DataBase Testing Interview Questions

Code
SELECT * FROM emp a WHERE (&n-1)=(SELECT count(DISTINCT b.sal) FROM emp b WHERE a.sal<b.sal);
 

Hi, To find the nth highest salary and find the second largest value in a given column as you asked both are same. So, both of the above scenarios the below is the query:

Code
SELECT * FROM table_name a WHERE &n=(SELECT count(DISTINCT(sal)) FROM Table_name b WHERE a.sal<b.sal);

Data redundancy means youre checking for duplication. In order to make that check, you need to determine what signifies a duplicate within the table to which you are referring. There is not a single q...

To conduct database testing the test engineers are following bellow issues:
1) Verification of data entered by the users through application at back end.
2) Verification of database design
3) Verifying the data integrity
4) Verification of SQL scripts.

For 22nd highest salary....

select * min(salary) from employee
where salary in(select distinct top 22 salary from employee order by salary desc)

Select * from (select *,Dense_RANK()over (order by salary column) SalayRank from tablename)A
where SalayRank=22

Ex:Select * from (select *,Dense_RANK()over (order by Emp_sal) SalayRank from Emp_a)A
where SalayRank=22

By this query you can achieve the first part of your question

Database testing involves the tests to check the exact values which have been retrieved from the database by the web or desktop application. Data should be matched correctly as per the records are stored in the database.

Hi Database testing mainly checks three things while testing : 1)Addition/Update data : In this scenario we are checking weather we the data is updated or added to the database when we do any modifi...

During testing oracles amis at Business System Testing which focuses on linking test requirements back to business requirements and securing project resources needed for testing. It supports utilizin...

select ename,dept,sal from emp group by ename having dept order by sal

The Transact-SQL commands most often used by a tester are:USE database_name SELECT column_names FROM table_nameSELECT DISTINCT column_name FROM table_name'SELECT column_name FROM table_name W...

Join: We can display data from two or more than two table using Join.

There are 4 Types of Join-
1) Natural Join
2) Inner Join
3) Outer Join
4) Cross Join

Outer Join is further divide into two types-
1) Left outer join
2) Right Outer Join

May I suggest internet?

Check database integrity Check the allocation and structural integrity of user and system tables, and indexes in the database, by running the DBCC CHECKDB Transact-SQL statement. This ensures that a...

@ dugulam: I would have agreed with your answer if both the databases were of the same type. Meaning if both the DBs were Oracle or both were SQL Server. But, the example in the question involved diff...

u can extract data from different table using the joins in sql

using inner join
         outer join etc.

Ok lets do this by taking an example. Lets say you are testing the integration between database and a user registration web application. User registration web site becomes your front-end and database...

For writing test cases in Database first one should define the project name, then module,Bug number,objective,steps/action undertaken,expected result,actual result, then status, priority and severity.

SELECT ssn_no, LENGTH(ssn_no) FROM Customer_Info

select ID from test where ID Between 9999 and 100000

you can try this out also.....

1. No of tables in both old and new should be same2. Table structures in both old and new should be same.3. If it's a Data nmigration to , then ned to compare the no of records in all the tables i...

We need to check out what was all the enhancement the SQL Server 2008 has in it.  We need to design our testcase considering the following points.1.      Data type used2....

Suppoe there is table called SOURCE, conatins column NAME and AGE.  The reuirement is that to poulate records from SOURCE to the target tale TARGET. In TARGET table contain following co...

Select * from EMP where EMP_DOJ = 010110Here EMP is the Table name,EMP_DOJ is the date of joining of the Employee in EMP table.If any record/records found with DOJ as 010110,it will retrive all the re...

Cross Verify the front end changes reflection in case of Add, update and Delete operatiomn of any field.

it confirms that your changes made by application saves successfully

Database Testing deals with the following:-1) Testing the data in the Database for Feed/Flat File data based on the requirements by writing medium to complex queries using SELECT, INNER JOINS/OUTER JO...

Hi Raghu,

The answer you gave is very useful,. but can you be a bit more elaborative as of to what extent do we need to work with indexes, cursors and how to test a SP with some examples if possible!!

Thanks
Rajani

In DB Testing we validate the proper data is maintained at Backend. We also validate the Stored Procedure return the expected result. And we also perform the Data migration migration means upgrade testing on DB like upgrade DB from SQL 2005 to SQL 2008....

Data migration is translation of data in the tables from one db to another or is can also be from one format to another format.Checks needed are,Need to identify the source table in source db & de...

Data migration testing is to compare migrated data with original data to find out any discrepancies. Database Migration Testing: 1. We have to check database integrity. 2. We have to check the referen...