Data Verification Data Verification and Validationand Validation

Learning objectivesLearning objectives

At the end of the lesson you will: -At the end of the lesson you will: -

Know what data verification isKnow what data verification is

Know what data validation isKnow what data validation is

Create a validation rule in a database Create a validation rule in a database tabletable

What is Data Verification?What is Data Verification?

Data verification is checking the data.Data verification is checking the data.

You must: -You must: -

Check for spelling mistakes.Check for spelling mistakes.

Check for data that has not been entered Check for data that has not been entered correctly.correctly.

Check that all data has been entered and Check that all data has been entered and nothing is missing.nothing is missing.

Why do you Check the Why do you Check the data?data?

Data Verification

Incorrect data can lead to problems, such as letters being sent to the wrong address

We all make mistakes and so its important to check.

How can you check it?How can you check it?

Reading through your records.Reading through your records.

Spell check.Spell check.

Compare your data entry sheet with the Compare your data entry sheet with the data table on your computer.data table on your computer.

Entering the data twice i.e. creating a new Entering the data twice i.e. creating a new password.password.

What is Data Validation?What is Data Validation?

The computer checks the data you The computer checks the data you enter.enter.

The computer checks if the data is The computer checks if the data is correct and makes sense.correct and makes sense.

Data TypeData Type

How?How?

List menuList menu Create a validation ruleCreate a validation rule Input maskInput mask

Validation typesValidation types

Format check – e.g. two letters followed by two numbers – PR15 would be valid but PRX71 would not.

Presence check – checking that the field contains any data.

Range check –checking that the data is between certain numbers or letters, e.g. A–E.

Lookup check – checking that only values from a set list can be entered, e.g. M or F.

Size check – checking data falls within a minimum or maximum number of characters.

Validation and Validation and VerificationVerification

SummarySummary

Verification Verification

Is done by the userIs done by the user By entering the data twice and By entering the data twice and

comparing the values entered is a comparing the values entered is a form of verification.form of verification.

Verifying that there are no spelling Verifying that there are no spelling mistakesmistakes

Correct data is entered - ie correct Correct data is entered - ie correct name, address, postcodename, address, postcode

Validation Validation

Is checked by softwareIs checked by software Is it the correct data type – date of Is it the correct data type – date of

birth in a currency fieldbirth in a currency field Would not pick up spelling mistakesWould not pick up spelling mistakes Would not detect incorrect data of Would not detect incorrect data of

the same data type being enteredthe same data type being entered