How to Build a Business Rules Engine

Prevention of Duplicate Records 359

LISTING 17.1

Fragment of Generated Code for Detection of Duplicate Records

' Section 4: Check for Duplicate Records

' Check for duplicates in Table Investment

' —INV_INVESTMENT_S

' Primary Key Column: Investment ID (INV_C)

strSQL = "SELECT * FROM INV_INVESTMENT_S WHERE INV_C = '" &

frmMe.INV_C & "'"

If Not IsNull(frmMe.RECORD_ID_C) Then

strSQL = strSQL & " AND RECORD_ID_C <> " &

CStr(frmMe.RECORD_ID_C)

End If

rstSource.Open strSQL, CurrentProject.Connection, _

adOpenKeyset, adLockOptimistic, adCmdText

If Not rstSource.EOF Then

intErr = intErr + 1

strErr = "A record already exists for this Investment ID

(Error Code: R0052)"

End If

rstSource.Close

' Check for duplicates in Table Investment

' —INV_INVESTMENT_S

' Primary Key Column: ...