When we install MySQL server, a database named MySQL created automatically. This MySQL database contains five main grant tables with the help of which MySQL server can control the privileges of MySQL database server. These tables are as follows −user tableThis table contains user account and global privileges columns. MySQL uses the user table to either accept or reject a connection from a host. A privilege granted in the user table is effective to all databases on the MySQL server.db tableThis table contains database-level privileges. MySQL uses the db table to determine which database a user can access and from which host. ... Read More

To make it understand, we are using the following data from a table named ‘customerdetail’.mysql> Select * from Customerdetail; +----------------------+----------------------+-----------+---------------------+ | Name                 | FName                | Address   | Emailid             | +----------------------+----------------------+-----------+---------------------+ | Advik Jhamb          | Lovkesh Jhamb        | Mumbai    | Advik@gmail.com     | | Chirag Jai Patil     | Raman Jai Patil      | Gujrat    | chirahp@yahoo.com   | | Devansh Singh Rajput | Kishore Singh Rajput ... Read More

MySQL implements a sophisticated access control and privilege system that allows us to create comprehensive access rules for handling client operations and effectively preventing unauthorized clients from accessing the database system.The MySQL access control has two stages when a client connects to the server −Connection verification A client, which connects to the MySQL database server, needs to have a valid username and password. In addition, the host from that the client connects needs to match with the host within the MySQL grant table.Request verificationonce a connection is established successfully, for each statement issued by the client, MySQL checks whether the client ... Read More

We can also use ALTER USER statement along with IDENTIFIED BY clause to change MySQL user password. Its syntax would be as possible −SyntaxALTER USER user_name@host_name IDENTIFIED BY ‘new_password’Here, New_password would be new password we want to set for MySQL userUser_name is the name of a current user.Host_name is the name of the host of a current user.ExampleSuppose if we want to change the password user@localhost to ‘tutorials’ then it can be done as follows −ALTER USER user@localhost IDENTIFIED BY ‘tutorials’

We can use SET PASSWORD statement to change the password. Before using this command, we need to have at least UPDATE privileges. Its syntax would be as follows −SyntaxSET PASSWORD FOR ‘user_name@host_name’=new_password;Here, New_password would be new password we want to set for MySQL userUser_name is the name of the current user.Host_name is the name of the host of the current user.ExampleSuppose if we want to change the password user@localhost to ‘tutorials’ then it can be done as follows −SET PASSWORD FOR ‘user@localhost’= tutorials;

We need to use nested SUBSTRING_INDEX() function for getting the substring as output which is between two same delimiters in a string. For example, from the string ‘www.tutorialspoint.com’, we want the substring ‘tutorialspoint’, which is in between two same delimiters ‘.’ as output then SUBSTRING_INDEX() function can be used in nested form as follows −mysql> Select SUBSTRING_INDEX(SUBSTRING_INDEX('www.tutorialspoint.com','.',2),'.',-1)AS 'Nested SUBSTRING_INDEX'; +------------------------+ | Nested SUBSTRING_INDEX | +------------------------+ | tutorialspoint         | +------------------------+ 1 row in set (0.02 sec)

Suppose we have a table named ‘ipaddress’ which contains the IP addresses as its values in column ‘IP’ as follows −mysql> Select * from ipaddress; +-----------------+ | ip              | +-----------------+ | 192.128.0.5     | | 255.255.255.255 | | 192.0.255.255   | | 192.0.1.5       | +-----------------+ 4 rows in set (0.10 sec)Now with the help of SUBSTRING_INDEX() function in the following query, we can divide the IP address in four octets −mysql> Select IP, SUBSTRING_INDEX(ip, '.', 1)AS '1st Part',     -> SUBSTRING_INDEX(SUBSTRING_INDEX(ip, '.', 2), '.', -1)AS '2nd Part',     ... Read More

MySQL SUBSTRING_INDEX() function can accept the negative value of argument ‘count’ and in this case, it returns the substring from the right of the final delimiter.Examplemysql> Select SUBSTRING_INDEX('www.google.com','.',-2); +------------------------------------------+ | SUBSTRING_INDEX('www.google.com','.',-2) | +------------------------------------------+ | google.com                               | +------------------------------------------+ 1 row in set (0.00 sec) mysql> Select SUBSTRING_INDEX('www.google.com','.',-1); +------------------------------------------+ | SUBSTRING_INDEX('www.google.com','.',-1) | +------------------------------------------+ | com                                      | +------------------------------------------+ 1 row in set (0.00 sec)

Actually, we need to perform flush-privileges operation to tell the server to reload the grant tables. This can be done by issuing FLUSH PRIVILEGES statement or by executing a mysqladmin flush-privileges or mysqladmin reload command. FLUSH PRIVILEGES is really needed if we modify the grant tables directly using such as INSERT, UPDATE or DELETE, the changes have no effect on privileges checking until we either restart the server or tell it to reload the tables. But, Privileges assigned through GRANT choice don't want FLUSH PRIVILEGES to take effect - MySQL server cannotice these changes and reload the grant tables instantly. ... Read More

To change MySQL user password with the help of UPDATE statement, we need to update the ‘user’ table of the ‘mysql’ database. Its syntax would be as follows −SyntaxUSE mysql; UPDATE user SET authentication_string = PASSWORD(‘new_password’) WHERE user = user_name AND host = host_name;The first two statements will be common because to change the password for MySQL user we need to use MySQL database and update the user table.New_password would be new password we want to set for MySQL userUser_name is the name of the current user.Host_name is the name of the host of the current user.ExampleSuppose if we want ... Read More