Select From Table Where Value Does Not Exist with MySQL

AmitDiwan
Updated on 02-Jan-2020 05:22:00

886 Views

For this, you can use NOT IN() −mysql> create table DemoTable1991 (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentName varchar(20) ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1991(StudentName) values('Chris'); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable1991(StudentName) values('Bob'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1991(StudentName) values('David'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable1991(StudentName) values('Sam'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1991(StudentName) values('Mike'); Query OK, 1 row affected (0.11 sec)Display all ... Read More

Print Hut in C++

Ayush Gupta
Updated on 02-Jan-2020 05:20:47

310 Views

In this tutorial, we will be discussing a program to print a Hut pattern.For this, we will be provided with the width of the hut to be printed (say N). Our task is to print a hut structure of the given width using stars and a gate inside the hut using line characters.Example Live Demo#include using namespace std; //printing the given hut structure int print_hut(int n){    int i, j, t;       if (n % 2 == 0) {          n++;       }       for (i = 0; i = n / 5)             || (j >= n / 5 && j < n - n / 5 && i == 0)             || (j == 0 && i >= n / 5)             || (j == t && i > n / 5)             || (i

Select Dates That Are One Week Ahead from Today in MySQL

AmitDiwan
Updated on 02-Jan-2020 05:19:12

359 Views

To get dates that are one week ahead from today, use DATEDIFF. Let us first get the current date −mysql> select curdate(); +------------+ | curdate()  | +------------+ | 2019-12-20 | +------------+ 1 row in set (0.00 sec)We will first create a table −mysql> create table DemoTable1990    (    ShippingDate date    ); Query OK, 0 rows affected (0.99 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1990 values('2019-12-13'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1990 values('2019-12-21'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1990 values('2019-12-20'); Query OK, 1 ... Read More

Convert Varchar Data to MySQL Date Format

AmitDiwan
Updated on 02-Jan-2020 05:17:18

761 Views

To convert VARCHAR data to date format, you can use STR_TO_DATE() −mysql> create table DemoTable1989    (    DueDate varchar(20)    ); Query OK, 0 rows affected (0.91 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1989 values('31/01/2015'); Query OK, 1 row affected (0.52 sec) mysql> insert into DemoTable1989 values('01/12/2018'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable1989 values('25/10/2019'); Query OK, 1 row affected (0.11 sec)Display all records from the table using select statement −mysql> select * from DemoTable1989;This will produce the following output −+------------+ | DueDate    | +------------+ | 31/01/2015 | ... Read More

Alternative of WHERE Clause for Each SELECT Field in MySQL

AmitDiwan
Updated on 02-Jan-2020 05:15:50

530 Views

You can use CASE statement −mysql> create table DemoTable1988    (    Value1 int,    Value2 int,    Price int    ); Query OK, 0 rows affected (0.64 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1988 values(10, 7, 500); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable1988 values(7, 9, 400); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1988 values(8, 7, 200); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable1988 values(7, 4, 300); Query OK, 1 row affected (0.16 sec)Display all records from the table using select ... Read More

Convert Date Timestamp to Return Month Number

AmitDiwan
Updated on 02-Jan-2020 05:13:03

246 Views

To return only the month number, you can use DATE_FORMAT() -mysql> create table DemoTable1999    (    ArrivalDate timestamp    ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1999 values('2019-01-01 12:34:00'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1999 values('2019-12-31 10:04:00'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1999 values('2018-10-11 04:04:30'); Query OK, 1 row affected (0.14 sec)Display all records from the table using select statement −mysql> select * from DemoTable1999;This will produce the following output −+---------------------+ | ArrivalDate         ... Read More

Maximum Element Between Two Nodes of BST in C++

Narendra Kumar
Updated on 31-Dec-2019 13:39:16

283 Views

Problem statementGiven an array of N elements and two integers A, B which belongs to the given array. Create a Binary Search Tree by inserting element from arr[0] to arr[n-1]. The task is to find the maximum element in the path from A to B.ExampleIf array is {24, 23, 15, 36, 19, 41, 25, 35} the we can form BST as follows −If we consider A = 19 and B = 41 then maximum element between these two nodes is 41AlgorithmFind Lowest Common Ancestor(LCA) of node A and B.Find maximum node between LCA and A. Let us call it as ... Read More

Maximum Edge Removal from Tree to Make Even Forest in C++

Narendra Kumar
Updated on 31-Dec-2019 12:28:10

453 Views

Problem statementGiven an undirected tree which has even number of vertices, we need to remove the maximum number of edges from this tree such that each connected component of the resultant forest has an even number of vertices.ExampleIn above shown tree, we can remove at max 2 edges 0-2 and 0-4 shown in red such that each connected component will have even number of vertices.AlgorithmDo DFS from any starting node as tree is connectedInitialize count of nodes in subtree rooted under current node as 0Do following recursively for every subtree of current node −If size of current subtree is even, ... Read More

Maximum Determinant of a Matrix with Values 0 or N in C++

Narendra Kumar
Updated on 31-Dec-2019 12:22:55

151 Views

Problem statementWe have given a positive number n, and we have to find a 3*3 matrix which can be formed with combination of 0 or n and has maximum determinants.ExampleIf n = 15 then we can create matrix as follows −{{15, 15, 0}{0, 15, 15}{15, 0, 0}}For any 3*3 matrix having elements either 0 or n, the maximum possible determinant is 2 *(n)3. Hence answer is −2 * (15)3 = 6750AlgorithmFor any 3*3 matrix having elements either 0 or n, the maximum possible determinant is 2 *(n)3ExampleLet us now see an example − Live Demo#include using namespace std; int getMaxDeterminant(int ... Read More

Maximum Bitwise AND Pair from Given Range in C++

Narendra Kumar
Updated on 31-Dec-2019 12:19:58

150 Views

Problem statementGiven a range [L, R], the task is to find a pair (X, Y) such that L ≤ X < Y ≤ R and X & Y is maximum among all the possible pairs then print the bitwise AND of the found pair.ExampleIf L = 1 and R = 10 then maximum bitwise AND value is 8 which can be formed as follows −1000 # Binary representation of 8 Bitwise AND 1001 # Binary representation of 9 ---- 1000 # Final resultAlgorithmIterate from L to R and check the bitwise AND for every possible pair and print the maximum ... Read More

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