SQL Interview Questions

Code
SELECT rownum,a.*FROM(SELECT rownum,b.*FROM emp b ORDER BY rownum DESC) a WHERE rownum <&n;

For First N Rows:

Ypu need to know MR. SQL that you cant use = operator with rownum ....

Code
SELECT * FROM emp a WHERE (&n-1) =(SELECT count(UNIQUE sal) FROM emp b WHERE a.sal>b.sal) FOR nth minimum salary
SELECT * FROM emp a WHERE (&n-1) =(SELECT count(UNIQUE sal) FROM emp b WHERE a.sal<b.sal) FOR nth maximum salary 

Please tell me,
How to get age of all employee by using query

      SELECT *,DATEDIFF(YY,,GETDATE()) AS AGE FROM WHERE DATEDIFF(YY,,GETDATE()) > 30




  Thanks & Regards
  K.santhosh

We delete the duplicate records using level and rownum. The query is

Code
DELETE FROM emp WHERE ROWNUM IN(SELECT MAX(ROWNUM) FROM emp WHERE LEVEL=nth CONNECT BY PRIOR empno>empno GROUP BY LEVEL);

1 Delete from table_name where ROWID not in ( select

max(rowid) from table group by duplicate_values_field_name);

I believe what you are looking for is a query like this:

select f3.deptname dept_name, sum(isnull(f2.salary,0)) amt_spent_each_dept
from file3 f3 left join file1 f1 on (f3.deptid = f1.deptid)
left join file2 f2 on (f1.empid = f2.empid)
group by f3.deptname
order by f3.deptname

Force view creates the view even if the underlying tables / referenced objects are not present. Force View are used while executing a script that has create tables and views statements or while creating a view for remote table.

1.Auditing the tables
2.Online transaction
3.Securing from another table
4.Automatic calculations
5.Replicate the tables

The main advantages of the triggers are

* To Audit the table

* To check the complex conditions which are not possible by the constraints.

Normalization--To Reduce or to remove the redundancy in table we used Normalization and the normalization we can achieve by breaking of tables by this table is in Normalized.

0NF "sql CUSTOMER ORDER (CustName, OrderNo, ProdNo, ProdDesc, Qty, CustAddress, DateOrdered) 1NF - remove multivalued attributes "sql CUSTO...

Sub query: A sub query is executed once for the parent statement. Correlated Sub query: Correlated sub query runs once for each row selected by the outer query. It contains a reference to a value fr...

select date1-date2 from tablename;

If the above value is negative it means date 1 is older than date 2

Mr. Chandu can you give some example code. I am not clear with the code you have posted.

You can use BEFORE < col name >
or
AFTER < col name >
or
< col name > 2

Here 2 is the position that the new col is about to place.

Code
SELECT * FROM `table_name` WHERE rownum <> 1 ORDER BY rownum  ASC LIMIT 1; 

the best way to issue is

select top 1 * from cars where id_car in
(select top 2 id_car from cars order by id_car)
order by id_car DESC

and with that
obtain the second record (This way is for the PK)

if we are dong select top 33* from table, we will get topmost 33 records but not the all 33 columns except 1 column in a table.

select top 19 * from table1

its not clear...... it will be execute correctly?

delete from table_name where rowid not in (SELECT max(rowid) FROM table_name group by (column_name))

If the evaluation of an inner query(a sub query) depends on a variable which gets its value in an outer query,such a subquery has to be evaluated for each value of the variable.Such a query is a corre...

If the evaluation of an inner querry(a sub querry) depends on a variable which gets its value in an outer querry,such a subquerry has to be evaluated for each value of the variable.Such a querry is a ...

Supplier Table Columns : Supplier id , supplier name (Supplier ID, supplier name as Primary Key) Supplier Site Details Columns : Supplier name , site, street, city, state (Supplier name as foreign Ke...

First to define what Inner Join and Outer Join mean. Inner Join: A join between two tables were only those records in both tables that meet the conditions of the join expression are returned. In most...

If you want is not created a user with command line, you should create it with the interface

Use Grant command to create user and giving permission.

SELECT ename FROM employee WHERE (address1<>'' OR address2<>'' OR address3<>'' )

As far as i know use concatenation operator...

Code
SELECT ename AS name,address1 || ',' ||address2||','||address3 AS address FROM employee

It's like WHERE clause but "HAVING" It is more commun to use with GROUP BY

Having clause is used filter data which is retrieve by group by clause.for example: if you try to use having to filter data instead of where clause then it fires error.the style of query is:- 1...