Question

I am using MS Access 2007.

I am collecting data of different types of businesses within a town area, arranged by streets, the business.

In TableA, I have a list of different specific streets, no duplicates, field: Street; and another, field: NumOfBusinesses.

In TableB, I have a list of different specific businesses, Business; and what street they are on, Street.

eg

TableA

STREET..................NUMOFBUSINESSES

High Street
Sheep Street
Silver Street
Gold Street

TableB

BUSINESS................STREET

McD's                    High Street
Hair Dresser             High Street
Shoeshop                 Gold Street

What I want to be able to do, is count the amount of business per street from TableB and add that into the TableA, corresponding to each street.

I have over 600 streets, so I don’t want to have to manually go through each individual count and add it in manually.

Is there a type of query I can use, or even code I could put in as the default value of the “Num…sses” field, so it dynamically changes the query depending on the relevant street in the record?

So in essence, I want TableA to look like this automatically

TableA

STREET..................NUMOFBUSINESSES

High Street             2
Sheep Street            0
Silver Street           0
Gold Street             1

Answer 1

You can get the results from a query, so do you really need to update a field?

SELECT Tablea.Street, Count(Business) 
FROM TableA 
INNER JOIN Tableb
ON TableA.Street = TableB.Street
GROUP BY Tablea.Street

It is not usually recommended that you store calculated data.

If you really must store the count, you can say:

UPDATE tablea 
SET numofbusinesses=
   DCount("*","tableb","street='" & Replace(street,"'","''") & "'")
WHERE Street Is Not Null