Databases Interview Questions, Answers for Freshers and Experienced asked in various Company Job Interviews

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Databases Interview Questions

Questions Answers Views Company eMail

select trunc(round(156.00,-1),-1) from dual;

2 31121

hi,i plan to put experience on PLSQL ,can anyone suggest me for any institutes in bangalore or how to prepare for interviews

1992

when we are importing items in inventory, showing errors, Oracle support suggested us for running scripts & also suggested if we run scripts, iprocurement applicaation if is there it will show shared and if we go in future for iprocurement, it wont work. So kinldy suggest any functional solution.

1950

any body know about orawaves do they really provide placements in their unique placement program

TCS,

1 4054

Table - Products has number of products as below Productid ProductName 1 iPhone 2 iPad 3 BlackBerry Table - SalesPersonProduct has the below records Salespersonid productid S1 1 S1 2 S1 3 S2 1 S3 2 Write a SQL query that returns the total number of sold products

2782

2 6538

what is tkprof tool and how it is used???

Genpact,

2793

how do see how much space is used and free in a tablespace

Genpact,

2 7659

1. how do you delete duplicate rows in a table? 2. can you disable and enable primary key? 3. how do you move tables from one tablespace to another tablespace?????

Genpact,

2 6582

primary key is foreign key for the same table?

Oracle,

2 7081

Hi All, I am new to both this blog and technology. I was able to see a response for one of the questions on triggers as below. I would like to know why are we using " if rtrim(to_char(sysdate,'day'))=rtrim('sunday') then" instead, can't we use " if sysdate = 'sunday' then". I can understand the use of "rtrim", but dont know y v r using to_char. I have seen this in many cases but did not get a convincible explaination. Please help me with this and do excuse if this question sounds silly. Thanks in advance...... create or replace trigger trg_sun before insert on

begin if rtrim(to_char(sysdate,'day'))=rtrim('sunday') then raise_application_error(-20345,'no transaction in sunday'); end if; end trg_sun;

2 4227

I want to reuse a piece of code inside a stored procedure. This piece of code need to be invoked multiple times inside the procedure based on some different conditions. How to achieve this?

1 3883

1) What is dense ranking? 2) Difference between Substring and Instring? 3) Case and Decode? 4) Pseudo column? 5) View vs Materialized views? 6) SQl performance tuning?

Accenture,

2 6890

how to check the 3rd max salary from an employee table? One of the queries used is as follows: select sal from emp a where 3=(select count(distinct(sal)) from emp b where a.sal<=b.sal). Here in the sub query "select count(distinct(sal)) from emp b where a.sal<=b.sal" or "select count(distinct(sal)) from emp b where a.sal=b.sal" should reveal the same number of rows is in't it? Can any one here please explain me how is this query working perfectly. However, there is another query to get the 3rd highest of salaries of employees that logic I can understand. Pls find the query below. "select min(salary) from emp where salary in(select distinct top 3 salary from emp order by salary desc)" Please explain me how "select sal from emp a where 3=(select count(distinct(sal)) from emp b where a.sal<=b.sal)" works source:http://www.allinterview.com/showanswers/33264.html. Thanks in advance Regards, Karthik.

4 8276

Display the total debit counts, total credit counts, sum of total debits, sum of total credits from an employee's transaction table (a single table) containing the following columns. Transaction_number Transaction_amount Transaction_date Transaction_type --> tells if the amount is a credit or a debit. As the query alone is important, the table is left with specifying just the field's name. Pls help me with this query.

iNautix, Oracle,

3 17723

Un-Answered Questions { Databases }

What is the default port for mysql and how it can change?

1019

How to create a simple table to test triggers in ms sql server?

928

Why do we need foreign key?

821

What is an index in a database?

930

What are “lost updates”?

958

What are the main benefits of using spfile over pfile?

594

How to load data from external tables to regular tables?

1005

How do you delete a row in a table?

719

Explain the use of tables option in exp command.

1066

What the different topologies in which replication can be configured? : sql server DBA

1193

What are sql azure firewall rules?

106

Explain about the return statement?

837

Can multiple users access the same access database?

828

What Is Rdbms?

1095

What is the purpose of update statistics and scope_identity() function?

1064

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