Question

这是我用于连接数据库并查询表＆＃34; userActivityTime＆＃34;的php，其中有一行。我没有连接到数据库的麻烦（即没有错误），但我的查询不起作用，尽管在互联网上看，我无法弄清楚为什么。希望你们都能提供帮助。非常感谢提前！

<?php

// ESTABLISH TABLE AND COLUMN NAMES

$mysqli = new mysqli("*****", "****", "*****", "****");

// MAKE SURE CONNECTION SUCCEEDED

if ($mysqli_connection->connect_error) {
    echo "Not connected, error: " . $mysqli_connection->connect_error;
    exit();
} else {
    echo "connected";
}

$query = "SELECT 'userDailyTime' FROM 'userActivityTime'";
if ($mysqli->query($query)) {
    echo $mysqli->error;
}


exit();

?>

Answer 1

如果需要，请使用反向标记而不是单引号：

SELECT `userDailyTime` FROM `userActivityTime`

或只是

SELECT userDailyTime FROM userActivityTime

修改

来自互联网的一个例子，将你的东西塞进概念中。

<?php $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "myDB"; // Create connection $conn = new mysqli($servername, $username, $password, $dbname); // Check connection if ($conn->connect_error) { die("Connection failed: " . $conn->connect_error); } $sql = "SELECT id, firstname, lastname FROM MyGuests"; $result = $conn->query($sql); if ($result->num_rows > 0) { // output data of each row while($row = $result->fetch_assoc()) { echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>"; } } else { echo "0 results"; } $conn->close(); ?>

Answer 2

您不需要将表名和列名放在引号中。您告诉它在查询成功时回显$mysqli->error（前面带有感叹号）。另外，您创建了$mysqli，然后将其称为$mysqli_connection，因此我不确定您的代码是如何工作的。

Answer 3

试试这个：

<?php

// ESTABLISH TABLE AND COLUMN NAMES

$mysqli = new mysqli("*****", "****", "*****", "****");

// MAKE SURE CONNECTION SUCCEEDED

if ($mysqli->connect_errno) {
    echo "Not connected, error: " . $mysqli->connect_error;
    return false;
} else {
    echo "connected";
}

$query = "SELECT userDailyTime FROM userActivityTime";
if (!$mysqli->query($query)) {
    echo $mysqli->error;
}
return true;

?>

mysqli SELECT查询无法正常工作，原因不明

3 个答案: