Data validation Flashcards
What is data validation?
Data validation is checking, carried out by the computer to make sure that input data are within the limits of what a user might reasonably enter.
Name 5 types of data validation.
Any 5 from: Type check, range check, limit check, length check, character check, format check, presence check, consistency check or check digit.
What is consistency check?
In a consistency check the software checks that different fields in the same record correspond correctly. For example if ‘Ms’ has been entered into the title field, ‘Female’ must be entered into the gender field.
What is presence check?
In a presence check, the software checks that essential data items have been entered when the current record is entered or ‘submitted’. For example, when applying for a service on a form on a web page you are usually required to supply certain minimum information, even if some fields remain optional.
What is type check?
Type check is when the program expects to receive data of a partiular type, it automatically rejects characters or symbols entered that are inconsistent with the type of data. For example, the characters ‘0’ to ‘9’ and ‘.’ will be acceptable for a decimal number, but ‘J’ and ‘#’ will not be.
What is range check?
In a range check, the software checks that a numerical value is within a particular range of values. For example, the validation rule might be that a number must be greater than zero and less than or equal to 100.
What is limit check?
A limit check is similar to a range check, but the rule involves only one limit. For example, a number might be limited to being greater than or equal to zero.
What is length check?
In a length check, the software checks that the number of characters entered in a string is within specified limits. For example, we can use a length check to enforce a minimum of six characters when setting a password.
What is character check?
In a character check, the software checks that a string of charcaters does not contain invalid characters or symbols. For example, when registering a birth, a parent is likely to be restricted to alphabetic characters for the baby’s registered name.
What is format check?
In a format check, the software checks that a string of characters has the required pattern or ‘format’. For example, an ID code may be required in the format ‘LLL000000’, meaning three letters followed by six digits.
What is check digit?
Check digit is an extra digit that is calculated from all the original digits in order to summarise them.
