MySQL is a popular free and open source relational database management system that is widely used in a variety of applications, including websites and mobile applications. Websites and applications that use MySQL databases often require users to provide a username and password when registering or logging in. These passwords are stored in encrypted form in the database to ensure security. However, sometimes it is necessary to query the password through MySQL to implement certain functions, such as resetting the password or verifying the password.
This article will introduce you how to query passwords in MySQL, mainly including the following aspects:
MySQL password scatter Column Algorithm
In MySQL, passwords are not stored in clear text in the database, but are stored after being processed by a password hashing algorithm. Password hashing algorithms convert passwords into another form, called a password hash value. When the user enters a password, MySQL will hash the password entered by the user and compare it with the hash value stored in the database to verify the correctness of the password.
MySQL supports multiple hashing algorithms, including MD5, SHA-1, SHA-2, etc. The password hashing algorithm can be specified when the user is created or modified at runtime. The following are commonly used password hashing algorithms in MySQL:
Basic syntax for querying MySQL user password
The most basic way to query MySQL user password is to use the SELECT statement and the PASSWORD function. The PASSWORD function is a built-in function of MySQL that converts raw passwords into hash values.
The following is the basic syntax for querying the MySQL user password:
SELECT PASSWORD('password');Among them, password is the password you want to query. For example, if you want to query the hash value of the password "123456", you can use the following statement:
SELECT PASSWORD('123456');After executing this statement, MySQL will return a hash value starting with "", such as " 6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9".
Advanced syntax for querying MySQL user passwords
In addition to using the PASSWORD function, MySQL also provides other functions and statements to more conveniently query user passwords.
Before MySQL was updated to 5.7.5, the hash value created using the PASSWORD function used an insecure hashing algorithm and has been Declared unsafe. For backward compatibility, MySQL provides the OLD_PASSWORD function for creating hash values using older hashing algorithms.
The following is the syntax for querying passwords using the OLD_PASSWORD function:
SELECT OLD_PASSWORD('password');The HEX function is used to convert a binary string to hexadecimal hexadecimal string. Hash values stored in MySQL are binary strings, so they can be converted to hexadecimal strings using the HEX function.
The following is the syntax for querying passwords using the HEX function:
SELECT HEX(PASSWORD('password'));In MySQL, user passwords are usually Stored in the password field in the users table. Therefore, you can use a SELECT statement to query the password field in the users table to get the password value of the corresponding user.
The following is the syntax for querying the value of the password field in the user table:
SELECT password FROM user WHERE username='username';
where user is the name of your user table, and username is the username for which the password is to be queried. After executing this statement, MySQL will return the user's password field value.
How to use password query results
Once you know how to query a MySQL user password, you can use the query results to perform a variety of operations. For example, you can use query results to reset a user's password, verify a user's password, or perform other functions that require a password.
If you need to reset the user password, you can use the query results as part of the UPDATE statement to store the new password hash value in the database .
The following is an example of using the query results to reset a user's password:
UPDATE user SET password=PASSWORD('new_password') WHERE username='username';where user is your user table name, username is the username to reset the password, and new_password is the new password in clear text . Use this statement to store the hash of the new password in the database.
If you need to verify a user password, you can compare the query results with the password entered by the user. If the comparison results match, the user password is correct.
The following is an example of using the query results to verify the user password:
SELECT password FROM user WHERE username='username';
After executing this statement, the hash value of the user password will be queried. Convert the user entered password into a hash value using the same hashing algorithm and compare it with the query results. If the comparison results match, the user password is correct.
How to Protect MySQL User Passwords
MySQL user passwords are a critical component in protecting your applications and data. To protect these passwords, here are some suggestions:
Conclusion
Querying MySQL user passwords is an important part of managing and protecting MySQL databases. This article introduces the hashing algorithm, basic query syntax, advanced query syntax and how to protect user passwords. Knowing this knowledge will be very helpful if you need to manage MySQL databases or develop MySQL-based applications. Please remember that any operations related to user passwords should be done with caution to ensure the security of user passwords.
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