Validation and Verification : Table Lookup Check

Validation and Verification : Table Lookup Check

Sometimes when you enter a data item into an information system the item should only be one of a list of possible items. For example :

Gender	When entering the gender of a person into a database the only two valid entries could be Male and Female.
Membership Number	When entering a membership number into a database the membership number must be a number that actually exists and belongs to a member.

When this is the case a table lookup check can be used. A table lookup check takes the entered data item and compares it to a list of valid entries that are stored in a database table. If the entry is in the list of valid entries then it is allowed. Otherwise it is rejected.

Table lookup checks are also known as membership list checks or file lookup checks.

GCSE ICT Companion 04 - (C) P Meakin 2004