I am pretty new to access and have a question which I will try to explain and hope it makes sense. I'll give a bit of background as to what im doing and what my issue is.
BACKGROUND - I have a source system which is a seperate access database which is my 'source' system. I have a seperate access database which daily runs a query against the source system and populates it to a table in my application called tblAud_Current. I then compare tblAud_Current to tblAud_Compare (this is yesterdays data) and any changes i identify by using the primary key and then verifying each individual field and that they match. This seems to be working ok. If they dont match it inserts the old and new value into tblAud_logs
ISSUE - The issue that I have is getting my extract of source data so as that there are only 1 unique record to be able to compare. In the source system there is a table called tblContract. This contains fields such as name, address, contractno, mailaddress etc. There is another table called tblContractRate which contains fields such as contractno (this is the link field) ,ratefrom, rateto . This table could contain more than one rate for a contract e.g for 2007, 2008 and 2009. This is where my problem is because when I do the join I end up getting mulitple records in my tblCurrent. Then when I compare it will show that the records have changed yet they may not have. If i dont extract the contract rate I have no issues
I have below copied my query which is to get the data out of the source and insert it into the tblAud_Current table.
I have then copied example code which compares the field Customer Name... I have one of these queries for each field I need to check.
I have attached result of the query (selected only first 20 records) and as you can see my problem of mulitple records due to the rates issue.
I am sorry if this is extremely long I have been stuck on this for quite some time and have no way forward. I am more than happy for any suggestions even if it means changing my approach.
Thanks heaps assistance greatly appreciated. Please let me know if this isnt clear or you need it simplified or more specific detail.
INSERT INTO tblAud_Current ( ContractNo, MIRN, CustName, ServiceAddress, ContractStartDate, ContractEndDate, DeenergDate, MailAddress, RateFrom, RateTo, ContractPeakRate, DefaultTariffId, Phone1, Phone2 )
SELECT tblContract.ContractNo, tblMIRN.MIRN, tblContract.CustName, tblMIRN.ServiceAddress, tblContract.ContractStartDate, tblContract.ContractEndDate, tblContract.DeenergDate, [MailAddress1] & " " & [MailAddress2] & " " & [MailLocality] & " " & [MailState] & " " & [MailPostcode] AS MailAddress, tblContractRate.RateFrom, tblContractRate.RateTo, tblContractRate.ContractPeakRate, tblContract.DefaultTariffId, tblContract.PhoneNo_1 AS Phone1, tblContract.PhoneNo_2 AS Phone2
FROM ((tblContract INNER JOIN tblContractMIRN ON tblContract.ContractNo = tblContractMIRN.ContractNo) INNER JOIN tblMIRN ON tblContractMIRN.MIRN = tblMIRN.MIRN) INNER JOIN tblContractRate ON tblContract.ContractNo = tblContractRate.ContractNo
WHERE (((tblContract.DeenergDate) Is Null));
EXAMPLE COMPARE QUERY.....
INSERT INTO tblAud_Logs ( MIRN, OLD_VALUE, NEW_VALUE, FIELD_MODIFIED )
SELECT tblAud_Compare.MIRN, tblAud_Compare.CustName AS OLD_VALUE, tblAud_Current.CustName AS NEW_VALUE, 'Customer Name' AS FIELD_MODIFIED
FROM tblAud_Compare LEFT JOIN tblAud_Current ON tblAud_Compare.MIRN = tblAud_Current.MIRN
WHERE ((( tblAud_Compare.CustName)<>[tblAud_Current].[CustName]) OR (tblAud_Compare.CustName IS NULL AND tblAud_Current.CustName IS NOT NULL) OR (tblAud_Compare.CustName IS NOT NULL AND tblAud_Current.CustName IS NULL));