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

In my table i have 4 columns with 100 records but in that 4 columns one column contains all NULL values so can i add NOT NULL CONSTRAINT on that column......... ok if it is not possible, can i add NOT NULL CONSTRAINT from 101 Record Onwards?

Cap Gemini,

4 8189

How many null values can be inserted in a coulmn whihc is unique constraint

Flextronics,

8 13263

How is Oracle 10g helpful when compared to oracle 9i and what is grid computing

Flextronics,

1 5508

I want to insert userid of a customer,order time,etc in a table called ordermaster with orderid as primary key.Same time the product codes and required quantities (a1,2 and a2 4 and so on)inserted in another table orderdetails with same orderid reference.How the code will be in JSP using MySQL?

1913

* CREATE TABLE [dbo].[t_Colors]([ColorId] [int] NOT NULL,[ColorName] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL, [ColorDesc] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,[ColorIndex] [int] NULL) ON [PRIMARY] GO * insert into [t_Colors] values(101,'Red','',1) insert into [t_Colors] values(101,'Red1','',2) insert into [t_Colors] values(102,'Blue','',1) insert into [t_Colors] values(102,'Blue1','',2) insert into [t_Colors] values(102,'Blue2','',3) * In this table i need to delete DELETE FROM t_Colors WHERE ColorIndex=1 AND ColorId=102 After delete above condition i need to update the ColorIndex set to 1 for Blue1[ColorName] and 2 for Blue2[ColorName] select * from [t_Colors] Note:- how can i get updates the ColorIndex values after delete. for example we need to update Blue1 ColorIndex set to 1 and Blue2 ColorIndex set to 2

1893

wat wil hapn if we give the both read and deny read permission to user?

IBM,

2104

in my server i have 3 instances,one of them got failed, and this cause we r not able to connect to server, how to know which instance was dameged?

IBM,

1 4567

What is difference between stored procedure and function?

L&T,

3 7635

i have account table which consists of account name,card no and card no consists 16 digits now i want to retrieve the data if card no starts from 4 then it should print visa and if it starts from 5 then it should print master so plse help me to write simple query with out store procs .

3 5009

How to select top 5 coloumn from a table without using coloumn name

5 7907

What is the difference between SQL and PLSQL

IBM,

7 11270

the user should know to which database he is connected currently in oracle

3 4631

What is the difference between primary and unique key

CSC,

5 8242

what is the use of database index(apart from the last searching of records) and what is the use of composite key?

1 3704

query to retrive the employees whose sal is greater than avg sal

TCS,

10 15221

Un-Answered Questions { Databases }

Where can you add custom error messages to sql server?

1130

How do I completely uninstall postgresql?

872

Hey i want to join oracle apps so will you pls tell me that which institute is best in hyderabad.

2328

How can we identify the resources for which the sessions are waiting?

What is package in dbms?

887

What is the role of database server in database management system?

881

What is table partitioning in sybase?

903

What is a view? How it is related to data independence?

911

Does truncate remove indexes?

1038

What are the different types of replication you can set up in sql server?

1053

State the difference along with examples between Oracle 9i, Oracle 10g and Oracle 11i.

1035

How to create table with same structure of student table in mysql?

954

What are the differences between ms sql server & oracle?

1067

What do you mean by super key, primary key, foreign key and candidate key?

974

Mention what is olr?

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