PHP’s mysqli extension is encapsulated into a class. It is an object-oriented technology and has faster execution speed. It is more convenient and efficient than the traditional procedural method.
By default, mysqli in PHP is If it is not opened, we need to
To use the mysqli extension in PHP, you need to add the following settings to the configuration file php.ini:
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extension=php_mysqli.dll
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If the above settings are already in the configuration file, make sure there is no ";" in front of the extension, otherwise remove it. Let’s start by introducing how to use the mysqli extension to access the database. That’s it.
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$db_host="localhost"; //连接的服务器地址 $db_user="root"; //连接数据库的用户名 $db_psw="root"; //连接数据库的密码 $db_name="sunyang"; //连接的数据库名称 $mysqli=new mysqli(); $mysqli->connect($db_host,$db_user,$db_psw,$db_name); ?> |
$db_user="root"; //Username to connect to the database
$db_psw="root"; //Password to connect to the database
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$connection = mysqli_connect("localhost","root","root","sunyang"); |
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$connection = mysqli_connect("localhost","root","root","sunyang");<🎜> if ( $connection ) {<🎜> echo "Database connection successful";<🎜> }else {<🎜> echo "Database connection failed";<🎜> }<🎜> ?> |
Data query
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$query="select * from employee"; $result=$mysqli->query($query); if ($result) { ; echo ($row[0])." "; echo ($row[1])." "; echo ($row[2])." "; echo ($row[3])." "; echo " "; } } }else { echo "Query failed"; } $result->free(); $mysqli->close(); ?> |
Others like data saving and waiting
Member methods in mysqli class
__construct(): Construction method, used to create a mysqli object and also establish a connection.
autocommit(): Turn on or off automatic submission of database modifications.
change_user(): Change the user specified for the database connection.
character_set_name(): Returns the default character set for database connection.
close(): Close the previously opened connection.
commit(): Submit the current transaction.
connect(): Open a new connection to the mysql database server.
debug(): Perform debugging operations.
dump_debug_info(): Dump debugging information.
get_client_info(): Returns the client version.
get_host_info(): Returns the connection type represented by a string, such as: Localhost via UNIX socket
get_server_info(): Returns the mysql server version.
get_server_version(): Returns the mysql server version in integer form.
init(): Initialize a mysqli and return a resource.
info(): Retrieve information about recently executed queries.
kill(): Kill a mysql thread.
multi_query(): Execute multiple query statements.
more_results(): Retrieve whether there are any more query results from a multi-query statement.
next_result(): Read the next result from the currently executed multi-query.
options(): Set options.
ping(): If there is no connection, ping a server to connect or reconnect.
prepare(): Prepare for the execution of a sql statement and return the mysqli_stmt object.
query(): All interactions with the database are performed through queries. This method sends a query to the database for execution. If the execution fails, it returns FALSE.
real_connect(): Try to open a connection to the mysql database server.
escape_string(): A string that escapes special characters.
rollback(): Rollback the current transaction.
select_db(): Select a default database for database queries.
set_charset(): Set the default client character set.
ssl_set(): Use ssl to establish a secure connection.
stat(): Get the current system status.
stmt_init(): Initialize a statement and return a mysql_stmt object.
store_result(): Transfer the result set from the last query.
thread_safe(): Whether to consider returning safe threads.
Member attributes in mysql class
$affected_rows: The number of rows affected in the previous mysql operation.
$client_info: mysql client version (string).
$client_version: mysql client version (integer).
$errno: The error code of the most recent function call.
$error: The error message string of the latest function call.
$field_count(): Query the number of columns obtained.
$host_info: connection type to use (string).
$info: Recently executed query.
$insert_id: The number automatically generated by the last query.
$protocol_version: The version used by the mysql protocol.
$sqlstate: Contains the last error of SQLSTATE error code.
$thread_id: Current connection thread ID.
$warning_count: The number of warnings generated during the execution of the previous sql statement.