A SUB-QUERY IN THE WHERE CLAUSE OF A SELECT STATEMET IS CALLED AS NESTED SUB-QUERY; A SUB-QUERY IN THE FROM CLAUSE OF A SELECT STATEMET IS CALLED AS INILINE VIEW; --> ORACLE IMPOSES NO LIMIT ON THE NUMBER OF SUB-QUERY LEVELS IN THE FROM CLAUSE; -->WITH IN THE WHERE CLAUSE UPTO 255 SUB QUERYS CAN BE NESTED ; SUB-QUERY PRINCIPLE: ------------------- SLOVE PROBLEM BY COMBINING THE TWO QUERIS ,PLACEING ONE QUERY INSIDE THE OTHER QUERY SYNTAX: ------ SQL> SELECT SELCTLIST FROM TABLENAME WHERE COLUMNAME OPERATOR ( SELECT SELCTLIST FROM TABLENAME );
A SUB-QUERY IN THE WHERE CLAUSE OF A SELECT STATEMET IS CALLED
AS NESTED SUB-QUERY;A SUB-QUERY IN THE FROM CLAUSE OF A SELECT
STATEMET IS CALLED AS INILINE VIEW;
--> ORACLE IMPOSES NO LIMIT ON THE NUMBER OF SUB-QUERY LEVELS
IN THE FROM CLAUSE;-->WITH IN THE WHERE CLAUSE UPTO 255 SUB
QUERYS CAN BE NESTED ;
SUB-QUERY PRINCIPLE:------------------- SLOVE PROBLEM BY
COMBINING THE TWO QUERIS ,PLACEING ONE QUERY INSIDE THE OTHER
QUERYSYNTAX:------ SQL> SELECT SELCTLIST FROM TABLENAME WHERE
COLUMNAME OPERATOR ( SELECT SELCTLISTFROM TABLENAME );
THE EXPRESSIONAL OPERATOR IN SUB QUERIS CAN BE TWO
TYPES:---------------------------------------------------------------
1) SINGLE ROW OPERATORS -->(=,,=)2) MULTY ROW OPERATORS
---> (IN ANY ALL)TYPES OF SUB QUERIS:-------------------1)
SINGLE ROW SUB QUERIS:THESE QUERIES RETURN ONLY ONE ROW FROM THE
INNER SELECT STATEMET.2) MULTIPLE ROW SUB-QUERIES: THESE QUERIS
RETURN ONLY MORE THEN ONE ROW FROM THE INNER SELECT STATEMET3)
MULTIPLE COLUMN SUB-QUERIES:THESE QUERIS RETURN ONLY MORE THEN ONE
COLUMN FROM THE INNER SELECT STATEMET1) SINGLE ROW SUB QUERIS:
