Implement WHERE IN vs OR in MySQL with Example

AmitDiwan
Updated on 22-Aug-2019 07:05:48

155 Views

The IN uses an index while OR does not use an index in MySQL.Let us first create a table −mysql> create table DemoTable711 (    Id int,    Name varchar(100) ); Query OK, 0 rows affected (0.92 sec)Insert some records in the table using insert command −mysql> insert into DemoTable711 values(100, 'Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable711 values(101, 'Robert'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable711 values(102, 'Carol'); Query OK, 1 row affected (0.35 sec) mysql> insert into DemoTable711 values(103, 'Mike'); Query OK, 1 row affected (0.17 sec) mysql> insert ... Read More

Print Maximum Sum Square Sub-Matrix of Given Size in C

Sunidhi Bansal
Updated on 22-Aug-2019 07:04:58

642 Views

Given a matrix of NxN find a sub matrix of MxM where M=1 such that addition of all the elements of matrix MxM is maximum. Input of matrix NxN can contain zero, positive and negative integer values.ExampleInput:    {{1, 1, 1, 1, 1},    {2, 2, 2, 2, 2},    {3, 3, 3, 3, 3},    {4, 4, 4, 4, 4},    {5, 5, 5, 5, 5} } Output:    4 4    5 5The above problem can be solved by a simple solution in which we can take whole matrix NxN, then find out all possible MxM matrix and ... Read More

Fix MySQL Database Error HASH1064

AmitDiwan
Updated on 22-Aug-2019 07:02:02

2K+ Views

The Database Error #1064 may occur due to incorrect syntax. For example, let’s say we are creating the below table −mysql> create table DemoTable    (       UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY,       UserName varchar(100),       UserAge int,       UserAddress varchar(200),       UserCountryName varchar(100) ,       isMarried boolean,    );This will produce the following output i.e. error −ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' ... Read More

MySQL Stored Procedure Parameters with Special Characters

AmitDiwan
Updated on 22-Aug-2019 06:58:36

249 Views

You cannot give MySQL stored procedure parameter with @ in the beginning. You can give @ sign in user-defined variables.Following is the syntax −SET @yourVariableName=yourValue;Let us implement the above syntax to correctly place @sign −mysql> DELIMITER // mysql> CREATE PROCEDURE declare_Variable(IN StudentName varchar(100))    BEGIN       SET @Name=StudentName;       SELECT @Name;    END // Query OK, 0 rows affected (0.12 sec) mysql> DELIMITER ;Now you can call stored procedure with the help of CALL command −mysql> call declare_Variable('John Smith');This will produce the following output −+------------+ | @Name | +------------+ | John Smith | +------------+ 1 row in set (0.00 sec) Query OK, 0 rows affected, 1 warning (0.03 sec)

Insert or Update in the Same MySQL Query

AmitDiwan
Updated on 22-Aug-2019 06:56:16

209 Views

Yes, use ON DUPLICATE KEY UPDATE. Let us first create a table −mysql> create table DemoTable(Id int NOT NULL PRIMARY KEY, Number int); Query OK, 0 rows affected (0.83 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1, 190) ON DUPLICATE KEY UPDATE Number=Number+10; Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(2, 130) ON DUPLICATE KEY UPDATE Number=Number+10; Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(1, 190) ON DUPLICATE KEY UPDATE Number=Number+10; Query OK, 2 rows affected (0.14 sec) mysql> insert into DemoTable values(2, 130) ON DUPLICATE ... Read More

Print Left Rotation of Array in O(N) Time and O(1) Space in C

Sunidhi Bansal
Updated on 22-Aug-2019 06:54:19

186 Views

We are given an array of some size n and multiple integer values, we need to rotate an array from a given index k.We want to rotate an array from a index k like −ExamplesInput: arr[] = {1, 2, 3, 4, 5}    K1 = 1    K2 = 3    K3 = 6 Output:    2 3 4 5 1    4 5 1 2 3    2 3 4 5 1AlgorithmSTART Step 1 -> Declare function void leftRotate(int arr[], int n, int k)    Declare int cal = k% n    Loop For int i=0 and i In ... Read More

Print K Different Sorted Permutations of a Given Array in C

Sunidhi Bansal
Updated on 22-Aug-2019 06:49:37

215 Views

Given an array a[] containing N integers, the challenge is to print k different permutations of indices such that the values at those indices form a non-decreasing sequence. Print -1 if it is not possible.ExampleInput: arr[] = {2, 5, 6, 2, 2, 2, 2}, k = 4 Output:    0 3 4 5 6 1 2    3 0 4 5 6 1 2    0 3 4 5 6 1 2    3 0 4 5 6 1 2Sort the given array and keep track of the original indices of each element. That gives one required permutation. Now if ... Read More

Set NULL Values to 0 in MySQL Select

AmitDiwan
Updated on 22-Aug-2019 06:44:54

437 Views

For this, use IFNULL(). Let us first create a table −mysql> create table DemoTable (Value int); Query OK, 0 rows affected (1.02 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(NULL); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(NULL); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(30); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> ... Read More

Set Special Characters for Password in MySQL User Creation

AmitDiwan
Updated on 22-Aug-2019 06:40:42

462 Views

To set special characters for a password, use the following syntax −create user 'yourUserName'@'yourHostName' identified by 'yourSpecialCharacterPassword';Let us implement the above syntax in order to create a new user and set password with special characters −mysql> create user 'Mike'@'localhost' identified by 'Mike_123456'; Query OK, 0 rows affected (0.35 sec)Let us check the table where MySQL user and host is stored −mysql> select user, host from MySQL.user;This will produce the following output. The new user created successfully −+------------------+-----------+ | user             | host      | +------------------+-----------+ | Bob              | ... Read More

Print Index of Columns Sorted by Count of Zeroes in a Given Matrix in C

Sunidhi Bansal
Updated on 22-Aug-2019 06:38:22

157 Views

Given an array of size NxM where N number of rows and M number of columns, and the task is to print the number of zeroes in every column of a corresponding matrix after performing sort operation on the basis of number of zeros present in any column.For example if the 1st column contain 1 zeros and 2nd column doesn’t contain any number of zeros and 3rd column contain 2 zeroes then the result should be − 3 1 2.ExampleInput:    0 0 0    1 1 1    1 0 1 Output: 1 3 2ExplanationNote − the matrix is ... Read More

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