Intelligent Comparison based Update - Access / VBA -

need intelligently perform updates on access table. expert vba / intelligent thinking required.

table1 (for reference only) companycode     text regioncategory  number (1-99) regioncount     number(0 - 25000)  table2 invoicenumber       number companycode         text     numrows             number regioncode          fourdigitnumber confirmationremark  y / n 

ourobjective put yes or no in 'confirmationremark' column. rules :

1.select invoicenumbers have 2 rows table2 , different regioncode. these have same companycode. regioncategory first 2 digits of regioncode.

2.for these 2 invoices - difference between 2 regioncategory must greater two.

3.lookup regioncount , table1

decision making : comparing 2 invoices different regioncodes. idea , invoice higher regioncount 1 marked yes.

1.the difference between regioncount must considerable. 'considerable' - trying determine right number. let take 500 now.

2.the invoice lower region count - should have regioncount - 0 (bestcase) or very low. if invoice lower region count has high regioncount value > 200 , cannot conclude.

3.numrows , prefered 1 or lesser other. comparison , not mandatory , hence shall have provision not check this. mark other invoice 'n'

you have many ways approach type of complex update.

if lucky, may able craft sql update statement can include changes, have resort combination of select queries , custom vba filter them based on results of calculations or lookups involving other data.

a few hints

• often, tend think problem in terms of 'what steps data match criteria'.
  sometimes, though, it's easier turn problem on head , instead ask 'what steps data not match criteria'.
  because in case result boolean, true or false, set confirmationremark field true records , update should set false, instead of other way around.

• break down each step (as did) , try find simplest select query return data need step. if step complex, break down further.

• compose broken down select statements build more complex query tends toward goal.

• once have gone far can, either construct update table2 set confirmationremark=true invoicenumber in (select invoicenumber ....) or use vba go through recordset of results complext select statement , more checks before update field in code.

some issues

unfortunately, despite efforts document situation, there not enough details help:

• you not mention primary keys (from say, seems table2 have multiple records identical invoicenumber)

• the type of data dealing not obvious. should include sample of data , identify ones should end-up confirmationremark set.

• your problem localised, meaning specific of value else, although think bit more details question of interest, if show example of how approach complex data updates in access.