| range check |
This checks that the data lies within a specified range
of values.
Eg the month of a person's DOB should
lie between 1 and 12 |
| presence
check |
This checks that important data is actually there
and has not been missed out.
Eg Customers may be required to have
their telephone numbers. |
| type check |
A check that data is of the right type.
Eg number, text etc |
| length check |
Checks that fields have the correct number of
characters.
Eg A bank account number may always be
10 digits long. |
| check digits |
Used for numerical
data. An extra digit
is added to a number which is calculated from the other digits. The
computer checks this calculation when data is entered.
Eg The ISBN number on a book. The last
digit is a check digit. |
| batch totals |
This checks for missing
records. Numerical fields may be added together for all records
in a batch. The batch total is entered and the computer checks
that the total is correct.
Eg Add the 'Total Cost' field of a
number of transactions together. |
| hash totals |
This is just a batch total done on a meaningless
field.
Eg Add the Telephone Numbers together
for a number of Customers. |
