built-in functions - aggregate functions - sqlserverpedia

7/30/2019 Built-In Functions - Aggregate Functions - SQLServerPedia

1/49

9/03/13 Built-in F unctions - Aggregate F unctions - SQLServe rPedia

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Built-

in

Func

-

Aggr

Func

See

Also:

Main_

-

TransaSQL

Coding

Techni

-

Reusa

Coding

Techni

-

Functio

-

SQL

Server

2005

Built-

Ins

Aggreg

functio

return

a

single

value

summ

a

given

data

set.

All

aggreg

functio

are

determ

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2/49



NOTE:

AVG,

SUM,

STDEV

STDEV

VAR

and

VARP

functio

cannot

operat

on

BIT

data

types;

they

canoperat

on

all

other

numeri

data

types.

Con

[hide]

1

2

3

4

5

6

7

8

9

1

1

1

1

1

COUFun


3/49



The

COUN

functio

returns

a

count

of

rows

based

on

certain

criteria.

The

syntax

is :

Keywor

ALL

is

optiona

and

is

assum

by

default.

If

you

specify

a

"*"

asthe

criterio

COUN

returns

the

total

numbe

of

rows

in

a

table;

for

1.


4/49



exampl

the

followi

query

counts

rows

in

the

FactFin

table

of

Advent

Works

DW

databa

If

you

join

multipl

tables

then

COUN

returns

the

numbe

of

rows

satisfyi

the

join

criterio

as

in

the

followi

1.

2.

3.

4.

5.

6.


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6/49



ignore

NULL

values.

If

you

need

to

find

the

count

of

unique

items

within

a

column

in

a

table

use

COUN

(DISTI

column

syntax.

For

examplthe

followi

query

counts

unique

organi

keys

within

the

FactFin

table:

1.

2.

3.

4.

5.


7/49



COUFun

The

COUN

functio

is

identic

to

the

COUN

functio

but

returns

aBIGINT

data

type,

wherea

COUN

returns

an

INT.

The

upper

limit

for

INT

data

type

is

2

billion;

therefo

if

you

anticip

countin

more

than

two

billion

rows

use

the

COUN

6.


8/49



functio

Any

attemp

to

use

the

COUN

functio

when

countin

over

2

billion

rows

returns

an

error.

MAXFun

The

MAX

functio

returns

the

bigges

value

within

a

given

set.

The

syntax

is :

The

ALL

keywor

is

optiona

and

is

the

default

1.


9/49



unless

DISTIN

is

specifi

The

DISTIN

keywor

specifi

that

each

unique

value

should

be

consid

This

keyworreally

has

no

use

with

MAX

functio

since

it

returns

a

single

value;

howev

the

keywor

is

suppor

for

ANSI

compa

For

exampl

the

followi

returnsthe

greate

amoun

from


10/49



the

FactFin

table:

Note

that

the

param

of

MAX

can

be

any

valid

expres

includi

string

column

as

in

the

followi

"Wome

Tights,

S"

is

1.

2.

3.

4.

5.

6.

1.

2.

3.


11/49



returne

becaus

it is

the

last

value

in

the

alphab

ordere

list

of

produc

names

not

becaus

it isthe

longes

produc

name.

You

can

combin

MAX

functio

with

LEN

functio

to

return

the

produc

with

the

longes

names

as

follows

01.

02.

03.

04.

05.

06.


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07.

08.

09.

10.

11.


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MINFun

The

MIN

functio

returns

the

smalle

value

within

a

given

set.

The

syntax

is :

The

ALL

keywor

is

optionaand

is

the

default

unless

DISTIN

is

specifi

The

DISTIN

keywor

specifi

that

each

unique

value

should

be

consid

This

keywor

really

1.


14/49



has

no

use

with

MIN

functio

since

it

returns

a

single

value;

howev

the

keywor

is

supporfor

ANSI

compa

For

exampl

the

followi

returnsthe

least

amoun

from

the

FactFin

table:

1.

2.

3.

4.

5.


15/49



Note

that

the

param

of

MIN

can

be

any

valid

expres

includistring

column

as

in

the

followi

6.

1.

2.

3.

4.

5.

6.


16/49



Note

that

"Adjust

Race"

is

returne

becaus

it is

the

first

value

in

thealphab

ordere

list

of

produc

names

not

becaus

it is

the

shorte

produc

name.

You

can

combin

MIN

functio

with

LEN

functio

to

7.


17/49



return

the

produc

with

the

shorte

names

as

follows

01.

02.

03.

04.

05.

06.

07.

08.

09.

10.


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AVGFun

The

AVG

functio

returns

the

averag

of

the

values

withina

column

Unlike

MIN

and

MAX,

AVG

can

only

accept

a

numeri

expres

as

a

param

The

syntax

is :

ALL

keywor

is

optiona

and

is

assum

11.

1.


19/49



by

default.

You

can

specify

the

DISTIN

keywor

if

you

want

to

take

into

accoun

only

theunique

occurre

of

each

value.

The

followi

query

returnsthe

averag

amoun

from

FactFin

table:

The

next

exampl

1.

2.

3.

4.

5.

6.

7.


20/49



uses

DISTIN

keywor

to

return

the

averag

of

distinct

values:

The

AVG

functio

returns

the

same

(or

a

similar

data

type

as

the

group

of

values

it

accept

So

if

youpass

an

integer

expect

1.

2.

3.

4.

5.

6.

7.


21/49



an

integer

back;

if

you

examin

float

values

with

the

AVG

functio

you

will

get

a

floatvalue

back.

SUMFun

The

SUMfunctio

returns

the

sum

of

all

or

unique

values.

Unlike

MIN

and

MAX,

SUM

can

only

accept

a

numeri

expres

as

a


22/49



param

The

syntax

is :

ALL

keywor

is

optiona

and

is

assum

by

default.

You

can

specify

the

DISTIN

keywor

if

you

want

to

take

into

accoun

only

the

unique

occurreof

each

value.

The

followi

query

returns

the

sum

of

amoun

1.


23/49



from

FactFin

table:

The

next

exampl

uses

DISTIN

keywor

to

return

the

sumof

distinct

values:

The

SUM

functio

returns

the

1.

2.

3.

4.

5.

6.

7.

1.

2.

3.

4.

5.

6.

7.


24/49



same

(or

a

similar

data

type

as

the

group

of

values

it

accept

So

if

you

passan

integer

expect

an

integer

back;

if

you

examin

float

values

with

the

SUM

functio

you

will

get

a

float

value

back.

STDFun

The

STDEV

functio

calcula

the

standa


25/49



deviati

for

all

items

in

the

SELEC

statem

This

functio

can

only

be

used

with

numeri

columnThe

syntax

is :

ALL

keywor

is

optiona

and

is

assum

by

default.

Youcan

specify

the

DISTIN

keywor

if

you

want

to

take

into

accoun

only

1.


26/49



the

unique

occurre

of

each

value.

The

STDEV

functio

always

returns

a

FLOAT

data

type

value.

The

followi

exampl

returns

the

standa

deviati

of

amoun

from

FactFin

table:

1.

2.

3.

4.

5.

6.

7.


27/49



STDFun

The

STDEV

functiocalcula

the

standa

deviati

for

the

popula

of

items

in

the

SELEC

statem

This

functio

can

only

be

used

with

numeri

column

The

syntax

is :

ALL

keywor

is

optiona

and

is

assum

by

default.

You

1.


28/49



can

specify

the

DISTIN

keywor

if

you

want

to

take

into

accoun

only

the

unique

occurre

ofeach

value.

The

STDEV

functio

always

returns

a

FLOAT

data

type

value.

The

followi

exampl

returns

the

standa

deviati

of

popula

for

amoun

in

the

FactFintable:

1.

2.

3.


29/49



VARFun

The

VAR

functio

calcula

the

statisti

varianc

of

all

values

in

the

SELEC

statem

This

functio

can

only

be

used

with

numeri

column

The

syntax

is :

4.

5.

6.

7.

1.


30/49



ALL

keywor

is

optiona

and

is

assum

by

default.

You

can

specify

the

DISTINkeywor

if

you

want

to

take

into

accoun

only

the

unique

occurre

of

each

value.

The

VAR

functio

always

returns

a

FLOAT

data

type

value.

Thefollowi

exampl

returns

the


31/49



varianc

of

amoun

from

FactFin

table:

VARFun

The

VARP

functio

calcula

the

statisti

variancfor

the

popula

of

values

in

the

SELEC

statem

This

functio

can

only

1.

2.

3.

4.

5.


32/49



be

used

with

numeri

column

The

syntax

is :

ALL

keywor

is

optiona

and

is

assum

by

default.

You

can

specify

the

DISTIN

keywor

if

you

want

to

take

into

accounonly

the

unique

occurre

of

each

value.

The

VARP

functio

always

returns

a

1.


33/49



FLOAT

data

type

value.

The

followi

exampl

returns

the

varianc

for

the

popula

of

amounfrom

the

FactFin

table:

CHEFun

The

CHEC

functio

can

be

1.

2.

3.

4.

5.


34/49



used

to

detect

data

change

in

a

table.

This

functio

can

only

work

on

integer

data

type;otherwi

the

functio

is

very

similar

to

other

aggreg

functio

like

SUM

or

AVG.

The

syntax

is :

ALL

keywor

is

optiona

and

is

assum

by

default.

1.


35/49



You

can

specify

the

DISTIN

keywor

if

you

want

to

take

into

accoun

only

the

unique

occurreof

each

value.

The

CHEC

functio

always

returns

a

INT

data

type

value.

The

followi

query

returns

the

checks

of

amoun

column

in

FactFin

table;

thenit

update

some

rows


36/49



in

the

table;

the

second

checks

is

differen

from

the

first

indicati

that

the

data

values

havechange

Result

1.

2.

3.

1.

2.

3.


37/49



CHEFun

The

CHEC

functio

returns

the

checks

value

compu

over

a

row

in

a

given

table;

alterna

it

can

return

the

checks

of

the

specifi

list

of

values.

This

functio

isintende

for

buildin

hash

4.

5.

6.

7.


38/49



indexe

and

always

returns

an

INT

data

type

value.

The

syntax

is :

The

CHEC

flavor

examin

all

column

of

a

given

table;

it

returns

an

error

if

the

table

contain

TEXT,

NTEXT

or

IMAGE

data

type

column

Ifyou

specify

expres

instead

1.


39/49


40/49



The

next

exampl

returns

a

CHEC

of

given

values:

To

add

a

hash

index

to

a

table

you

need

to

add

a

compu

column

using

CHEC

5.

1.

2.

3.

4.

5.


41/49



functio

and

then

create

an

index

on

the

compu

column

as

in

the

followi

GR

FunThe

GROU

functio

returns

a

value

of

1 if

the

row

is

added

to

the

result

set

by

eitherROLLU

or

CUBE

clause

1.

2.

3.


42/49



of

the

SELEC

statem

CUBE

and

ROLLU

extensi

allow

genera

very

simple

textual

reports

in

a

querywindo

Majorit

of

busine

reports

will

use

more

sophis

reporti

tools

than

the

Query

Analyze

or

SQL

Server

Manag

Studio,

therefo

CUBE

and

ROLLU

extensi

as

well

asthe

GROU

functio

have


43/49



limited

usage.

The

syntax

of

the

GROU

functio

is :

The

column

is

a

column

referre

to

in

the

GROU

BY

statem

The

followi

query

returns

sum

of

amoun

per

organiand

total

of

all

organi

amoun

combin

as

a

separa

"groupi

row":

1.

01.


44/49



02.

03.04.

05.


45/49



06.

07.

08.

09.

10.

11.

12.

13.

14.

15.


46/49



The

ROLLU

extensi

and

the

GROU

functio

are

more

useful

when

the

report

is

groupi

recordbased

on

multipl

column

For

exampl

the

followi

query

groups

the

output

by

produc

class,

style

and

Englis

name:

1.


47/49



Note

that

a

groupi

row

is

genera

for

each

class,

each

class

and

style

combin

and

the

grand

total

of

all

sales.

MorSQL

ServFun

S

S

2

S

F

-

li

L

R

C

S


48/49



S

S

2

C

F

-

li

C

S

S

2

D

&

Ti

F

-li

D

D

G

S

S

2

M

F

-

li

R

C

F

S

S

2

T

a

I

F

-

li

P

T

S

S

2

S

F

-

built-in functions - aggregate functions - sqlserverpedia

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