Unit 6 (Data Manipulation and Control II 1)

8/12/2019 Unit 6 (Data Manipulation and Control II 1)

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DATA MANIPULATION AND CONTROL - II

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Objectives

At the end of this unit, you will be able to

Lea!n to "!eate #iews, inde$es and se%uen"es

Topics

C!eation of #iews

Data Mani&ulation th!ou'h #iews

C!eation of Inde$es

C!eation of se%uen"es

(


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Views

O#e!#iew A #iew is a database ob)e"t that is a lo'i"al !e&!esentation of one

o! *o!e tables+

A #iew does not "ontain data+ Instead, a #iew is a #i!tual table,de!i#in' its data f!o* base tables+

ou "an thin of #iew as a sto!ed %ue!y+

The %ue!y &o!tion of the "!eate #iew state*ent, sele"ts "olu*ns

and !ows f!o* s&e"ified tables usin' the standa!d sele"t synta$ butORD.R / "lause is not allowed+

P!i#ile'es "an be '!anted on #iews+

Ad#anta'es

0e"u!ity Can li*it a""ess to s&e"ifi" table2s "olu*ns

usin' a #iew and "!eate #alue based se"u!ity definin' a

#iew fo! s&e"ifi" !ows+

Con#enien"e 3iews "an !e&!esent !esults of *any

diffe!ent tables+

Pe!s&e"ti#e- 3iews "an hide data "o*&le$ity and &!esent

data in anothe! way without affe"tin' basi" table definition

Li*itations

Use!s "annot inse!t, u&date o! delete !e"o!ds th!ou'h a #iew

based on a 4ROUP / o&tion o! a 5OIN, sin"e it is not

"lea! to the database se!#e! how to *a& a data *ani&ulation

o&e!ation ba" to the unde!lyin' base table6s7 of a #iew+

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Example 3iew e*&(9 "!eated f!o* .MP table+

Table .MP

.MPNO .NAM. 5O/ M4R :IR.DAT. 0AL COMM D.PTNO

;8 ;=9( 1;-D.C-=? @99 (9

;== A0:A 0AL.0MAN ;


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Create View

Statement Create View

Pu!&ose P!esent lo'i"al subsets o! "o*binations of data by "!eatin' #iewsof tables

0ynta$

Where

OR R.PLAC. Re"!eates the #iew if it al!eady e$ists+

BORC. C!eates the #iew !e'a!dless of whethe! the #iew2sbase tables e$ist o! the owne! of the #iew has

&!i#ile'es on the base tables+

NOBORC. C!eates the #iew only if the base tables e$ist and the

owne! of the s"he*a "ontainin' the #iew has&!i#ile'es on the*

s"he*a is the s"he*a to "ontain the #iew+ If youo*its"he*a, O!a"le "!eates the #iew in you! own

s"he*a

3iewna*e is the na*e of the #iew+Alias s&e"ifies the na*es fo! e$&!essions sele"ted

Eue!y is a sele"t "lause

ith C:.C> o&tion s&e"ifies that inse!ts and u&dates &e!fo!*ed th!ou'h

the #iew "annot !esult in !ows that do not dis&lay

th!o'h the #iew %ue!y

Const!aintna*e is the na*e assi'ned to the C:.C> OPTION

"onst!aint

Note: hen the #iew is "!eated usin' BORC., 0.L.CT, IN0.RT,

UPDAT. o! D.L.T. state*ents "an be issued a'ainst the #iewonly if the base table is in the sa*e s"he*a o! the owne! o! the

#iew has &!i#ile'es on the table+

?

CR.AT. FOR R.PLAC.G FBORC. H NOBORC.G 3I.

Fs"he*a+G#iewna*eF6aliasF,aliasG7G

A0 %ue!y

IT: C:.C> OPTION FCON0TRAINT "onst!aintna*eG


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Example C!eate #iew "ontainin' e*&loyee nu*be!, na*e, )ob, de&a!t*entnu*be! fo! e*&loyees in de&a!t*ent (9

SQL Command 0ELJ CR.AT. 3I. e*&(96ID,Na*e,Destination,De&a!t*ent7( A0 0.L.CT e*&no,ena*e,)ob,de&tno

8 BROM e*&

:.R. de&tnoK(9

es!lt 3iew "!eated+

Example To "onfi!* the "ontents of the #iew "!eated in the abo#e e$a*&le+

SQL Command 0ELJ 0.L.CT BROM e*&(9

es!lt ID NAM. D.0I4NATION D.PARTM.NT --------- ---------- -------------------- -------------------

;8 (9

;? (9

;=9( BORD ANAL0T (9

;8 (9 ;? (9 ;=9( BORD ANAL0T (9

19 !ows sele"ted+

Example U&datin' the #iew

SQL Command 0ELJ UPDAT. e*&(9

( 0.T de&a!t*entK89

8 :.R. idK1(8

es!lt 1 !ow u&dated+


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Example To "onfi!* the "han'es to the #iew *ade by the abo#e e$a*&le+

SQL Command 0ELJ 0.L.CT BROM e*&(9

es!lt ID NAM. D.0I4NATION D.PARTM.NT

--------- ---------- -------------------- --------------------

;8 (9 ;? (9

;=9( BORD ANAL0T (9 ;8 (9

;? (9 ;=9( BORD ANAL0T (9

19 !ows sele"ted+

To ensu!e that inse!ts and u&dates &e!fo!*ed th!ou'h #iew will not

affe"t data that the #iew owns, "!eate the #iew with the IT:

C:.C> OPTION "onst!aint+ The IT: C:.C> OPTION taes"a!e to see that the #alues to the "olu*n s&e"ified in this "lause is

not inse!ted o! u&dated, in su"h a way that, it no lon'e! fo!*s &a!t

on the #iew, i+e, it does not #iolate the #iew2s definition+

Example C!eate #iew "ontainin' all "olu*ns f!o* e*& table fo! de&a!t*ent(9 IT: C:.C> o&tion+

SQL Command 0ELJ CR.AT. 3I. e*&l(9

( A0 0.L.CT BROM e*&8 :.R. de&tnoK(9

IT: C:.C> OPTION

es!lt 3iew "!eated+

;


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Example To "onfi!* the "ontents of #iew e*&l(9+

SQL Command 0ELJ 0.L.CT BROM e*&l(9

es!lt

.MPNO .NAM. 5O/ M4R :IR.DAT. 0AL COMM D.PTNO--------- ---------- --------- --------- --------------- --------- --------- ---------

;8 ;=9( 1;-D.C-@9


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Example To "!eate a #iew !e'a!dless of whethe! the #iew2s base tables e$isto! the owne! of the #iew has &!i#ile'es on the base tables+

SQL Command 0ELJ CR.AT. BORC. 3I. #1( A0 0.L.CT $$,yy, f!o* $y

es!lt a!nin' 3iew "!eated with "o*&ilation e!!o!s+

Alter View

Statement "LTE V#EW

$!rpose To !e"o*&ile a #iew

S%ntax

Where

COMPIL. "auses O!a"le to !e"o*&ile the #iew+

Example Alte! the #iew e*&l(9+

SQL Command 0ELJ ALT.R 3I. e*&l(9

( Co*&ile

es!lt 3iew alte!ed+

=

ALT.R 3I. Fs"he*a+ G

#iewna*e


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Drop View

Statement &O$ V#EW

$!rpose Re*o#e a #iew f!o* the database

S%ntax

Where

#iewna*e is the na*e of the #iew+

Example Delete the #iew e*&l(9 f!o* the database+

SQL Command 0ELJ DROP 3I. e*&l(9

es!lt 3iew d!o&&ed+

19

DROP 3I. #iewna*e

COMPIL.


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Se'!ence

A se%uen"e is a database ob)e"t f!o* whi"h use!s *ay 'ene!ate

Uni%ue inte'e!s+ 0e%uen"es "an be used to auto*ati"ally 'ene!ateP!i*a!y ey #alues+

Create Sequence

Statement CE"TE SEQ(ENCE

$!rpose 4ene!ate &!i*a!y ey #alues+

S%ntax

Where

0e%uen"ena*e is na*e of the se%uen"e 'ene!ated+

INCR.M.NT / s&e"ifies the inte!#al between se%uen"enu*be!s+ Default inte!#al #alue is 1+ Positi#e

nu*be! as"ends the se%uen"e, ne'ati#e nu*be!

des"ends the se%uen"e+ This nu*be! "annot be 9+

0TART IT: s&e"ifies the fi!st se%uen"e nu*be! to be

4ene!ated+ Default sta!t #alue is 1+

11

CR.AT. 0.EU.NC. se%uen"e na*e

FINCR.M.NT by nG

F0TART IT: nG

FMA3ALU. n H NOMA3ALU.QG

FMIN3ALU. n H NOMIN3ALU.G

FCCL. n H NOCCL.QG

FCAC:. n H NOCAC:.QG


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MA3ALU. s&e"ifies the *a$i*u* #alue the se%uen"e

"an 'ene!ate

NOMA3ALU. s&e"ifies the *a$i*u* #alue of 19 fo! a

des"endin' se%uen"e+

MIN3ALU. s&e"ifies the *ini*u* #alue the se%uen"e

"an 'ene!ate

NOMIN3ALU. s&e"ifies a *ini*u* #alue of 1 fo!

as"endin' se%uen"e o! -19 fo!

des"endin' se%uen"e+

CCL. s&e"ifies that the se%uen"e "ontinues to 'ene!ate

#alues afte! !ea"hin' its *in+ o! *a$ #alue+

NOCCL. s&e"ifies that the #alues of the se%uen"e a!enot &!eallo"ated+

CAC:. s&e"ifies how *any #alues the se!#e! will

&!eallo"ate and ee& in a "o**on *e*o!y a!ea of

the se!#e!, by default se!#e! will "a"he (9 #alues+

NOCAC:. s&e"ifies that #alues of the se%uen"e a!e not

&!eallo"ated+

ORD.R 'ua!antees that se%uen"e nu*be!s a!e

'ene!ated in o!de! of !e%uest+

NOORD.R does not 'ua!antee se%uen"e nu*be!s a!e 'ene!atedin o!de! of !e%uest+

Example C!eate a si*&le se%uen"e fo! de&t table+ 0ta!t with 89 and

in"!e*ent by 19+

SQLCommand 0ELJCR.AT. 0.EU.NC. sde&tno

( INCR.M.NT / 198 0TART IT: ?

es!lt 0e%uen"e "!eated+

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Example C!eate a se%uen"e with sta!t #alue (?, in"!e*ent by 19, *a$i*u*

#alue ??, and the se%uen"e "ontinues to 'ene!ate e#en afte! it has

!ea"hed its *a$i*u* #alue+

SQLCommand 0ELJD.0CRI/. use!se%uen"es

es!lt

Name N!ll T%pe------ ------ ------

0.EU.NC.NAM. NOT NULL 3ARC:AR(6897

MIN3ALU. NUM/.R

MA3ALU. NUM/.R

INCR.M.NT/ NOT NULL NUM/.R CCL.BLA4 3ARC:AR(617

ORD.RBLA4 3ARC:AR(617

CAC:.0IS. NOT NULL NUM/.R

LA0TNUM/.R NOT NULL NUM/.R

Example To #iew the "ontents of the use!se%uen"es table to "onfi!*, that

the "!eated se%uen"e is a &a!t of the Data Di"tiona!y+

SQLCommand 0ELJ0.L.CT se%uen"ena*e,*in#alue,*a$#alue,

( lastnu*be!,in"!e*entby

8 BROM use!se%uen"es

es!lt

SEQ(ENCEN")E )#NV"L(E )"*V"L(E #NCE)ENT+, L"STN()+E

------------------------- ---------------- ------------------ ---------------------- ---------------------

CU0TID 1 1+999.(; 1 =9=ORDID 1 1+999.(; 1


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AlterSequence

Statement "LTE SEQ(ENCE

$!rpose To "han'e the se%uen"e in one of these ways

Chan'in' the in"!e*ent between futu!e se%uen"e #alues

0ettin' o! eli*inatin' the *ini*u* o! *a$i*u* #alue

Chan'in' the nu*be! of "a"hed se%uen"e nu*be!s

0&e"ifyin' whethe! o! not se%uen"e nu*be!s *ust be o!de!ed+

S%ntax

Example Alte! the e$istin' se%uen"e s1 with in"!e*ent by 19, *a$i*u*

3alue =9, *ini*u* #alue 19 and se%uen"e should "ontinue to'ene!ate e#en afte! it has !ea"hed its *a$i*u* #alue and ha#e a

"a"he #alue of ?+

SQLCommand 0ELJCR.AT. 0.EU.NC. s1

( INCR.M.NT / 19

8 MA3ALU. =9 MIN3ALU. 19

? CCL. < CAC:. ?

es!lt 0e%uen"e alte!ed+

1

ALT.R 0.EU.NC. se%uen"e na*e

FINCR.M.NT by nG

FMA3ALU. n H NOMA3ALU.QG

FMIN3ALU. n H NOMIN3ALU.G

FCCL. n H NOCCL.QG

FCAC:. n H NOCAC:.QG


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Drop Sequence

Statement &O$SEQ(ENCE

$!rpose Re*o#e a se%uen"e f!o* the database+

S%ntax

Where

0e%uen"ena*e is na*e of the se%uen"e+

Example D!o& the se%uen"e "!eated fo! de&t table+

SQLCommand 0ELJDROP 0.EU.NC. sde&tno

es!lt 0e%uen"e d!o&&ed+

1?

DROP 0.EU.NC. se%uen"ena*e


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#ndexes

Overview Inde$es a!e o&tional st!u"tu!es asso"iated with tables to s&eed

%ue!y e$e"ution and o! 'ua!antee uni%ueness+

A table "an ha#e any nu*be! of inde$es - i*&lied t!ade offis %ue!y

s&eed #s+u&date s&eed+

A *a$i*u* of 1< "olu*ns "an be in"luded in a sin'le inde$+

Data a""ess in o!a"le is of th!ee ty&es

/y OW#&-Di!e"t a""ess usin' !ow add!ess that indi"ates the

e$a"t lo"ation of the data+

Bull table s"an- 0e%uential sea!"h th!ou'h all of the !ows in the

table+ /y inde$- /ina!y sea!"h usin' so!ted t!ee st!u"tu!e of "olu*n

#alues+

C!eate inde$ on a "olu*n if

Colu*n is used f!e%uently in W-EE "lauses o! in a )oin

"ondition+

.#e!y #alue within the "olu*n is uni%ue+

Colu*n "ontains a wide !an'e of #alues+

Colu*n is s&a!sely &o&ulated, that is, it has a la!'e nu*be! of

null #alues+ Table is la!'e and *ost %ue!ies a!e e$&e"ted to !et!ie#e fewe!

than 19-1? of the !ows+

Note O!a"le se!#e! will "hoose a data a""ess *ethod based u&on the

e$istan"e of inde$es and the st!u"tu!e of the sele"t state*ent+

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CREATE INDEX

Statement CE"TE #N&E*

$!rpose C!eate si*&le inde$es to i*&!o#e %ue!y &e!fo!*an"es on f!e%uently

%ue!ied "olu*ns+ C!eate uni%ue inde$es to ensu!e that no two !ows will

"ontain identi"al #alues in the !efe!en"es "olu*n6s7+

S%ntax

Where Inde$na*e is na*e of the inde$

Tablena*e is na*e of the table

Colu*nna*e is na*e of the "olu*n

Example C!eate si*&le inde$ on "olu*n ena*e of table e*&+

SQL Command 0ELJ CR.AT. IND. Iena*e

( On e*&6ena*e7

es!lt Inde$ "!eated+

Example C!eate uni%ue inde$ on "olu*n e*&no of table e*&+

SQL Command 0ELJ CR.AT. UNIEU. IND. Ie*&noena*e

( ON e*&6e*&no,ena*e7

es!lt Inde$ C!eated+

Example . Confi!* the e$isten"e of inde$es f!o* the data di"tiona!y #iewU0.RIND..0

SQL Command 0ELJ D.0CRI/. U0.RIND..0

1;

CR.AT. IND. H UNIEU. IND. inde$na*e

ON tablena*e 6"olu*nna*e F,"olu*nna*eG+7


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es!lt Na*e Null Ty&e

----------------- -------- ---------IND.NAM. NOT NULL 3ARC:AR(6897

IND.TP. 3ARC:AR(6(;7

TA/L.ON.R NOT NULL 3ARC:AR(6897TA/L.NAM. NOT NULL 3ARC:AR(6897

TA/L.TP. 3ARC:AR(6117

UNIEU.N.00 3ARC:AR(6=7COMPR.00ION 3ARC:AR(6@7

PR.BIL.N4T: NUM/.R

TA/L.0PAC.NAM. 3ARC:AR(6897

INITRAN0 NUM/.RMATRAN0 NUM/.R

INITIAL.T.NT NUM/.R

N.T.T.NT NUM/.R

MIN.T.NT0 NUM/.RMA.T.NT0 NUM/.R

PCTINCR.A0. NUM/.RPCTT:R.0:OLD NUM/.R

INCLUD.COLUMN NUM/.R

BR..LI0T0 NUM/.RBR..LI0T4ROUP0 NUM/.R

PCTBR.. NUM/.R

LO44IN4 3ARC:AR(687

/L.3.L NUM/.RL.AB/LOC>0 NUM/.R

DI0TINCT>.0 NUM/.R

A34L.AB/LOC>0P.R>. NUM/.RA34DATA/LOC>0P.R>. NUM/.R

CLU0T.RIN4BACTOR NUM/.R

0TATU0 3ARC:AR(6@7NUMRO0 NUM/.R

0AMPL.0IS. NUM/.R

LA0TANALS.D DAT.

D.4R.. 3ARC:AR(697IN0TANC.0 3ARC:AR(697

PARTITION.D 3ARC:AR(687

T.MPORAR 3ARC:AR(6174.N.RAT.D 3ARC:AR(617

0.CONDAR 3ARC:AR(617

/UBB.RPOOL 3ARC:AR(6;7U0.R0TAT0 3ARC:AR(687

DURATION 3ARC:AR(61?7

PCTDIR.CTACC.00 NUM/.R

ITPON.R 3ARC:AR(6897ITPNAM. 3ARC:AR(6897

1@


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PARAM.T.R0 3ARC:AR(619997

4LO/AL0TAT0 3ARC:AR(687

DOMID0TATU0 3ARC:AR(61(7DOMIDOP0TATU0 3ARC:AR(6


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S%non%ms

O#e!#iew 0ynony*s "an be "!eated fo! !easons of se"u!ity and "on#enien"e+0ynony*s "an be eithe! &ubli" o! &!i#ate+

Publi" A synony*n "!eated by D/A,a""essible to all use!s

P!i#ate A synony* a""essible by the synony*2s "!eato!

only

Ad#anta'es

To !efe!en"e Tables 3iew without s&e"ifyin' the owne! o!

database Meanin'ful na*in' "on#entions

O!a"le will use a synony* when !esol#in' !efe!en"es to a

table#iew only when

The table#iew is &!efa"ed by a use! na*e and

The table#iew is not followed by a database lin

Example Assu*e that U0.R1 has 'i#en '!ant &e!*ission on .MP table to

U0.R(+ If U0.R( wants to %ue!y the .MP table the state*entwill be as follows

0.L.CT BROM U0.R1+.MP

Instead a synony* e*&l "an be "!eated fo! U0.R1+.MP+

0o, any fu!the! !efe!en"es to table U0.R1+.MP "an be done withe*&l+

Create Synonym

Statement CE"TE S,NON,)

$!rpose Alte!nate na*es fo! ob)e"ts, fo! "on#enien"e

S%ntax

(9

CR.AT. FPU/LICG 0NONM synony*na*e

BOR ob)e"tna*e


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Where

PU/LIC C!eates a synony* a""essible to all use!s+

Ob)e"tna*e identifies the ob)e"t fo! whi"h the synony*is "!eated+

Example C!eate a synony* de&a!t fo! de&t+

SQL Command 0ELJ CR.AT. 0NONM de&a!t

( BOR de&t

es!lt 0ynony* "!eated+

Drop Synonym

Statement &O$ S,NON,)

$!rpose D!o& synony* f!o* database

S%ntax

Where 0ynony*na*e is na*e of the synony*

Example D!o& the synony* "!eated

SQL Command 0ELJDROP 0NONM de&a!t

es!lt 0ynony* d!o&&ed+

(1

DROP 0NONM synony*na*e


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RENAME

Statement EN")E

$!rpose Chan'es na*es of ob)e"ts in the "u!!ent s"he*a+ The ob)e"ts

"an be tables, #iews,se%uen"es o! &!i#ate synony*s

S%ntax

WhereOldna*e is na*e of the ob)e"t whi"h has to be "han'ed

Newna*e is na*e to be assi'ned to the ob)e"t

Example Chan'e the na*e of the table e*& to newe*&

SQL/Command 0ELJ R.NAM. e*& TO newe*&

es!lt Table !ena*ed+

((

R.NAM. oldna*e TO newna*e


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S())", :0

A 3I. is a database ob)e"t that "ontains no data of its own

Any "han'es to the table asso"iated with a 3I., will auto*ati"ally !efle"t in the

3I.

Mani&ulatin' tables th!ou'h a 3I. ha#e "e!tain !est!i"tions

IT: C:.C> OPTION "lause alon' with CR.AT. 3I. "o**and allows

inte'!ity "onst!aints and data #alidation "he"s to be enfo!"ed on data bein'

IN0.RT.D o! UPDAT.D

5oin #iew "n also be *odified but any UPDAT, IN0.RT o! D.L.T. state*ent on a

)oin #iew "an *odify only one unde!lyin' base table

Pe!fo!*an"e "an be i*&!o#ed by inde$in' o! "luste!in' the tables

0e%uen"es a!e used to 'ene!ate uni%ue nu*be!s, in as"endin' o! des"endin' o!de!

The &seudo-"olu*n N.T3AL is used to e$t!a"t su""essi#e se%uen" nu*be!s f!o* a

s&e"ified se%uen"e CURR3AL is used to !efe! to a se%uen"e nu*be! that is the

"u!!ent se%uen"e nu*be!

0e%uen"es "an be alte!ed and d!o&&ed+

Unit 6 (Data Manipulation and Control II 1)

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Transcript of Unit 6 (Data Manipulation and Control II 1)