sql lecture-4

8/10/2019 SQL Lecture-4

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RDBMS Using OracleRDBMS Using Oracle

Lecture week 4Lecture week 4

Lecture OverviewLecture Overview

LPAD, RPADLPAD, RPAD

LTRIM, RTRIM, TRIMLTRIM, RTRIM, TRIM

SUBSTRSUBSTR

REPLACEREPLACE TRNSLATETRNSLATE

SOUNDAXSOUNDAX

SINGLE ROWSINGLE ROW

NUMARIC FUNCTIONSNUMARIC FUNCTIONS

ROUND, CEILROUND, CEIL

FLOOR, ABSFLOOR, ABS

SIN, SINHSIN, SINH

COS, COSHCOS, COSH

TAN, TANHTAN, TANH

EXP. LN, LOG & othersEXP. LN, LOG & others


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LPADLPAD andand RPADRPAD

LPAD and RPAD both are used to pad(stuffing)LPAD and RPAD both are used to pad(stuffing)characters.characters.

LAPDLAPD is used to pad extra characters at theis used to pad extra characters at the

beginning (left side) of column values.beginning (left side) of column values.

SimilarlySimilarly RAPDRAPD is used to pad extra charactersis used to pad extra charactersat the right side (end) of column values.at the right side (end) of column values.

LPAD and RPAD take three arguments.LPAD and RPAD take three arguments.LPAD (, [,])LPAD (, [,]) RPAD (, [,])RPAD (, [,])

The first is the character string (column) to beThe first is the character string (column) to beoperated on.operated on.

The second argument is the number ofThe second argument is the number ofcharacters to pad with it.characters to pad with it.

and the optional third argument is the characterand the optional third argument is the characterto pad it with (default is Single Space).to pad it with (default is Single Space).


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SQL> select ename, LPAD(ename ,10 , * )

from emp;

ENAME LPAD(ENAME)

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

SMITH *****SMITH

ALLEN *****ALLEN

WARD ******WARD

JONES *****JONES

MARTIN ****MARTIN

BLAKE *****BLAKE

SQL> select ename, RPAD(ename ,10 , * )

from emp;

ENAME LPAD(ENAME)

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

SMITH SMITH *****ALLEN ALLEN *****

WARD WARD ******

JONES JONES *****

MARTIN MARTIN ****


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LTRIM and RTRIMLTRIM and RTRIM

LTRIM and RTRIMLTRIM and RTRIM are used to REMOVE anyare used to REMOVE any

characters from the values of any specified column.characters from the values of any specified column.

LTRIM and RTRIM takesLTRIM and RTRIM takes twotwo argumentsarguments

The first is the character string (column) to beThe first is the character string (column) to be

operated on.operated on.

and the optional 2nd argument are the charactersand the optional 2nd argument are the characters

that are to be eliminated. (default is Single Space).that are to be eliminated. (default is Single Space).

SQL> select job , LTRIM ( JOB , S ) from emp;

JOB LTRIM(JOB)

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

CLERK CLERK

SALESMAN ALESMANSALESMAN ALESMAN

MANAGER MANAGER

SALESMAN ALESMAN

MANAGER MANAGER

S is removed from the beginning of JOB column

LTRIM


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SQL> select job , RTRIM ( JOB , MAN ) from emp;

JOB RTRIM(JOB)

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

CLERK CLERK

SALESMAN SALES

SALESMAN SALES

MANAGER MANAGER

SALESMAN SALES

MANAGER MANAGER

MAN is removed from the right side of JOB column

RTRIM

Removing more then one characterRemoving more then one character

SQL> select JOB, LTRIM(JOB, 'CS') from emp;

JOB LTRIM(JOB

--------- ---------CLERK LERK

SALESMAN ALESMAN

SALESMAN ALESMAN

MANAGER MANAGER

SALESMAN ALESMAN

MANAGER MANAGER


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Used of LPAD and LTRIMUsed of LPAD and LTRIMSQL> select JOB, LPAD ( LTRIM (JOB, CS ) , 10 , '*')

from emp;

JOB LPAD(LTRIM

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

CLERK ******LERK

SALESMAN ***ALESMAN

SALESMAN ***ALESMAN

MANAGER ***MANAGER

SALESMAN ***ALESMAN

MANAGER ***MANAGER

LPAD ( LTRIM (JOB, CS ) , 10 , '*')

This is

working

like this

TRIMTRIM TRIM ([[] from] ) can take threeTRIM ([[] from] ) can take three

arguments where C2 and C3 are character strings.arguments where C2 and C3 are character strings.

If present, C1 can be following literals:If present, C1 can be following literals:

LEADING, TRAILING OR BOTH. This function returnsLEADING, TRAILING OR BOTH. This function returns

C3 with all (leading, trailing or both) occurrence ofC3 with all (leading, trailing or both) occurrence ofcharacters in C2 removed.characters in C2 removed.

A NULL is returned if any one of C1, C2 or C3 is NULL.A NULL is returned if any one of C1, C2 or C3 is NULL.

C1 is default to BOTH, C2 defaults to a space characterC1 is default to BOTH, C2 defaults to a space character


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SQL> select trim(' FULLY PADED ') test1,SQL> select trim(' FULLY PADED ') test1,trim(' LEFT PADED') test2,trim(' LEFT PADED') test2,

trim ('Righttrim ('Right PadedPaded ')test3 from dual;')test3 from dual;

TEST1TEST1 TEST2TEST2 TEST3TEST3

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

FULLY PADEDFULLY PADED LEFT PADEDLEFT PADED RightRight PadedPaded

ReplaceReplace

REPLACE Takes Three ArgumentsREPLACE Takes Three Arguments

REPLACE (, [,])REPLACE (, [,])

Where C1, C2 and C3 are character StringsWhere C1, C2 and C3 are character Strings

This function returns C1 with all occurrences of C2 replaceThis function returns C1 with all occurrences of C2 replacewith C3.with C3.

C3 Defaults to NULL, all occurrences of C2 are removedC3 Defaults to NULL, all occurrences of C2 are removed

If C2 is NULL then C1 returns unchangedIf C2 is NULL then C1 returns unchanged


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This function is useful for dynamic substitutionsThis function is useful for dynamic substitutions

ExampleExample

Select REPLACE (UPTOWN, UP,Select REPLACE (UPTOWN, UP,

DOWN) from dual;DOWN) from dual;

Output DOWNTOWNOutput DOWNTOWN

Practice (Replace)Practice (Replace)

Apply REPLACE on JOB column of EMP tableApply REPLACE on JOB column of EMP table

and Replace SALES to NULL for JOBand Replace SALES to NULL for JOB

SALESMAN.SALESMAN.

SQL> select replace(ename, 'AL', '?=') from emp

REPLACE(ENAME,'AL','

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

SMITH

?=LEN

WARD

OutputOutputJOBJOB

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

MANMAN

MANMAN


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SOUNDEXSOUNDEX

SOUNDEX () takes a single argument ofSOUNDEX () takes a single argument ofCharacter String.Character String.

This function returns theThis function returns the SoundexSoundex PhotonicPhotonic

representation if C1.representation if C1.

The SOUNDEX function is usually used to findThe SOUNDEX function is usually used to find

name that sound alike.name that sound alike.

SQL> select soundex(ename) from emp;

SOUN

----

S530

A450

W630

J520M635

B420

SQL> select soundex('DAWES') from dual;

SOUN

----

D200

SQL> select soundex('DAYS')from dual;

SOUN

----

D200

SQL> select soundex('DAWS') from dual;

SOUN

----

D200

Try for some other

similar word

???????????????????


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TRANSLATETRANSLATE TRANSLATE (,,) takes three character stringTRANSLATE (,,) takes three character string

arguments.arguments.

The function returns C1 with all occurrences of characters in C2The function returns C1 with all occurrences of characters in C2replaced with thereplaced with the positionallypositionallycorresponding characters in C3.corresponding characters in C3.

A NULL is returned if any one of C1, C2 or C3 is NULL.A NULL is returned if any one of C1, C2 or C3 is NULL.

If C3 has fewer characters then C2, then unmatched character inIf C3 has fewer characters then C2, then unmatched character in C2 areC2 areremoved from C1.removed from C1.

If C2 has fewer characters then C3, then unmatched character froIf C2 has fewer characters then C3, then unmatched character from C3m C3are ignored.are ignored.

select translate('ABCDEF', 'FEDCBA', '123456') from dual

TRANSL

------

654321

SQL>select ename, translate(ename, 'ABCDEF', '123456') from emp

ENAME TRANSLATE(---------- ----------

SMITH SMITH

ALLEN 1LL5N

WARD W1R4

JONES JON5S

MARTIN M1RTIN

BLAKE 2L1K5

CLARK 3L1RK

NOTE:-

Practice and Analyze the difference

in REPLACE AND TRANSLATE

Function by applying

both functions on same data


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Single ROW NumericSingle ROW NumericFunctionsFunctions

Numeric Functions operate on numeric dataNumeric Functions operate on numeric dataand perform some kind of mathematical orand perform some kind of mathematical or

arithmetic manipulationarithmetic manipulation

Single ROW NumericSingle ROW Numeric

FunctionsFunctions

There is a huge list of Single ROW Numeric Functions,There is a huge list of Single ROW Numeric Functions,few of them are listed below.few of them are listed below.

ROUNDROUND

CEILCEIL FLOORFLOOR

ABSABS

SIN, SINHSIN, SINH

COS, COSHCOS, COSH

TAN, TANHTAN, TANH

EXP. LN, LOG & othersEXP. LN, LOG & others


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ROUND FunctionROUND Function

The round function rounds a number to a

Specified number of decimal places.

Example (Next slide)


Suppose we have written following SQLSuppose we have written following SQL

statementstatement

SQL> select ename, sal/22 from emp;

ENAME SAL/22

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

SMITH 36.3636364

ALLEN 72.7272727

WARD 56.8181818

JONES 20.2840909

MARTIN 56.8181818

BLAKE 19.4318182


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Use ofUse of ROUND FunctionSQL> select ename, sal/22 , ROUND (sal/22)

from emp;

ENAME SAL/22 ROUND(SAL/22)

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

SMITH 36.3636364 36

ALLEN 72.7272727 73

WARD 56.8181818 57

JONES 20.2840909 20MARTIN 56.8181818 57

BLAKE 19.4318182 19

Use ofUse of ROUND Function to round result to

one, two, three or more decimal places

SQL>select ename, sal/22 , ROUND (sal/22 , 1) ,

ROUND (sal/22 , 2) from emp;

ENAME SAL/22 ROUND(SAL/22 , 1) ROUND(SAL/22 , 2)

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

SMITH 36.3636364 36.4 36.36

ALLEN 72.7272727 72.7 72.73

WARD 56.8181818 56.8 56.82

JONES 20.2840909 20.3 20.28

MARTIN 56.8181818 56.8 56.82


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ABS (Absolute)ABS (Absolute)

FunctionFunction

The ABS function returns theThe ABS function returns the

positive value of the number.positive value of the number.

For exampleFor example

In the following SQL statementIn the following SQL statement COMMCOMMSALSAL

will returnwill return vevevalues (where the value ofvalues (where the value of

COMM is less then the SAL value)COMM is less then the SAL value)

SQL> select ename, comm, sal, comm sal

from emp where comm is not null

ENAME COMM SAL COMM-SAL

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

ALLEN 300 1600 -1300

WARD 500 1250 -750

MARTIN 1400 1250 150

TURNER 0 1500 -1500

GEO 800 1500 -700


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The ABS functionThe ABS functionABS (COMM SAL)

returns the positive value of the numberreturns the positive value of the number..

SQL> select ename, comm, sal, ABS(comm sal)

from emp where comm is not null

ENAME COMM SAL ABS(COMM-SAL)

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

ALLEN 300 1600 1300

WARD 500 1250 750

MARTIN 1400 1250 150TURNER 0 1500 1500

GEO 800 1500 700

CEILCEIL && FLOORFLOOR

FunctionFunctionCEIL & FLOOR both are used to convert numbers

with decimals places into integers.

CEIL is used to get higher integer value

e.g 2.34 or 2.7 or 2.1 or 2.8 (will be converted into) 3

FLOORis used to get lower integer value

e.g 2.34 or 2.7 or 2.1 or 2.8 (will be converted into) 2


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USE ofUSE ofSIN, SINH, COS, COSH,SIN, SINH, COS, COSH,

TAN, TANHTAN, TANH

FunctionsFunctions

USE ofUSE of SIN, SINH, COS,SIN, SINH, COS,

COSH,TAN, TANHCOSH,TAN, TANH

VariousVarious trignometictrignometic computations can be carried out bycomputations can be carried out by

usingusing SIN, SINH, COS, COSH, TAN and TANH.SIN, SINH, COS, COSH, TAN and TANH.

For exampleFor example

SQL> selectSQL> select salsal , sin (, sin (salsal) from) from empemp;; oror

Select sin (Select sin (salsal) ,) , coscos ((salsal) from) from empemp;; oror

SQL> selectSQL> select coscos (45) from dual;(45) from dual;

etc.. etcetc.. etc


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Use ofUse of

EXPEXP(mathematical function)(mathematical function)

&&

LN & LOGLN & LOG(Logarithm Function)(Logarithm Function)

LNLN function is used to find Natural logfunction is used to find Natural log

SQL> select sal, LN(sal) from emp;

SAL LN(SAL)

---------- ----------800 6.68461173

1600 7.37775891

1250 7.13089883

446.25 6.10087933

1250 7.13089883

SQL> select LN(45) from dual;

LN(45)----------

3.80666249

SQL> select EXP(24) from dual;

EXP(24)

----------

2.6489E+10


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List and Description of All Numeric Functions

List and Description of All Numeric Functions contd


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List and Description of All Numeric Functions contd

ThanksThanks

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