MySQL - Suay.Site

How to cache MySQL / MariaDB query results

Posted by Alex On May 27, 2025

Contents 0. In MySQL, query caching has been completely removed in recent versions, while in MariaDB, on the contrary, it has become enabled by default. 1. How MySQL / MariaDB query caching works 2. When to use MySQL / MariaDB query caching 3. How to enable and configure MySQL / MariaDB query result caching 4. How to check MySQL /...

Should I close MySQL connections with $mysqli->close() in PHP scripts. Should I use $result->free()

Posted by Alex On April 17, 2025

Contents What are $mysqli->close() and $result->free() used for in PHP Is it necessary to close connections to MySQL / MariaDB and clear the result of the SQL query? When using $mysqli->close() and $result->free() will NOT give tangible results When to use $mysqli->close() and $result->free() Is it possible to close the MySQL database connection before completing the processing of query results...

How to list all current connections to MySQL and MariaDB databases

Posted by Alex On April 15, 2025

Contents List of running operations and processes on MySQL and MariaDB server How to view MySQL and MariaDB processes in real time What do the fields in the SHOW PROCESSLIST output mean How to display MySQL and MariaDB process data row by row instead of in a table Alternative syntax for SHOW FULL PROCESSLIST How to display only certain columns...

PHP Fatal error: Uncaught mysqli_sql_exception: Too many connections in (SOLVED)

Posted by Alex On April 10, 2025

Contents Error “Uncaught mysqli_sql_exception: Too many connections” Why does the “Too many connections” error occur How to temporarily increase the maximum number of connections to MySQL / MariaDB How to permanently increase the maximum number of connections to MySQL / MariaDB What is the maximum number of connections that can be established for MySQL and MariaDB 1. Error “Uncaught mysqli_sql_exception:...

How to transfer a database between DBMS servers without creating a database dump file (MySQL and MariaDB)

Posted by Alex On April 7, 2025

Contents Is it possible to transfer a database from one MySQL / MariaDB server to another without creating an intermediate file How to transfer a database from one server to another How to transfer a database from one MySQL/MariaDB instance to another when both MySQL/MariaDB instances are running on the same machine How to transfer a database from one MySQL/MariaDB...

How to run multiple MySQL/MariaDB server instances on one machine

Posted by Alex On April 3, 2025

Contents 1. Why you might want to run multiple MySQL or MariaDB servers on one computer 2. What you need to run multiple MySQL or MariaDB servers on one computer 3. Differences between MySQL and MariaDB when starting a second DBMS instance 4. Correcting the mariadb@.service file 5. How to configure a second MySQL or MariaDB instance 5.1 How to...

What do dots mean in MySQL and MariaDB SQL queries. How to refer from a table to a column in another table

Posted by Alex On March 1, 2025

Contents What do dots mean in MySQL and MariaDB SQL queries Identifier qualifiers in MySQL and MariaDB When to qualify a column name and when not to “ERROR 1046 (3D000): No database selected” / “#1046 - No database selected” even if qualified column names are used Conclusion Sources What do dots mean in MySQL and MariaDB SQL queries Consider the...

Choose UPDATE mysql.user SET or ALTER USER? (SOLVED)

Posted by Alex On September 29, 2024

Each MySQL and MariaDB user can have various settings, such as permission (grants) to execute certain queries to all or specific databases. Users also have settings related to identification (login) on the DBMS server, such as: user password, used authentication plugin. To change user settings such as password and authentication plugin, you can choose one of the following commands: UPDATE...

How to check what MySQL/MariaDB users exist and their characteristics

Posted by Alex On September 29, 2024

Contents How to display the names of all MySQL/MariaDB users How to display the names of all users and their hosts in MySQL/MariaDB How to check which users are allowed to log in without a password in MySQL/MariaDB How to check which users have expired passwords in MySQL/MariaDB. How to list users with expired passwords How to check which plugin...

How to display only column names and nothing more for a table in MySQL and MariaDB

Posted by Alex On September 29, 2024

How to display only field names in SHOW COLUMNS Let's look at a situation when in MySQL and MariaDB you need to get information not from the table, but about the table itself, for example, field names. We have already looked at how to get a list of fields for any table; for this, an SQL query with the SHOW...