MS Access, Excel, SQL, and New Tables - sql

Question

I'm just starting out with MS Access 2010 and have the following setup. 3 excel files: masterlist.x (which contains every product that I sell), vender1.x (which contains all products from vender1, I only sell some of these products), and vender2.x (again, contains all products from vender2, I only sell some of these products). Here's an example data collection:
masterlist.x
ID NAME PRICE
23 bananas .50
33 apples .75
35 nuts .87
38 raisins .25
vender1.x
ID NAME PRICE
23 bananas .50
25 pears .88
vender2.x
ID NAME PRICE
33 apples .75
35 nuts .87
38 raisins .25
49 kiwis .88
The vender lists get periodically updated with new items for sell and new prices. For example, vender1 raises the price on bananas to $.75, my masterlist.x would need to be updated to reflect this.
Where I'm at now: I know how to import the 3 excel charts into Access. From there, I've been researching if I need to setup relationships, create a macro, or a SQL query to accomplish my goals. Not necessarily looking for a solution, but to be pointed in the right direction would be great!
Also, once the masterlist.x table is updated, what feature would I use to see which line items were affected?
Update: discovered SQL /JOIN/ and have the following:
SELECT * FROM master
LEFT JOIN vender1
ON master.ID = vender1.ID
where master.PRICE <> vender1.PRICE;
This gives me the output (for the above scenario)
ID NAME PRICE ID NAME PRICE
23 bananas .50 23 bananas .75
What feature would instead give me:
masterlist.x
ID NAME PRICE
23 bananas .75
33 apples .75
35 nuts .87
38 raisins .25

Answer 1

Here is a heads up since you were asking for ideas to design. I don't really fancy your current table schema. The following queries are built in SQL Server 2008, the nearest syntax that I could get in sqlfiddle to MS Access SQL.
Please take a look:
SQLFIDDLE DEMO
Proposed table design:
vendor table:
VID VNAME
1 smp farms
2 coles
3 cold str
4 Anvil NSW
product table:
PID VID PNAME PPRICE
203 2 bananas 0.5
205 2 pears 0.88
301 3 bananas 0.78
303 3 apples 0.75
305 3 nuts 0.87
308 3 raisins 0.25
409 4 kiwis 0.88
masterlist:
ID PID MPRICE
1 203 0.5
2 303 0.75
3 305 0.87
4 308 0.25
Join queries can easily update your masterlist now. for e.g.:
When the vendor updates their prices for the fruits they provide you. Or when they stop supply on that product. You may use where clauses to add the conditions to the query as you desire.
Query:
SELECT m.id, p.vid, p.pname, p.pprice
FROM masterlist m
LEFT JOIN product p ON p.pid = m.pid
;
Results:
ID VID PNAME PPRICE
1 2 bananas 0.5
2 3 apples 0.75
3 3 nuts 0.87
4 3 raisins 0.25
Please comment. Happy to help you if have any doubts.