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 

SQL >> rename table_name1 to new_table_name;

alter table table_name_old rename to table_name_new;

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);

Code
SELECT REPLACE(TRANSLATE(LOWER(99sAmn44423mz44),abcdefghijklmnopqrstuvwxyz, ), ,) FROM dual 

Code
SELECT columnname FROM tablename WHERE regexp_like(columnname,^[[:digit:]]+$) ;

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...

In SQL 2005 only != and <> operator perform same operation

^= does not work

^= operator is a Bit wise Exclusive OR operater in MS SQL.
It stands into category of compound operators and performs a bitwise exclusive OR and sets the original value to the result.

Varchar - If we declare datatype as varchar then it will occupy space for null values. It can store upto 2000 bytes of character.

Varchar2 - If we declare datatype as varchar2, it will not occupy any space. It can store 4000 bytes of character.

Thanx,

Difference b/w varchar and varchar2 is varchar is ANSI standard and varchar2 is a Oracle data type
and also varchar is fixed length record, varchar2 is variable length.

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...

SQL is command line argument. You can access data into database to write procedure.

what are the 12 rules of CODD

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

ORACLE organises the database of collection data and this data retrieve from sql .So sql is a language but sql-server is a product of Microsoft which support sql.

SQL is a language which is used to retrieve and manipulate data in database .... SQL Server is the relational data base management system, a product from Microsoft.