Data Small set of information becomes data, this set of information helps make decision. Data is always some useful information. Database Place where you store the data. Database represents some aspect of the real world called "miniworld". A database is designed, built and populated with data for a specific purpose. It has intended group of users and some preconceived applications in which these users are interested. In other words, a database has some source from which data is derived, some degree of interaction with events in the real world and an audience that is actively interested in the contents of the database. Database can also be defined as collection of one or more tables. Ex: Mobile, human brain etc DBMS (Database Management System ) Is a program that stores retrieves and modifies data in the database on request. Study of different techniques of design, development and maintenance of the database Types of DBMS These types are based upon their m...
Mithun Ashok's Experience, Summary, Trainings and Knowledge Sharing on Oracle Database, Oracle Applications, Fusion Middleware, SQL, PL/SQL and Database Testing
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1. Two tables emp (empid, name, deptid, sal) and dept(deptid, deptname) are there. Write a query which displays empname, corresponding deptname also display those employee names who do not belong to any dept.
2. Display the employees whose salary is less than average salary.
this is my mail id please froward it sir..
sayzaheer@gmail.com
1. SELECT e.ename, e.deptno, d.dname
FROM emp e, dept d
WHERE e.deptno (+) = d.deptno;
2. select * from emp where sal < (select avg(sal) from emp);
Have also sent this to your mail id.
Regards,
Mithun
select a.sal from emp a
where 0=(select count(*) from emp b
where b.sal>a.sal)
/
This is a co-related sub query. Please go through my presentation on Subqueries below.
SUBQUERIES
Regards,
Mithun
SELECT REPLACE(TRANSLATE(LTRIM(RTRIM('!! ATHEN !!','!'), '!'), 'AN', '**'),'*','TROUBLE') FROM DUAL;
we get this answer plz tel sir
TROUBLETHETROUBLE
Always innermost function gets executed first,
check below,
SQL> select RTRIM('!! ATHEN !!','!') from dual;
RTRIM('!!
---------
!! ATHEN
You are first doing RTRIM and removing all ! from right side.
Next,
SQL> select LTRIM('!! ATHEN','!') from dual;
LTRIM(
------
ATHEN
You have used LTRIM to remove ! from left.
SQL> select TRANSLATE(' ATHEN', 'AN','**') from dual;
TRANSL
------
*THE*
Now you are using TRANSLATE function to replace A with * and N with *.
SQL> select REPLACE(' *THE*','*','TROUBLE') from dual;
REPLACE('*THE*','*
------------------
TROUBLETHETROUBLE
Finally you are replacing * with TROUBLE.
Hope this is clear.
Regards,
Mithun
this is ravi here.
Would you please explain the following questions...
1>What is the advantage of JOINS over correlations??
2>Give some specific condition
when we should use joins and
when we should use correlation??