Choosing a validation check for each field

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which validation check best fits a Mark field that must be between 0 and 100?

A Range check

B Presence check

2. A PhoneNumber field must always contain exactly 10 digits. Which check fits best?

A Length check

B Range check

3. The FirstName field must not be left empty when a new student is added. Which check fits best?

A Length check

B Presence check

4. A YearGroup field may only contain 7, 8, 9, 10 or 11. Which check fits best?

A List check

B Presence check

5. An Age field for students in a school must be between 11 and 18. Which check is the best choice?

A List check

B Range check

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1Range check: Mark >= 0 AND Mark <= 100		AA length check tests the number of characters, so it cannot stop 3 or 14 being entered. A list check against the valid year groups is better.
2Length check: LENGTH(Phone) = 11		BYearGroup IN (7, 8, 9, 10, 11)
3A Name field is required, so the record must not be saved with it empty. Use a presence check.		CChecks the data has exactly the right number of characters, so it fits a phone number
4A YearGroup field can only hold a few fixed values, so check it against an allowed list.		DA presence check only confirms that something was typed, so it would accept a mark of 500. A range check from 0 to 100 should be used.
5Validation for Mark: presence check		EChecks a number lies between a lowest and highest allowed value, so it fits a test mark or an age
6Validation for YearGroup: length check		FName <> ''

Definitions

validation check

Fill in the Blanks

Complete each line of code by filling in the missing parts.

Mark: _____ check, between 0 and 100

Phone: ______ check, must be 10 characters

FirstName: ________ check, cannot be empty

YearGroup: ____ check, only 7, 8, 9, 10, 11

IF ______(Phone) = 10 THEN ACCEPT

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A Field: Mark (integer)

B Check: length check

C Rule: 0 <= Mark <= 100

Question 2

A IF LEN(Phone) = 11 THEN

B OUTPUT "Must be 11 digits"

C ENDIF

Question 3

A Field: FirstName

B Check: presence check

C Rule: FirstName = ""

Question 4

A Field: YearGroup

B Check: presence check

C Rule: IN (7, 8, 9, 10, 11)

Question 5

A Field: Age

B Check: length check

C Rule: Age >= 11 AND Age <= 16

D Reject if outside range

Answer Key

Choosing a validation check for each field

Section A: Quick Questions

A — Range check

A — Length check

B — Presence check

A — List check

B — Range check

Section B: Match the Pairs

Range check: Mark >= 0 AND Mark <= 100 → Checks a number lies between a lowest and highest allowed value, so it fits a test mark or an age

Length check: LENGTH(Phone) = 11 → Checks the data has exactly the right number of characters, so it fits a phone number

A Name field is required, so the record must not be saved with it empty. Use a presence check. → Name <> ''

A YearGroup field can only hold a few fixed values, so check it against an allowed list. → YearGroup IN (7, 8, 9, 10, 11)

Validation for Mark: presence check → A presence check only confirms that something was typed, so it would accept a mark of 500. A range check from 0 to 100 should be used.

Validation for YearGroup: length check → A length check tests the number of characters, so it cannot stop 3 or 14 being entered. A list check against the valid year groups is better.

Section C: Definitions

validation check — A rule that tests data on entry. Pick the one that fits each field: range for a mark, length for a phone number, presence for a required name, list for a year group.

Section D: Fill in the Blanks

Mark: range check, between 0 and 100

Phone: length check, must be 10 characters

FirstName: presence check, cannot be empty

YearGroup: list check, only 7, 8, 9, 10, 11

IF LENGTH(Phone) = 10 THEN
  ACCEPT

Section E: Spot the Error

B — A mark is a number that must fall between limits, so it needs a range check. A length check counts characters and does not test the size of a value. It should be 'Check: range check'.

A — A length check should reject a phone number whose length is wrong. Using = would show the error for valid numbers. It should be IF LEN(Phone) <> 11 THEN.

C — A presence check makes sure a required field is not empty. Using = "" would only accept an empty name. The rule should be FirstName <> "".

B — A presence check only tests that something was entered, so a wrong year such as 12 would still pass. A year group must be one of a fixed set of values, so use a list check.

B — The rule tests that Age lies between 11 and 16, which is a range check. A length check only counts characters, so it would accept an age such as 99. It should be 'Check: range check'.