Skip to main content

4 Qs 4 Answers


1. How can I get recent 10 records out of 100 records?
SELECT *
FROM (Select *
from employee
order by rowid desc)
WHERE ROWNUM < 11

2.When would you use inline view in sub query?


You may use inline view when you want to cut short multi-join of tables.


3. How to select the recently updated records from the table?
 
There is no provision you can use to find out the records from the table. You may use auditing tables with the help of Triggers.

Use the date function to achieve the results.
select to_char(to_date(999999,'j'),'jsp') from dual;

But it is better you write your own translate function because it doesnt support beyond 999999. 
Higher range might work in 64-bit OS.


Comments

Popular posts from this blog

Design and Operations ( Employee- Model )

-- DB design drop table emp_Salary; drop table emp_Designation; drop table emp; drop table Designations; drop table Departments; drop table Salary_Bands; drop table Addresses; Create table emp( emp_id number, emp_Name varchar2(20), emp_address_id varchar2(10), emp_created_date date, emp_created_by varchar2(20), constraint e_pk primary key(emp_id) ); Create table Departments( dept_id number, dept_name Varchar2(20), constraints dept_pk primary key(dept_id) ); Create table Designations( dept_id number references Departments(dept_id), desg_id number, desg_description varchar2(20), constraints desg_pk primary key(dept_id,desg_id) ); Create table emp_Designation( emp_id number references emp(emp_id), emp_des_dept_id number references departments(dept_...

Minimum / Maximum from the given list

File: Execute.java -------------------------------------------------------------------------------------- package org.developersbrain.Solutions; public class Execute { public static int min(int[] arrList){ int minV1=0; int minV2=0; int aLen=arrList.length; minV1=arrList[0]; minV2=arrList[aLen-1]; for(int i=0,j=aLen-1;i&lt;=aLen/2;i++,j--){ if(minV1 &gt; arrList[i]){ minV1=arrList[i]; } if(minV2 &gt; arrList[j]){ minV2=arrList[j]; } } if(minV2&lt;=minV1){ return minV2; }else{ return minV1; } } public static int max(int[] arrList){ int minV1=0; int minV2=0; int aLen=arrList.length; minV1=arrList[0]; minV2=arrList[aLen-1]; for(int i=0,j=aLen-1;i&lt;=aLen/2;i++,j--){ if(minV1 &lt; arrList[i]){ minV1=arrList[i]; } if(minV2 &lt; arrList[j]){ minV2=arrList[j]; } } if(minV2&gt;=minV1){ return minV2; }else{ return minV1; } } ...

SQL - Binary Search Tree

Problem Statement You are given a table,   BST , containing two columns:   N  and   P,  where   N   represents the value of a node in   BST , and   P   is the parent of   N . Write a query to find the node type of   BST   ordered by the value of the node. Output one of the following for each node: ·          Root : If node is root node. ·          Leaf : If node is leaf node. ·          Inner : If node is neither root nor leaf node. Sample Input                 N          P 1 2 3 2 6 8 9 8 2 5 8 5 5         null Sample Output 1 Leaf 2 Inner 3 Leaf 5 Root 6 Leaf 8 Inner 9 Leaf Explanation The   BST ...