Learn SQL

Home >> Learn SQL

Learn SQL

The following SQL topics will help you to learn SQL in an easy way. This SQL Tutorial almost covers all the topics required for a basic understanding of SQL.

 Basics

Basics Table Queries
Clauses
Operators
Functions
Keys
Joins
Other Topics
Please leave a comment below if you like this post or found some error, it will help me to improve my content.
By

Comments

Post a Comment

Popular Posts from this Blog

Anti Diagonals - The Coding Shala

Image
Home >> Interview Questions >> Anti Diagonals Anti Diagonals Java Solution Give an N*N square matrix, return an array of its anti-diagonals. Look at the example for more details. Example: Input: 1 2 3 7 8 9 4 5 6 Return the following : [ [1], [2, 4], [3, 5, 7], [6, 8], [9] ] Input : 1 2 3 4 Return the following : [ [1], [2, 3], [4] ] Anti Diagonals Java Solution 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 public class Solution { public ArrayList < ArrayList < Integer >> diagonal ( ArrayList < ArrayList < Integer >> A ) { ArrayList < ArrayList < Integer >> ans = new ArrayList < ArrayList < Integer >>(); int N = A . size (); int i = N - 1 ; while ( i >= 0 ){ ArrayList < Integer > tmp = new ArrayList < Integer >(); ...
Read more

First Missing Positive Solution - The Coding Shala

Home >> Interview Prep >> First missing positive  In this post, we will learn how to solve the First Missing Positive problem and will implement its solution in Java. First Missing Positive Problem Given an unsorted integer array nums, find the smallest missing positive integer. You must implement an algorithm that runs in O(n) time and uses constant extra space. Example 1: Input: nums = [1,2,0] Output: 3 Example 2: Input: nums = [3,4,-1,1] Output: 2 First Missing Positive Java Solution Approach 1 Time Complexity: O(n) Space Complexity: O(1) The steps are below to solve this problem: Step 1: The first missing positive number will be in the range of 1 to N+1, where N is the length of the array. So Other than these numbers we can ignore, make this change in the array. Step 2: Now we will take the array elements as the index(their original position), and at the numbers' original position will make the array element negative so later we can check this number ...
Read more

Shell Script to Display the digits which are at odd positions in a given 5-digit number - The Coding Shala

Home >> Scripting >> Odd position digits Shell Script to Display the digits which are at odd positions in a given 5-digit number Display the digits which are at odd positions in a given 5-digit number.   Example: number is 23786 output - 276. Code:  #! / bin / bash echo "enter 5 digit number" read number n= 1 while ((n < = 5 )) do a =`echo $number | cut - c $n` echo - n "$a" n=`expr $n + 2 ` done echo " " Other Posts You May Like Shell script to add two numbers using command line argument Shell script to generate Fibonacci series Shell script to find factorial of a number Shell script to print a number in reverse order Shell script to create a simple calculator Please leave a comment below if you like this post or found some error, it will help me to improve my content.
Read more

Longest Substring Without Repeating Characters Java Program - The Coding Shala

Home >> Interview Questions >> Longest Substring without repeating characters Longest Substring Without Repeating Characters Java Program In this post, you will learn how to find the length of the longest substring without repeating characters in a string and its Java solution. Given a string, find the length of the longest substring without repeating characters. Example 1: Input: "abcabcbb" Output: 3 Explanation: The answer is "abc", with a length of 3. Example 2: Input: "bbbbb" Output: 1 Explanation: The answer is "b", with a length of 1. Example 3: Input: "pwwkew" Output: 3 Java Solution of Longest Substring without Repeating Characters Approach 1: Using brute force by checking all the substrings.  We'll use HashSet to check if characters are unique or not. Time complexity: O(n^2) Space Complexity: O(n) Java Program:  class Solution { public i...
Read more

LeetCode - Swap Nodes in Pairs Solution - The Coding Shala

Home >> LeetCode >> Swap Nodes in Pairs LeetCode - Swap Nodes in Pairs Solution In this post, you will learn how to solve LeetCode's Swap Nodes in Pairs problem with Java Solution. We will solve this problem using recursion and iteration. Given a linked list, swap every two adjacent nodes and return its head.  You may not modify the values in the list's nodes, only nodes itself may be changed. Example: Given 1->2->3->4, you should return the list as 2->1->4->3. Practice this problem on  LeetCode(Click Here). Swap Nodes in Pairs Java Solution Approach 1: Iterative Solution. Java Program:  /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ class Solution { public ListNode swapPairs ( ListNode head ) { //check for null or 1 node if ( head == null || head . next == n...
Read more