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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Please find the links for all the presentations on SQL Basics.
http://www.mithunashok.com/2011/03/sql-basics-intro.html
http://www.mithunashok.com/2011/03/sql-basics-basic-select-statement.html
http://www.mithunashok.com/2011/03/sql-basics-restricting-and-sorting-data.html
http://www.mithunashok.com/2011/02/sql-basics-presentation.html
Regards,
Mithun
Thats a great news. CONGRATULATIONS!!!
Its all your hard work.
All the best for your future.
Best Regards,
Mithun
i got error while executing the nth maxsalary query...the query wat i executed is given below.i executed the query in sqlplus8.0....if i execute the 1st inner query its working but the 2nd one is not workin sir..find me the solution sir...
SQL> select salary from(select rownum ranking, sal salary from (select distinct(sal)
2 from emp where sal is not null order by sal desc)) where ranking = 3;
from emp where sal is not null order by sal desc)) where ranking = 3
*
ERROR at line 2:
ORA-00907: missing right parenthesis
Max salary query works fine. Let me know the db version you are trying to execute this.
Mithun
1)select length('salesman') from dual minus select length(replace('salesman','s','')) from dual
it is giving 8 as length.but it should be 2.is it not sir?my intension is to count the number of 's' es.
2)pls explain union,unionall,index,view with examples
how to use rank pls explain with an example
1. Do not use 'minus' clause to get the result that you are expecting. MINUS clause is used as one of the set operators check my presentation Link
To get the answer you need use arithmetic operator - instead of MINUS.
2. Refer to the same presentation above on UNION and other set operators.
An index is a performance-tuning method of allowing faster retrieval of records.
View in Oracle and in other database systems is simply the representation of a SQL statement that is stored in memory so that it can be easily reused.
CREATE VIEW emp2 as select ename,sal from emp;
3. RANK calculates the rank of a value in a group of values. The return type is NUMBER.
SELECT RANK(3000) WITHIN GROUP
(ORDER BY salary DESC) "Rank of 3000" FROM emp;
1. Do not use 'minus' clause to get the result that you are expecting. MINUS clause is used as one of the set operators check my presentation Link
To get the answer you need use arithmetic operator - instead of MINUS.
2. Refer to the same presentation above on UNION and other set operators.
An index is a performance-tuning method of allowing faster retrieval of records.
View in Oracle and in other database systems is simply the representation of a SQL statement that is stored in memory so that it can be easily reused.
CREATE VIEW emp2 as select ename,sal from emp;
3. RANK calculates the rank of a value in a group of values. The return type is NUMBER.
SELECT RANK(3000) WITHIN GROUP
(ORDER BY salary DESC) "Rank of 3000" FROM emp;
it is giving 8 as length.but it should be 2
sir i am not getting how to use arithmetic operators.pls write the query
You have to write the statement as shown below below,
select length('salesman') - length(replace('salesman','s','')) from dual;
Mithun