PHP从MySQL表中选择数据'；一行

完整的PHP代码：

<?php
        $servername = "localhost";
        $username = "*****";
        $password = "**********";
        $dbname = "x1_1";

        // Create connection
        $conn = mysqli_connect($servername, $username, $password, $dbname);

        // Check connection
        if (!$conn) {
                die("Connection failed: " . mysqli_connect_error());
        }
        // Print out to console success
        echo '<script>console.log("Connected successfully! ")</script>';

        // sql to create table
        $sql = "CREATE TABLE MyGuests (
            id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY, 
            firstname VARCHAR(30) NOT NULL,
            lastname VARCHAR(30) NOT NULL,
            email VARCHAR(50),
            reg_date TIMESTAMP
        )";

        // Check if table was created
        if ($conn->query($sql) === TRUE) {
            // Was created
                echo '<script>console.log("Table MyGuests created successfully! ")</script>';
        } else {
            // Was not created
                echo '<script>console.log("Error creating table: ' . $conn->error . '")</script>';
        }

        // Insert data into table
        $sql = "INSERT INTO MyGuests (firstname, lastname, email)
        VALUES ('John', 'Doe', 'john@example.com');";

        $sql .= "INSERT INTO MyGuests (firstname, lastname, email)
        VALUES ('Mary', 'Moe', 'mary@example.com');";

        $sql .= "INSERT INTO MyGuests (firstname, lastname, email)
        VALUES ('Julie', 'Dooley', 'julie@example.com')";

        // Check if values were inserted successfully
        if ($conn->multi_query($sql) === TRUE) {
            // Inserted successfully
                echo '<script>console.log("New records created successfully! ")</script>';
        } else {
            // Was not inserted successfully
                echo '<script>console.log("Error: '. $sql .' "<br>" ' . $conn->error . '")</script>';
        }

        // Selects [ID, Firstname, and Lastname] from table
        $sql = "SELECT id, firstname, lastname FROM MyGuests";
        $result = $conn->query($sql);

        // If the number of rows is greater than zero print the data in the row. Else print zero results
        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();
    ?>

        // Selects [ID, Firstname, and Lastname] from table
        $sql = "SELECT id, firstname, lastname FROM MyGuests";
        $result = $conn->query($sql);

        // If the number of rows is greater than zero print the data in the row. Else print zero results
        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";
        }

---

在if条件中的
num_rows
之后添加导致内部服务器错误的
（$result->num_rows（）>0）
。num_rows是属性，不是方法，所以不是（）。在
if（$result
…行之前添加一行，以回显$result->num_行的值。表示了解的语句。甚至不安全！@sloather echo'console.log（“$result->num_行”）；在if条件下返回内部错误Add
（）
在
num_行之后作为
if（$result->num_行（）>0）
导致内部服务器错误。num_rows是一个属性，不是一个方法，所以不是（）。在
if（$result
…行）前面添加一行，以回显$result->num_rows的值。表示了解的语句。甚至不安全！@sloatherasher echo'console.log（“$result->num rows”）；返回内部错误