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2Copyright Oracle Corporation, 2001. All rights reserved.

Restricting and Sorting Data

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2-2 Copyright Oracle Corporation, 2001. All rights reserved.

Objectives

After completing this lesson, you should be able todo the following

!imit the rows retrieved by a "uery

Sort the rows retrieved by a "uery

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2-# Copyright Oracle Corporation, 2001. All rights reserved.

!imiting Rows $sing a Selection

%retrieve allemployees

in department &'(

EMPLOYEES

)

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2-* Copyright Oracle Corporation, 2001. All rights reserved.

!imiting the Rows Selected

Restrict the rows returned by using theWHEREclause+

heWHEREclause follows the FROMclause+

SELECT *|{[DISTINCT] column|expression[alias],...}

FROM table[WHERE condition(s)];

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2- Copyright Oracle Corporation, 2001. All rights reserved.

$sing theWHERE.lause

SELECT emploee!"#, l$%&!'$me, (o)!"#, #ep$&me'&!"#

FROM emploee%

WHERE #ep$&me'&!"# + - ;

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2-/ Copyright Oracle Corporation, 2001. All rights reserved.

.haracter Strings and Dates

.haracter strings and date values are enclosed insingle "uotation mar0s+

.haracter values are case sensitive, and date

values are format sensitive+ he default date format is DD-1O-RR+

SELECT l$%&!'$me, (o)!"#, #ep$&me'&!"#

FROM emploee%

WHERE l$%&!'$me + W/$le';

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.omparison .onditions

Operator

4

5

54

6

64

65

1eaning

7"ual to

8reater than

8reater than or e"ual to

!ess than

!ess than or e"ual to

ot e"ual to

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SELECT l$%&!'$me, %$l$

FROM emploee%

WHERE %$l$ 0+ 1---;

$sing .omparison .onditions

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Other .omparison .onditions

Operator

2ETWEEN

...3ND...

IN4%e&5

LI6E

IS N7LL

1eaning

:etween two values ;inclusive

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$sing the 2ETWEEN.ondition

$se the 2ETWEENcondition to display rows based on arange of values+

SELECT l$%&!'$me, %$l$

FROM emploee%

WHERE %$l$ 2ETWEEN 89-- 3ND 19--;

!ower limit $pper limit

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SELECT emploee!"#, l$%&!'$me, %$l$, m$'$:e!"#

FROM emploee%

WHERE m$'$:e!"# IN 4--, -, 8-5;

$sing the IN.ondition

$se the INmembership condition to test for values in

a list+

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$sing the LI6E.ondition

$se the LI6Econdition to perform wildcardsearches of valid search string values+

Search conditions can contain either literal

characters or numbers

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@ou can combine pattern-matching characters+

@ou can use the ESC3PEidentifier to search for theactual %and_ symbols+

$sing the LI6E.ondition

SELECT l$%&!'$me

FROM emploee%

WHERE l$%&!'$me LI6E !o

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$sing theN7LL.onditions

est for nulls with the IS N7LLoperator+

SELECT l$%&!'$me, m$'$:e!"#

FROM emploee%WHERE m$'$:e!"# IS N7LL;

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!ogical .onditions

Operator

3ND

OR

NOT

1eaning

Returns TR7Eif both component

conditions are true

Returns TR7Eif either componentcondition is true

Returns TR7Eif the following

condition is false

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$sing the3NDOperator

3NDre"uires both conditions to be true+

SELECT emploee!"#, l$%&!'$me, (o)!"#, %$l$

FROM emploee%

WHERE %$l$ >+----

3ND (o)!"# LI6E

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$sing the OROperator

ORre"uires either condition to be true+

SELECT emploee!"#, l$%&!'$me, (o)!"#, %$l$

FROM emploee%

WHERE %$l$ >+ ----

OR (o)!"# LI6E

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SELECT l$%&!'$me, (o)!"#

FROM emploee%

WHERE (o)!"#

NOT IN 4IT!PRO?, ST!CLER6, S3!REP5;

$sing theNOTOperator

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Rules of recedence

Override rules of precedence by using parentheses+

Order 7valuated Operator

> Arithmetic operators

2 .oncatenation operator

# .omparison conditions* IS[NOT]N7LL, LI6E, [NOT]IN

[NOT] 2ETWEEN

/ NOTlogical condition

3 3NDlogical condition9 ORlogical condition

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SELECT l$%&!'$me, (o)!"#, %$l$

FROM emploee%

WHERE (o)!"# + S3!REP

OR (o)!"# + 3D!PRES

3ND %$l$ > 9---;

Rules of recedence

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SELECT l$%&!'$me, (o)!"#, %$l$

FROM emploee%

WHERE 4(o)!"# + S3!REP

OR (o)!"# + 3D!PRES5

3ND %$l$ > 9---;

Rules of recedence

$se parentheses to force priority+

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SELECT l$%&!'$me, (o)!"#, #ep$&me'&!"#, /"e!#$&e

FROM emploee%ORDER 2Y /"e!#$&e ;

ORDER 2Y.lause

Sort rows with the ORDER 2Yclause AS. ascending order, default

D7S. descending order

he ORDER 2Yclause comes last in the SELECT

statement+

)

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2-2# Copyright Oracle Corporation, 2001. All rights reserved.

Sorting in Descending Order

SELECT l$%&!'$me, (o)!"#, #ep$&me'&!"#, /"e!#$&e

FROM emploee%

ORDER 2Y /"e!#$&e DESC ;

)

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he order of ORDER 2Ylist is the order of sort+

@ou can sort by a column that is not in theSELECTlist+

SELECT l$%&!'$me, #ep$&me'&!"#, %$l$

FROM emploee%

ORDER 2Y #ep$&me'&!"#, %$l$ DESC;

Sorting by 1ultiple .olumns

)

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2-2/ Copyright Oracle Corporation, 2001. All rights reserved.

Summary

SELECT *|{[DISTINCT] column|expression[alias],...}

FROM table[WHERE condition(s)]

[ORDER 2Y {column, expr, alias} [3SC|DESC]];

=n this lesson, you should have learned how to

$se theWHEREclause to restrict rows of output $se the comparison conditions

$se the 2ETWEEN, IN, LI6E, andN7LLconditions

Apply the logical3ND, OR, andNOToperators

$se the ORDER 2Yclause to sort rows of output

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ractice 2 Overview

his practice covers the following topics

Selecting data and changing the order ofrows displayed

Restricting rows by using theWHEREclause Sorting rows by using the ORDER 2Yclause

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les02.ppt

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