Access Level Three

[Functions] & “ And “ & [Expressions]

DateDiff ( interval, date1, date2)

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Numbers For ArgumentsThe Int function returns the integer portion of a number.The syntax for the Int function is:Int ( arguments )

Int (210.67) would return 210Int (2.98) would return 2Int (-2.98) would return -3

The Round function returns a number rounded to a specified number of decimal places. Round (12.55, 1) would return 12.6 (rounds up)Round (12.65, 1) would return 12.6 (rounds down)Round (12.75, 1) would return 12.8 (rounds up)

Text For ArgumentsThe Len function returns the length of the specified string.

Len ("techonthenet") would return 12.Len ("Wednesday") would return 9.Len ("apple pie") would return 9.

The Asc function returns the NUMBER code that represents the specific character.

Asc ("W") would return 87.Asc ("Wednesday") would return 87.Asc ("x") would return 120.

Numbers and Text For Arguments

The DateAdd function returns a date after which a certain time/date interval has been added.

•DateAdd ('yyyy', 3, #11/22/2003#) would return ’11/22/2006‘

•DateAdd ('q', 2, #11/22/2003#) would return ’05/22/2004‘

•DateAdd ('m', 5, #11/22/2003#) would return ’04/22/2004‘

•DateAdd('yyyy', -1, #11/22/2003#) would return ’11/22/2002'

Field Names As Arguments

Int ([Salary] + [RaiseAmount])

AVG([RaiseAmount])

Iff ([Salary] + [RaiseAmount]< [Salary Cap], [Salary] + [RaiseAmount], [Salary Cap])

Functions As Arguments(Nested Functions)

Int (Iff ([Salary] * .5 > 100000, [Salary] * .25, [Salary] * .35))

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The DateDiff Function

•The DateDiff function returns the difference between two date values, based on the interval that you specify.

•The syntax for the DateDiff function is:

•DateDiff ( interval, date1, date2, [firstdayofweek], [firstweekofyear])

•interval is the interval of time to use to calculate the difference between date1 and date2.(see next slide)

•date1 and date2 are the two dates to calculate the difference between.

http://www.techonthenet.com/access/functions/date/datediff.php

Valid Intervals for DateDiff

Interval Explanation Interval Explanation

yyyy Year w Weekday

q Quarter ww Week

m Month h Hour

y Day of Year

n Minute

d Day s Second

All values must be enclosed in quotes in the function.

The IFF Function•The IIF function returns one value if a specified condition evaluates to TRUE, or another value if it evaluates to FALSE.

•The syntax for the iif function is:•iif ( condition, value_if_true, value_if_false )

•condition is the value that you want to test.

•value_if_true is the value that is returned if condition evaluates to TRUE.

•value_if_false is the value that is return if condition evaluates to FALSE.

The IFF Function

iif ([Qty] > 10, "large", "small")…would return…

"large" if the value in the Qty field is greater than 10

“small” if the value is 10 or less

The Function…

The IFF Function – Nested IFF

iif ([Qty] > 100, "large", iff([Qty]>50, medium”,"small"))

This function would return…Large if Qty is 101 or greaterMedium Qty is between 51 and 100Small if Qty is 50 or less

The INT Function

•The Int function returns the integer portion of a number.

•The syntax for the Int function is:•Int ( expression )

•expression is a numeric expression whose integer portion is returned.

The INT Function

Examples

•Int (210.67) would return 210•Int (2.98) would return 2•Int (-2.98) would return -3

•Note: If the expression is negative, the Int function will return the first negative number that is less than or equal to the expression.

The SQR Function•The Sqr() function is used to calculate the square root of a double-precision number.

•Its syntax is:

•Sqr(number)

•This function takes one argument and it must be a number. After the calculation, the function returns the square root of the number.

The SQR FunctionExamples:

sqr(100) returns 10

sqr(25) returns 25

sqr(55) returns ?

sqr([total]) returns the square root of the value

being stored in the field named total

The LEN Function•The Len function returns the length of the specified string.

•The syntax for the Len function is:

•Len ( text )

•text is the string to return the length for.

The LEN Function

Examples:

Len ("techonthenet") would return 12

Len ("Wednesday") would return 9

Len ("apple pie") would return 9

Len (“”) would return 0

Note: the text string must be enclosed in double quotes, especially if it contains a space or any special characters.

The & Operator

Used to concatenate multiple Used to concatenate multiple strings into a single stringstrings into a single string

string_1 &  string_2 &  string_n

Example:"new" & "ark“

would return "newark“

"Tech on the" & " Net!“would return "Tech on the Net!“

"This " & "is " & "a test“would return "This is a test"

Text must be enclosed in double quotes. You can concatenate field names text strings or expressions

Double Declining Balance (DDB)

Used to calculate the depreciating value of an asset

The syntax is…

DDB(cost, salvage, life, period)

DDB($15000, $1200, 4, 3)

DDB([OriginalPrice], [EOL-Value], [HowLongIWillKeepIt], [Now -

PurDate]

Double Declining Balance (DDB)

Cost = How much you paid for it

Salvage = How much it is worth at the end of its useful life

Life = How long the item will last, the useful lifetime of the item

Period = The year* for which you want to calculate depreciation for a given item.

DDB(cost, salvage, life, period)

* If an item has a life of 5 years, you can calculate depreciation for the first year (1), second year (2), third year (3), etc.

Age: IIf(DateDiff("yyyy",[PurchaseDate], Date()) > [Lifetime], "Too Old", DateDiff("yyyy", [PurchaseDate], Date()))

CurrYearDepreciation: IIf([Age]="Too Old", 0, DDB([PurchaseValue], [SalvageValue],[Lifetime],[Age]))

The PMT Function

•The PMT function calculates the total monthly (or other period) payment (principal + interest) for any given loan amount

•The syntax for the PMT function is:•Pmt(Rate, NPeriods, PresentValue, FutureValue, PaymentType)

The PMT Function• Rate is the interest rate per period

– 5% annual interest rate = 5%/12 for monthly payment

– 5% annual interest rate = 5%/6 for bi-monthly payments

– 5% annual interest rate = 5%/2 for semi-annual payments

• Nper is the number of periods– For a 10 year loan…

• The Nper is 120 if you are making monthly payments on the loan

• The Nper is 10 if you are making annual payments

The PMT Function• PV is present value, the amount of the

loan (after down payment)– If you are borrowing money, this value should

be negative– If you are collecting money (you loan money

to another person) this value should be positive

• FV is future value, the balance after the last payment– This argument is optional. If it left blank

Access assumes 0.

• Type or Due determines when payment is due. – 0 = End of the Month – 1 = Beginning of the Month– Argument is optional

The PMT Function• Examples

– Pmt(12.5%, 28, $1450, 0, 1) = -$59.97

– Pmt(12.5%, 28, -$1450, 0, 1) = $59.97

– Pmt([InterestRate], [LengthOfLoan [LoanAmount])

– Pmt([InterestRate]/12, [LengthOfLoan], [LoanAmount])

The Future Value of an Investment

To calculate the future value of an investment, use the FV() function.

The syntax of this function is:

FV(Rate, Periods, Payment, PresentValue, PaymentType)

PaymentType is optional

The Number of Periods of an InvestmentTo calculate the number of periods of an investment or a loan, use the NPer() function.

The syntax of this function is:

NPer(Rate, Payment, PresentValue, FutureValue, PaymentType);

Amount Paid As Interest During a Period The IPmt() function is used to calculate the amount paid as interest on a loan during aa period of the lifetime of a loan or an investment.

The syntax of this function is:

IPmt(Rate, Period, NPeriods, PresentValue, FutureValue, PaymentType)

The Amount Paid as Principal

The PPmt() function calculates the actual amount that applies to the balance of the loan.

The syntax of this function is:

PPMT(Rate, Period, NPeriods, PresentValue, FutureValue, PaymentType)

Present Value of Loan or Investment

The PV() function calculates the total amount that future investments are worth currently.

The syntax of this function is:

PV(Rate, NPeriods, Payment, FutureValue, PaymentType)

Understanding Period, Nper, and Rate

Math and Trig Functions• Abs(number)• Int(number)• Sgn(number)• Sqr(number)• Atn(number)• Log(number)• Sin(angle)• Cos(angle)• Tan(angle)

Informational Functions• IsNull

– Returns a Boolean value that indicates whether an expression contains no valid data (Null).

– Syntax• IsNull(expression)

• Nz– return a value when a variant is null.– The syntax for the Nz function is:

• Nz ( variant, [ value_if_null ] )• Nz (varName, "n/a") - would return the

value 'n/a' if the variable varName contained a null value.

Informational Functions• IsError

– Returns a Boolean value indicating whether an expression is an error value.

– Syntax• IsError(expression)

• Typename– Returns a String that provides

information about a variable.– Syntax

• TypeName(varname)

Informational Functions• IsNumeric

– Returns a Boolean value indicating whether an expression can be evaluated as a number.

– Syntax• IsNumeric(expression)

Strings Returned By Typename

The Replace FunctionThe Replace function replaces a sequence of characters in a string with another set of characters (a number of times).

The syntax for the Replace function is:

Replace ( string1, find, replacement, [start, [count, [compare]]] )

The start, count, and compare arguments are optional

The Replace FunctionExamples:

•Replace("alphabet", "bet", "hydro") would return "alphahydro"

•Replace ("alphabet", "a", "e") would return "elphebet“ •Replace("alphabet", "a", "e", 2)

would return "lphebet"

•Replace("alphabet", "a", "e", 1, 1) would return "elphabet"

The start, count, and compare arguments are optional

Functions You Should Know•Date √•DateValue•Day360•Minute•Now()•Second•Time•Year•DDB √•FV √•IRR •MIRR

•NPV•NPER•PMT √•PV•RATE•SLN•SYD•ABS √•ATAN √•COMBIN•COS•EXP

•COLUMN•HYPERLINK•AVG √•COUNT √•MAX √•MIN √•STDEVP•VARP•CHAR• CONCATENATE √•LEFT•LEN √

•LOWER•MID•REPLACE √•RIGHT•TRIM•UPPER•TRIM

•INT √•LOG √ •RAND √•SUM √•TAN √•ISNULL √•ISNA•ISNONTEXT•SINUMBER•NZ √•TYPE √•CHOOSE

√ = covered in this workshop