Update Query From 3 Tables

[eyeseven]

hi..

i need help with one of my tables.

tbl_type1
-type1_id
-PONumber

tbl_type2
-type2_id
-PONumber

tbl_bill
-billID
-PONumber
-bill_type

Now I have huge data from tbl_bill which contains mix PONumber depends on type. If bill_type is type1 then it will get data from tbl_type1 table and vise versa.

the problem is tbl_type1 and tbl_type2 is changing, when someone update this table then the data in tbl_bill will not match to 2 tables.

Now, i need an update query where I can update all records of tbl_bill to match with tbl_type1 and tbl_type2 PONumber.

I hope someone can help me solving this problem.

Thanks so much!

 

[jdraw]

Please describe the "business" issue in plain, simple English. What is the database about?

 

[eyeseven]

Main functions of this database is for Simple Project Management,

I Have 3 Tables, Project,Variation and Billing Table. These two tables are one to many relationship. Project to Many Variation.

Project and Variation Record has its own PO Number.

Now I've created a bill form which automatically copy PONumber from two different table depends on type selected in combobox.

The problem is when Projects or Variatino PO Number change, then Bill PONumber will not match, and I need to go record and update.

Check attaached Access File.

 

[jdraw]

I don't think you have a clear understanding of the business issue.
Many project management systems involve

Projects
Tasks
Resources
-human
-skills
-roles
-material
Time
-estimated
-actual
Location
Customer

but you know your requirements better than readers do.

Here's a generic data model for consideration: