ashok panguluri

• Feb 11th, 2012

Primary key: The key which is unique and not allow the null values nothing but primary key. Each table contain only one primary key.

Candidate key: The key which is opt for the primary key is nothing but candidate key, the table can contain number of candidate key as per requirement.

srikanth.cherukupalli

 Profile Answers by srikanth.cherukupalli Questions by srikanth.cherukupalli

• Jan 12th, 2012

Primary key defines the uniqueness of a row. there should be no null value in primary key. The keys which are opt for primary key known as candidate keys. In a table candidate keys are the candidates...

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Hi Friends, One table having some many records but I want to retrieve under little-bit records randomly. If it is possible in SQL then send the reply ? So, I will wait for ur valuable answer...

Balapradeep Reddy

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• Feb 14th, 2012

Code
 

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display the 5th lowest sal from emp table using Correlated subquery

sampra

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• Mar 6th, 2012

Select * from Hello h where 5=(select count (distinct amt) from hello where h.amt>amt)

This will give the 5th record from lowest

srikanth.cherukupalli

 Profile Answers by srikanth.cherukupalli Questions by srikanth.cherukupalli

• Mar 1st, 2012

Select rank,salary from (select rownum as rank, salary from (select distinct(salary) from emp order by salary)) where rank=5;

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muralir02  

 Profile Answers by muralir02 Questions by muralir02

• Member Since Mar-2006 | Mar 20th, 2006

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select max(sal) from emp where sal<(select max(sal) from emp);

sampra

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• Mar 6th, 2012

Select salry from Hello h where 2=(select count (distinct salry) from hello where h.salry

srivathson

• Feb 20th, 2012

Code
 

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sampra

 Profile Answers by sampra Questions by sampra

• Mar 6th, 2012

Select * from emp where rowid=(select max(rowid) from emp);

ANURAG PURANIK

• Jul 29th, 2006

Select *  from emp where rowid=(select max(rowid) from emp);

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sampra

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• Mar 6th, 2012

Select salry from Hello h where 1=(select count (distinct salry) from hello where h.salry

maqsood

• Jul 10th, 2006

Select last_name from employeesWhere rownum

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sampra

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• Mar 6th, 2012

Cluster index stores the data ordering wise Ascendingly.
suppose u have inserted the data started on A,B, and D and now if any person will enter the data started from C then the entries for D data would be changed to next locations

It would changes the whole structure of the tabel

Sanjay Agrawal

• May 30th, 2006

Cluster index just changes the whole physical structure of the Tablethe data of table is stored in the data pages they are 8 kb pages.Cluster index stores the data ordering wise Ascendingly.suppose u ...

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Semicolon ' ; '

sampra

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• Mar 6th, 2012

Semicolon

C.A.MURALI MOHAN

• Feb 28th, 2006

By using semicolon we can terminate the query.

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How data is stored in database?

sampra

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• Mar 6th, 2012

All data are stored in o and 1 format means binary form

anjali

• Jul 28th, 2011

All data are stored in o and 1 format means binary form

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sampra

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• Mar 6th, 2012

Create table emp as select * from student where 1=2;

Satish Kopalle

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• Jun 7th, 2011

select * from faculty where rownum=0;

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sampra

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• Mar 6th, 2012

Select * from hello h where 1=(select count(discnt amt) from hello where h.amt

nirmal1in

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• Dec 25th, 2010

Say for example below are data exist on EMP tableEMPNO  EMPNAME                DEPTNO      ...

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How Create Index in Oracle? explain with example

sampra

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• Mar 6th, 2012

Create index cr_ind on student(sid);
here i have created a index on student table on column sid

prashant.baranwal

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• Sep 16th, 2010

The CREATE INDEX statement is used to create indexes in tables. Indexes allow the database application to find data fast; without reading the whole table. CREATE INDEX index_name ON table_name (c...

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..........

sampra

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• Mar 6th, 2012

SQL is a language to insert update delete the record where oracle is a database

vijaypati

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• Mar 3rd, 2010

SQL stands for Structured Query Language. SQL is used for accessing and manipulating databases. SQL can execute queries against a database. SQL can Retrive, insert, update & delete from ...

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How to count the number of constraints on a given table?

sampra

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• Mar 6th, 2012

Select count(constraint_name) from user_constraints where table_name=TABLENAME

itoradeveloper

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• Jan 6th, 2010

Select count(constraint_name) from user_constraints where table_name='TABLENAME'

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How to secure SQL scripts so that they cannot be seen by others but can only be executed.

sampra

 Profile Answers by sampra Questions by sampra

• Mar 6th, 2012

Create a view and give the permission for select only

rahul kiran

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• May 16th, 2009

Create a view and remove all the privilages except select on that view

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How to create table emp1 based on emp, except comm column?

sampra

 Profile Answers by sampra Questions by sampra

• Mar 6th, 2012

CREATE TABLE emp1 AS (SELECT empno, ename, hiredate, s

nathsambu

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• Dec 19th, 2008

Create table emp1 as select * from emp;

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How can I copy the stucture of a table to a text file.

sampra

 Profile Answers by sampra Questions by sampra

• Mar 6th, 2012

Create table ABC as (select * from XYZ where 1=2)

krishnaindia2007

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• Jun 21st, 2008

You can copy the definition of objects to text file using dmbs_metadata package.This is the query to copy emp table definition to text file.spool textfilenameselect dbms_metadata.get_ddl('TABLE','EMP','CMSJAN') from dual;spool off;

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How to delete contents in two tables at a time? When you delete contents in one table then other table contents should also be deleted.

sampra

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• Mar 6th, 2012

1> always avoid select * from
2> do not use in operator

krishnaindia2007

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• Jun 20th, 2008

You may also use triggers for this purpose. But specifying on delete cascade while defining foreign key constraint is better option.

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How can you tune the query?

sampra

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• Mar 6th, 2012

1> always avoid select * from
2> do not use in operator

Imran_Javed

 Profile Answers by Imran_Javed Questions by Imran_Javed

• May 8th, 2008

First look at the explain plan if there is any full scan. Then add appropriate index on columns that are used in the query. Basically, always add index on foreign key and the date columns (Most of the application access tables based on dated)

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How to desc table data without using desc command

sampra

 Profile Answers by sampra Questions by sampra

• Mar 6th, 2012

No ways

saradajasti

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• Mar 24th, 2008

Select column_name name,data_type typefrom user_tab_columnswhere table_name =

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