Advertisement:
Read Later
What is MySQL?(1)
MySQL, pronounced either "My S-Q-L" or "My Sequel," is an open source relational database management system. It is based on the structured query language (SQL), which is used for adding, removing, and modifying information in the database. Standard SQL commands, such as ADD, DROP, INSERT, and UPDATE can be used with MySQL.
MySQL can be used for a variety of applications but is most commonly found on Web servers. A website that uses MySQL may include Web pages that access information from a database. These pages are often referred to as "dynamic," meaning the content of each page is generated from a database as the page loads. Websites that use dynamic Web pages are often referred to as database-driven websites.
Many database-driven websites that use MySQL also use a Web scripting language like PHP to access information from the database. MySQL commands can be incorporated into the PHP code, allowing part or all of a Web page to be generated from database information. Because MySQL and PHP are both open source (meaning they are free to download and use), the PHP/MySQL combination has become a popular choice for database-driven websites.
Why is MySQLi popular as a PHP extension?
MySQLi is an extension for PHP that allows you(the browser) to access and change data stored on MySQL database servers, providing a simple syntax for PHP developers as compared to other extensions. In that regard, the applications which use the combination of PHP and MySQL via MySQLi has proliferated.
| Function | Description |
|---|---|
| mysqli_affected_rows() | Returns the number of affected rows in the previous MySQL operation |
| mysqli_autocommit() | Turns on or off auto-committing database modifications |
| mysqli_change_user() | Changes the user of the specified database connection |
| mysqli_character_set_name() | Returns the default character set for the database connection |
| mysqli_close() | Closes a previously opened database connection |
| mysqli_commit() | Commits the current transaction |
| mysqli_connect_errno() | Returns the error code from the last connection error |
| mysqli_connect_error() | Returns the error description from the last connection error |
| mysqli_connect() | Opens a new connection to the MySQL server |
| mysqli_data_seek() | Adjusts the result pointer to an arbitrary row in the result-set |
| mysqli_debug() | Performs debugging operations |
| mysqli_dump_debug_info() | Dumps debugging info into the log |
| mysqli_errno() | Returns the last error code for the most recent function call |
| mysqli_error_list() | Returns a list of errors for the most recent function call |
| mysqli_error() | Returns the last error description for the most recent function call |
| mysqli_fetch_all() | Fetches all result rows as an associative array, a numeric array, or both |
| mysqli_fetch_array() | Fetches a result row as an associative, a numeric array, or both |
| mysqli_fetch_assoc() | Fetches a result row as an associative array |
| mysqli_fetch_field_direct() | Returns meta-data for a single field in the result set, as an object |
| mysqli_fetch_field() | Returns the next field in the result set, as an object |
| mysqli_fetch_fields() | Returns an array of objects that represent the fields in a result set |
| mysqli_fetch_lengths() | Returns the lengths of the columns of the current row in the result set |
| mysqli_fetch_object() | Returns the current row of a result set, as an object |
| mysqli_fetch_row() | Fetches one row from a result-set and returns it as an enumerated array |
| mysqli_field_count() | Returns the number of columns for the most recent query |
| mysqli_field_seek() | Sets the field cursor to the given field offset |
| mysqli_field_tell() | Returns the position of the field cursor |
| mysqli_free_result() | Frees the memory associated with a result |
| mysqli_get_charset() | Returns a character set object |
| mysqli_get_client_info() | Returns the MySQL client library version |
| mysqli_get_client_stats() | Returns statistics about client per-process |
| mysqli_get_client_version() | Returns the MySQL client library version as an integer |
| mysqli_get_connection_stats() | Returns statistics about the client connection |
| mysqli_get_host_info() | Returns the MySQL server hostname and the connection type |
| mysqli_get_proto_info() | Returns the MySQL protocol version |
| mysqli_get_server_info() | Returns the MySQL server version |
| >mysqli_get_server_version() | Returns the MySQL server version as an integer |
| mysqli_info() | Returns information about the most recently executed query |
| mysqli_init() | Initializes MySQLi and returns a resource for use with mysqli_real_connect() |
| mysqli_insert_id() | Returns the auto-generated id used in the last query |
| mysqli_kill() | Asks the server to kill a MySQL thread |
| mysqli_more_results() | Checks if there are more results from a multi query |
| >mysqli_multi_query() | Performs one or more queries on the database |
| mysqli_next_result() | Prepares the next result set from mysqli_multi_query() |
| mysqli_num_fields() | Returns the number of fields in a result set |
| mysqli_num_rows() | Returns the number of rows in a result set |
| mysqli_options() | Sets extra connect options and affect behavior for a connection |
| mysqli_ping() | Pings a server connection, or tries to reconnect if the connection has gone down |
| mysqli_prepare() | Prepares an SQL statement for execution |
| mysqli_query() | Performs a query against the database |
| mysqli_real_connect() | Opens a new connection to the MySQL server |
| mysqli_real_escape_string() | Escapes special characters in a string for use in an SQL statement |
| mysqli_real_query() | Executes an SQL query |
| mysqli_reap_async_query() | Returns the result from async query |
| mysqli_refresh() | Refreshes tables or caches, or resets the replication server information |
| mysqli_rollback() | Rolls back the current transaction for the database |
| >mysqli_select_db() | Changes the default database for the connection |
| mysqli_set_charset() | Sets the default client character set |
| mysqli_set_local_infile_default() | Unsets user defined handler for load local infile command |
| mysqli_set_local_infile_handler() | Set callback function for LOAD DATA LOCAL INFILE command |
| mysqli_sqlstate() | Returns the SQLSTATE error code for the last MySQL operation |
| mysqli_ssl_set() | Used to establish secure connections using SSL |
| mysqli_stat() | Returns the current system status |
| mysqli_stmt_init() | Initializes a statement and returns an object for use with mysqli_stmt_prepare() |
| mysqli_store_result() | Transfers a result set from the last query |
| mysqli_thread_id() | Returns the thread ID for the current connection |
| mysqli_thread_safe() | Returns whether the client library is compiled as thread-safe |
| mysqli_use_result() | Initiates the retrieval of a result set from the last query executed using the mysqli_real_query() |
| mysqli_warning_count() | Returns the number of warnings from the last query in the connection |
(1) Christensson, Per. "MySQL Definition." TechTerms. Sharpened Productions, 06 March 2007. Web. 22 February 2019. <https://techterms.com/definition/mysql>.
(2) https://www.w3schools.com/php/php_ref_mysqli.asp