case where there is no match, you can use the NZ function.
See: https://www.techonthenet.com/access/functions/advanced/nz.php

 

[Anzek]

Sorry I'm an Access noob.
My arrows represent the real arrows in Access pointing from B to A and then B to C. I thought it means A left join B ( returning all from A and only those that match from B), and B right join C ( return all from C and only those that match from B). Is B still the controlling table?

 

[Joe4]

My arrows represent the real arrows in Access pointing from B to A and then B to C. I thought it means A left join B ( returning all from A and only those that match from B)

Nope. You have it backwards. If the arrow is pointing FROM B to A, then it is B Left Join A (returning all records from B and only those from A that match).

By the way, you actually do not need to remember this. Access will tell you.
If you open you query, and double-click on the Join line, Access will tell you exactly what it means.