mysqli::query

mysqli_query

(PHP 5, PHP 7, PHP 8)

mysqli::query -- mysqli_query — Performs a query on the database

Опис

Об'єктно-орієнтований стиль

public mysqli::query(string $query, int $result_mode = MYSQLI_STORE_RESULT): mysqli_result|bool

Процедурний стиль

mysqli_query(mysqli $mysql, string $query, int $result_mode = MYSQLI_STORE_RESULT): mysqli_result|bool

Performs a query against the database.

Увага

Попередження з безпеки: SQL-ін'єкція

Якщо рядок запиту має містити введені користувачем значення, то потрібно виконати підготовлений запит. Або ж дані мають бути правильно відформатовані, а всі рядки — екрановані функцією mysqli_real_escape_string().

For non-DML queries (not INSERT, UPDATE or DELETE), this function is similar to calling mysqli_real_query() followed by either mysqli_use_result() or mysqli_store_result().

Зауваження:
In the case where a statement is passed to mysqli_query() that is longer than max_allowed_packet of the server, the returned error codes are different depending on whether you are using MySQL Native Driver (mysqlnd) or MySQL Client Library (libmysqlclient). The behavior is as follows:

mysqlnd on Linux returns an error code of 1153. The error message means got a packet bigger than max_allowed_packet bytes.

mysqlnd on Windows returns an error code 2006. This error message means server has gone away.

libmysqlclient on all platforms returns an error code 2006. This error message means server has gone away.

Параметри

mysql

Тільки процедурний стиль: об'єкт mysqli, якого повертає функція mysqli_connect() або mysqli_init()

query

The query string.

result_mode

The result mode can be one of 3 constants indicating how the result will be returned from the MySQL server.

MYSQLI_STORE_RESULT (default) - returns a mysqli_result object with buffered result set.

MYSQLI_USE_RESULT - returns a mysqli_result object with unbuffered result set. As long as there are pending records waiting to be fetched, the connection line will be busy and all subsequent calls will return error Commands out of sync. To avoid the error all records must be fetched from the server or the result set must be discarded by calling mysqli_free_result().

MYSQLI_ASYNC (available with mysqlnd) - the query is performed asynchronously and no result set is immediately returned. mysqli_poll() is then used to get results from such queries. Used in combination with either MYSQLI_STORE_RESULT or MYSQLI_USE_RESULT constant.

Значення, що повертаються

Returns false on failure. For successful queries which produce a result set, such as SELECT, SHOW, DESCRIBE or EXPLAIN, mysqli_query() will return a mysqli_result object. For other successful queries, mysqli_query() will return true.

Помилки/виключення

Якщо увімкнені звіти про помилки mysqli (MYSQLI_REPORT_ERROR) і запитана операція не виконалась, буде виведено попередження, але якщо встановлено режим MYSQLI_REPORT_STRICT, буде викинуто виключення mysqli_sql_exception.

Приклади

Приклад #1 mysqli::query() example

Об'єктно-орієнтований стиль

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* Create table doesn't return a resultset */
$mysqli->query("CREATE TEMPORARY TABLE myCity LIKE City");
printf("Table myCity successfully created.\n");

/* Select queries return a resultset */
$result = $mysqli->query("SELECT Name FROM City LIMIT 10");
printf("Select returned %d rows.\n", $result->num_rows);

/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
$result = $mysqli->query("SELECT * FROM City", MYSQLI_USE_RESULT);

/* Note, that we can't execute any functions which interact with the
    server until all records have been fully retrieved or the result
    set was closed. All calls will return an 'out of sync' error */
$mysqli->query("SET @a:='this will not work'");

Процедурний стиль

<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

/* Create table doesn't return a resultset */
mysqli_query($link, "CREATE TEMPORARY TABLE myCity LIKE City");
printf("Table myCity successfully created.\n");

/* Select queries return a resultset */
$result = mysqli_query($link, "SELECT Name FROM City LIMIT 10");
printf("Select returned %d rows.\n", mysqli_num_rows($result));

/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
$result = mysqli_query($link, "SELECT * FROM City", MYSQLI_USE_RESULT);

/* Note, that we can't execute any functions which interact with the
    server until all records have been fully retrieved or the result
    set was closed. All calls will return an 'out of sync' error */
mysqli_query($link, "SET @a:='this will not work'");

Подані вище приклади виведуть щось схоже на:

Table myCity successfully created.
Select returned 10 rows.

Fatal error: Uncaught mysqli_sql_exception: Commands out of sync; you can't run this command now in...

Прогляньте також

mysqli_execute_query() - Prepares, binds parameters, and executes SQL statement
mysqli_real_query() - Execute an SQL query
mysqli_multi_query() - Performs one or more queries on the database
mysqli_prepare() - Prepares an SQL statement for execution
mysqli_free_result() - Frees the memory associated with a result