--returnsan

column

internaloracleformat,used

forgettinginfoabouta

--formatoptions:8=oc

tal,10=decimel,16=hex,17=characters

--returntype

codes:1=varchar2,2=n

umber,8=long,12=date,

--23=raw,

24=longraw,69=rowid,

96=char,106=mlbel

greatest(expr[,expr2[,expr3...]]

--returnsthrgestval

ueofallexpressions

least(expr[,expr2[,expr3...]]

--returnsthe

smallestvalueofallexpre

ssions

nvl(expr1,expr2

--ifexpr1isnotnull,i

tisreturned,otherwiseexpr2isreturned

sqlcode

--returnssqlerrorcode

query,

osterror.cannotbeuseddirectlyin

--valuemust

besettolocalvariablefir

st

sqlerrm

--returnssql

inquery,

errormessageosterror

.cannotbeuseddirectly

--valuemustbesettolo

calvariablefirst

uid

--returnstheuseridof

theuseryouareloggedonas

--usefulins

electinginformationfromlo

wlevelsystables

user

--returnsthe

usernameoftheuseryoua

reloggedonas

userenv(‘option‘)

--returnsinf

ormationabouttheuseryou

areloggedonas

--options:e

ntryid,sessionid,terminal,

nguagebel,osdba

--(

alloptionsnotavablein

alloracleversions)

vsize(expr)

--returnsthenumberofb

ytesusedbytheexpression

--usefulins

electinginformationaboutt

ablespacerequirements

*

*sqldatefunctions(dtreprese

*

ntsoracledateandtime)

*(functionsreturn

*

anoracledateunlessotherw

isespecified)

*

add_months(dt,num)

--addsnummonthsto

dt(numcanbenegative)

st_day(dt)

-stdayofmonthin

monthcontainingdt