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To get some last number of characters from the data stored in MySQL table’s column, we can use MySQL RIGHT() function. It will return the number of characters specified as it argument. We need to provide the name of the column, having the particular record from which we want to get last characters, as its first argument. To demonstrate it we are taking the example of a table named ‘examination_btech’ having the following examination details of students −mysql> Select * from examination_btech; +-----------+----------+--------+ | RollNo | Name | Course | +-----------+----------+--------+ | 201712001 | Rahul | ... Read More
We can see only the list of stored procedures in a particular MySQL database by the following query −mysql> SHOW PROCEDURE STATUS WHERE db = 'query'\G *************************** 1. row *************************** Db: query Name: allrecords Type: PROCEDURE Definer: root@localhost Modified: 2017-11-11 09:56:11 Created: 2017-11-11 09:56:11 Security_type: DEFINER Comment: character_set_client: cp850 collation_connection: cp850_general_ci Database Collation: latin1_swedish_ci 1 row in set (0.01 sec)
When we use MySQL COUNT() function to count the values stored in a column which also stored some NULL values then MySQL ignores the NULL and returns the result for only non-NULL values. To understand it, we are using the data, as follows, from table ‘Employee’ −mysql> Select * from Employee; +----+--------+--------+ | ID | Name | Salary | +----+--------+--------+ | 1 | Gaurav | 50000 | | 2 | Rahul | 20000 | | 3 | Advik | 25000 | | 4 | Aarav | 65000 | | 5 | Ram | 20000 | | 6 | ... Read More
With the help of SHOW TABLES command, we can get only the name having no other information about the tables. For example, we can see the list of tables in a database named tutorial as follows −mysql> show tables; +--------------------+ | Tables_in_tutorial | +--------------------+ | student | +--------------------+ 1 row in set (0.00 sec)
For calculating the sum of only dissimilar values of the column we can use ‘DISTINCT’ keyword along with the name of the column. To understand SUM() function for dissimilar values, consider an ‘employee_tbl’ table, which is having the following records −mysql> SELECT * FROM employee_tbl; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 2007-01-24 | 250 | | 2 | Ram | 2007-05-27 | 220 | | 3 | Jack | 2007-05-06 | 170 ... Read More
We can use FIELD() function to find the index position of a string stored as a record in MySQL table’s column. To demonstrate it we are using the table named ‘websites’ having the following dataExamplemysql> Select * from websites; +----+---------------+------------------------+ | Id | Purpose | Webaddress | +----+---------------+------------------------+ | 1 | For tutorials | www.tutorialspoint.com | | 2 | For searching | www.google.co.in | | 3 | For email | www.gmail.com | +----+---------------+------------------------+ 3 rows in set (0.00 sec)Now, suppose if we ... Read More
When MySQL SUM() function used with SELECT statement that returns no matching rows then there is nothing to evaluate and it returns NULL as output. Sometimes, we thought it must return 0 as output but 0 is a number itself and for no matching rows it not significant to return 0 hence it returns NULL. To understand the above concept, consider an ‘employee_tbl’ table, which is having the following records −mysql> SELECT * FROM employee_tbl; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 2007-01-24 | 250 ... Read More
When we use MySQL SUM() function with GROUP BY Clause the SUM() function evaluates the sum for every group specified in the GROUP BY clause. The benefit of using SUM() with GROUP BY clause is that we can easily find the total of a particular group. To understand the above concept, consider an ‘employee_tbl’ table, which is having the following records −mysql> SELECT * FROM employee_tbl; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 2007-01-24 | 250 | | 2 | Ram ... Read More
By using MySQL SUM() function with the HAVING clause, it filters the result based on a specific condition given after the HAVING clause. To understand the above concept, consider an ‘employee_tbl’ table, which is having the following records −mysql> SELECT * FROM employee_tbl; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 2007-01-24 | 250 | | 2 | Ram | 2007-05-27 | 220 | | 3 | Jack | 2007-05-06 | ... Read More
We must have the following prerequisites before starting writing and using MySQL stored procedures −MySQL VersionAs we know that MySQL 5 introduced stored procedures, hence first of all we need to check for the version of MySQL before staring writing and using stored procedures. It can be done with the following query −mysql> Select VERSION(); +-----------+ | VERSION() | +-----------+ | 5.7.20 | +-----------+ 1 row in set (0.10 sec)Privileges for the current userActually, CREATE PROCEDURE and CREATE FUNCTION require the CREATE ROUTINE privilege. By default, MySQL automatically grants the ALTER ROUTINE and EXECUTE privileges to the routine creator. ... Read More