validation

[bills]

Not using a list box or combo box, what is the most fundamental / simple way to validate that an entry into a transaction table ( eg. an orders table that calls for partnumber to be input ) is for an existing / valid entry in a 'master table' ( eg. an existing partnumber in a partsmaster table ).

 

[JSand42737]

Not using a list box or combo box, what is the most fundamental / simple way
to validate that an entry into a transaction table ( eg. an orders table that
calls for partnumber to be input ) is for an existing / valid entry in a
'master table' ( eg. an existing partnumber in a partsmaster table ).

Firstly, you have to do this through a form - tables in Access do not support
this sort of validation. You can then use something like the DLookup function
to check if a matching record exists:

If IsNull(DLookup("PK","tblMaster","Entry=' " & Me!txtEntry & " ' ")) Then
' Order doesn't exist
Else
' Order does exist
End If

This is checking if there is a value for PK (which is the Primary Key field, so
must always exist for each record) in the main table (tblMaster) for a record
in the Entry field that has a value equal to Me!txtEntry (the control on the
form that you entered the data into). In the above example, I am assuming that
txtEntry is a string, hence the use of single quotes - if it is numeric, then
you do not need these quotes.

 

[bills]

thanks Jon
BillS

 

[Van T. Dinh]

Enforcing the Referntial Integrity between the PartsMaster
Table and the Transaction Table. The validation will be
done by the Database Engine which is more efficient than
code.

Check Access Help / Access Book on Referential Integrity.

HTH
Van T. Dinh
MVP (Access)

-----Original Message-----
Not using a list box or combo box, what is the most

fundamental / simple way to validate that an entry into a
transaction table ( eg. an orders table that calls for
partnumber to be input ) is for an existing / valid entry
in a 'master table' ( eg. an existing partnumber in a
partsmaster table ).

 

[BillS]

thanks Van. This is indeed the most fundamental way.BillS

 

[Guest]

Jon,
I overlooked one of the most basic features - enforcing
referential integrity -> which does the validation job
quite well and simply at the table level ( see note to me
from Van T. Dinh ) thanks again.BillS

-----Original Message-----