| General Information |
| Note:These are functions not covered on other site pages |
|
| LNNVL |
Evaluates a condition when one or both operands of the condition may be null |
LNNVL(<condition>) |
conn hr/hr
SELECTCOUNT(*)FROMemployeesWHEREcommission_pct >= .2;
SELECTCOUNT(*)FROMemployeesWHERELNNVL(commission_pct >= .2); |
|
| NULLIF |
| Compares expr1 and expr2. If they are equal,then the function returns null. If they are not equal,then the function returns expr1. You cannot specify the literal NULL for expr1. |
NULLIF(<expression1>,<expression2>) |
conn hr/hr
SELECTe.last_name,NULLIF(e.job_id,j.job_id) "OLD JOB ID"
FROMemployees e,job_history j
WHEREe.employee_id = j.employee_id
ORDER BYlast_name; |
|
| NVL |
Returns a Value if the Expression IS NULL |
NVL(
s1VARCHAR2CHARACTER SET ANY_CS,-- expression
s2VARCHAR2CHARACTER SET s1%CHARSET) -- return value if null
RETURNVARCHAR2CHARACTER SET s1%CHARSET;
NVL(B1 BOOLEAN,B2 BOOLEAN) return BOOLEAN; |
set serveroutput on
DECLARE
iPLS_INTEGER;
BEGIN
SELECTNVL(i,93)
INTOi
FROMDUAL;
dbms_output.put_line('i1: ' || i);
SELECTNVL(i,39)
INTOi
FROMDUAL;
dbms_output.put_line('i2: ' || i);
END;
/ |
|
| NVL2 |
Returns First Value if NOT NULL,Second Value if NULL
Thanks Cary Hogan and Kaifer Bohus for the corrections |
NVL2(<expression>,<return_if_not_null>,<return_if_null>) |
CREATETABLEtest (
categoryVARCHAR2(20),
outvalNUMBER(3),
invalNUMBER(3));
INSERTINTOtestVALUES('Groceries',10,NULL);
INSERTINTOtestVALUES('Payroll',NULL,100);
INSERTINTOtestVALUES('Groceries',20,200);
INSERTINTOtestVALUES('Groceries',30,NULL);
SELECT*FROMtest;
SELECTcategory,SUM(NVL2(outval,-outval,inval)) NET
FROMtest
GROUP BYcategory;
Note: If used in PL/sql must be used in the form ofSELECTINTO
thus you can not use this Syntax:
set serveroutput on
DECLARE
xNUMBER(5);
BEGIN
x := NVL2(10,20);
dbms_output.put_line(TO_CHAR(x));
END;
/
but you can write:
DECLARE
xNUMBER(5);
BEGIN
SELECTNVL2(10,20)
INTOx
FROMDUAL;
dbms_output.put_line(TO_CHAR(x));
END;
/ |
|
| SQLCODE |
Number of the most recent exception raised by PL/sql. 0 if none |
standard.sqlcodeRETURNPLS_INTEGER; |
set serveroutput on
BEGIN
dbms_output.put_line(sqlCODE);
END;
/
See Exceptions Page |
|
| SQLERRM |
Error message associated with the specified code |
standard.sqlerrm RETURNVARCHAR2;
standard.sqlerrm(code_in IN INTEGER := sqlCODE)RETURNVARCHAR2 |
set serveroutput on
BEGIN
dbms_output.put_line(sqlERRM);
END;
/
See Exceptions Page |
|
| SQL_GUID |
Generates and returns a globally unique identifier (RAW value) made up of 16 bytes. On most platforms,the generated identifier consists of a host identifier,a process or thread identifier of the process or thread invoking the function,and a nonrepeating value (sequence of bytes) for that process or thread. |
SYS_GUID()RETURNRAW |
CREATETABLEt (
ridRAW(32),
colVARCHAR2(20));
desc t
INSERTINTOt
(rid,col)
VALUES
(SYS_GUID(),'ABC');
INSERTINTOt
(rid,'DEF');
SELECT*FROMt; |
|
| SYS_TYPEID |
Returns the typeid of the most specific type of the operand |
SYS_TYPEID(<object_type_value>) |
CREATETYPEperson_tASOBJECT (nameVARCHAR2(30),ssnNUMBER)
NOTFINAL;
/
CREATETABLEpersons OF person_t;
INSERTINTOpersons
VALUES
(person_t('Morgan',123));
SELECTname,SYS_TYPEID(VALUE(p)) TYPE_IDFROMpersons p; |
|
| UID |
| User Session ID |
SELECTUID
FROMDUAL;
SELECTuser#
FROMgv$session
WHEREschemaname = USER; |
|
| USER |
| User As Logged On |
SELECTUSERFROMDUAL; |
|
| USERENV(deprecated: use SYS_CONTEXT) |
| Usage |
SELECTuserenv('<parameter>')
FROMDUAL; |
| Session info. stored with DBMS_APPLICATION_INFO |
SELECTUSERENV('CLIENT_INFO')FROMDUAL;
exec dbms_application_info.set_client_info('TEST');
SELECTUSERENV('CLIENT_INFO')FROMDUAL; |
| The current audit entry number. The audit entryid sequence is shared between fine-grained audit records and regular audit records. You cannot use this attribute in distributed sql statements. |
SELECTuserenv('ENTRYID')
FROMDUAL; |
| Current instance identifier |
SELECTuserenv('INSTANCE')
FROMDUAL; |
| ISDBA returns 'TRUE' if the user has been authenticated as having DBA privileges either through the operating system or through a password file. |
SELECTuserenv('ISDBA')
FROMDUAL; |
| The ISO abbreviation for the language name,a shorter form than the existing 'LANGUAGE' parameter. |
SELECTuserenv('LANG')
FROMDUAL; |
The language and territory currently used by your session,along with the database character set,in the form:
language_territory dot characterset. |
SELECTuserenv('LANGUAGE')
FROMDUAL; |
| The auditing session identifier. You cannot use this option in distributed sql statements. |
SELECTuserenv('SESSIONID')
FROMDUAL;
SELECTaudsid
FROMv_$session; |
| TERMINAL returns the operating system identifier for the terminal of the current session. In distributed sql statements,this parameter returns the identifier for your local session. In a distributed environment,this parameter is supported only for remote SELECT statements,not for remote INSERT,UPDATE,or DELETE operations. |
SELECTuserenv('TERMINAL')
FROMDUAL; |
|
| VALUE |
Takes as its argument a correlation variable (table alias) associated with a row of an object table and returns object instances stored in the object table. The type of the object instances is the same type as the object table. |
VALUE(correlation_variable) |
CREATETYPEaddress_tASOBJECT (
hnoNUMBER,
streetVARCHAR2(40),
cityVARCHAR2(20),
zipVARCHAR2(5),
phoneVARCHAR2(10));
/
CREATETYPEpersonASOBJECT (
nameVARCHAR2(40),
dateofbirthDATE,
homeaddress address_t,
manager REF person);
/
CREATEORREPLACETYPEperson_tASOBJECT (
nameVARCHAR2(100),
ssnNUMBER)
NOTFINAL;
/
CREATETABLEpersons OF person_t;
INSERTINTOpersonsVALUES(person_t('Bob',1234));
SELECTVALUE(p)FROMpersons p; |
