Calculated fields?

[crcastilla]

Hello,

So I'm wondering how to do the following:


Let's say I have a the quantity of 180 and i have two kinds of tables (round and square) they are on my related table as you can see. I want it so when I change the quantity of round tables or square tables it will also change on my the main quantity of tables. Also I want to create a new field that shows the quantity that is "out". So let's say I have 100 round tables and I change it to 50. It will automatically take off 50 of the round tables and of the main table quantity. Same thing would have to work for each item like chairs, hats, etc.
I don't know if I explain myself. I don't know if it is complicated to do this. Please anyone help :/

[crcastilla]

there is an attached file there of how the tables are set up without any calculated fields. They are just tables in a one-many relationship

[orange]

Do NOT store calculated fields in tables.