PHP mysqli query() 函数

示例 - 面向对象风格

对数据库执行查询：

<?php
$mysqli = new mysqli("localhost","my_user","my_password","my_db");

// Check connection
if ($mysqli -> connect_errno) {
echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
exit();
}

// Perform query
if ($result = $mysqli -> query("SELECT * FROM Persons")) {
echo "Returned rows are: " . $result -> num_rows;
// Free result set
$result -> free_result();
}

$mysqli -> close();
?>

查看底部的程序样式示例。

定义和用法

query() / mysqli_query() 函数对数据库执行查询。

语法

面向对象风格：

$mysqli -> query( query, resultmode)

程序风格：

mysqli_query( connection, query, resultmode)

参数值

Parameter	Description
connection	Required. Specifies the MySQL connection to use
query	Required. Specifies the SQL query string
resultmode	Optional. A constant. Can be one of the following: MYSQLI_USE_RESULT (Use this to retrieve large amount of data) MYSQLI_STORE_RESULT (This is default)

Parameter

Description

connection

Required. Specifies the MySQL connection to use

query

Required. Specifies the SQL query string

resultmode

Optional. A constant. Can be one of the following:

MYSQLI_USE_RESULT (Use this to retrieve large amount of data)
MYSQLI_STORE_RESULT (This is default)

技术细节

返回值：	对于成功的 SELECT、SHOW、DESCRIBE 或 EXPLAIN 查询，它将返回 mysqli_result 对象。对于其他成功的查询，它将返回 TRUE。失败时为 FALSE
PHP 版本：	5+
PHP 变更日志：	PHP 5.3.0 添加了异步查询的能力

示例 - 程序风格

对数据库执行查询：

<?php
$con = mysqli_connect("localhost","my_user","my_password","my_db");

if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}

// Perform query
if ($result = mysqli_query($con, "SELECT * FROM Persons")) {
echo "Returned rows are: " . mysqli_num_rows($result);
// Free result set
mysqli_free_result($result);
}

mysqli_close($con);
?>

❮ PHP MySQLi 参考