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)
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
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
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
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
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
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
Yes, we can remove a primary key using the DROP in MySQL. Following is the syntax −alter table yourTableName drop primary key;Let us first create a table −mysql> create table DemoTable ( UserId int NOT NULL PRIMARY KEY ); Query OK, 0 rows affected (0.58 sec)Following is the query to check the description of table −mysql> desc DemoTable;This will produce the following output displaying the Primary Key −+--------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+---------+------+-----+---------+-------+ | UserId | int(11) | NO | PRI ... Read More
Given an array of size 2X2 and the challenge is to print the sum of all the corner elements stored in an array.Assume a matrix mat[r][c], with some row “r” and column “c” starting row and column from 0, then its corner elements will be; mat[0][0], mat[0][c-1], mat[r-1][0], mat[r-1][c-1]. Now the task is to get these corner elements and sum those corner elements i.e., mat[0][0] + mat[0][c-1] + mat[r-1][0] + mat[r-1][c-1], and print the result on the screen.ExampleInput: Enter the matrix elements : 10 2 10 2 3 4 10 4 10 Output: sum of matrix is ... Read More
Given four variables a, b, c, d with predefined values that will print the given bracket depending upon the variable used.Where variable, a for (( b for () c for )( d for ))The task is to use all the given brackets and print the balanced bracket expression, if we cannot form a balanced bracket expression then print -1. In case of multiple answers we can print any of the multiple answers which can be formed using the given brackets.ExampleInput: a = 3, b = 2, c = 4, d = 3 Output : (((((()()()()())))))()()To achieve this result we can, ... Read More
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