PHP：致命錯誤：調用未定義的方法mysqli

Question

好的，我上周問過一個問題。 我得到了一些答案，其中幾個沒有幫助; 但是，我決定重新檢查我的所有關系。 這確實解決了一些問題，因為我必須在這里檢查以使其正常運行。 接下來出於某種原因，我沒有檢查我的查詢，以確保它在mysql中工作。 我還注意到我的版本有一種方法可以將查詢輸出到PHP代碼中。 現在我遇到了錯誤代碼：

致命錯誤：調用未定義的方法mysqli :: SELECT tblConference.colConferenceName，tblSchool.colSchoolName，tblSchool.colClass，tblSurface.colSurfaceName，tblSurface.colSurfaceCompany，tblStadium.colStadiumName，tblStadium.colAddress，tblStadium.colCity，tblStadium.colRegion，tblStadium.colCounty ，tblStadium.colCapacity FROM tblStadium，tblConference，tblSurface，tblSchool，tblStadiumSchool WHERE tblConference.colConferenceID = tblSchool.colConferenceID AND tblSurface.colSurfaceID = tblStadium.colSurfaceID AND tblStadium.colStadiumID = tblStadiumSchool.colStadiumID AND tblSchool.colSchoolID = tblStadiumSchool.colSchoolID AND tblSchool.colSchoolName喜歡在第24行的C：\\ xampp \\ htdocs \\ stadium \\ alpha \\ a.php中的tblSchool.colSchoolName（）訂單

現在這是我的新代碼，我會嘗試讓它看起來中等，

    $mysqli = new mysqli("localhost", "root", "", "dbstadium");
    /* check connection */
      if (mysqli_connect_errno()) {
        printf("Connect failed: %s\n", mysqli_connect_error);
        exit();
        }
    /* your sql query */

$ sql =“SELECT tblConference.colConferenceName，tblSchool.colSchoolName，tblSchool.colClass，tblSurface.colSurfaceName，tblSurface.colSurfaceCompany，tblStadium.colStadiumName，tblStadium.colAddress，tblStadium.colCity，tblStadium.colRegion，tblStadium.colCounty，tblStadium.colCapacity FROM tblStadium ，tblConference，tblSurface，tblSchool，tblStadiumSchool WHERE tblConference.colConferenceID = tblSchool.colConferenceID AND tblSurface.colSurfaceID = tblStadium.colSurfaceID AND tblStadium.colStadiumID = tblStadiumSchool.colStadiumID AND tblSchool.colSchoolID = tblStadiumSchool.colSchoolID AND tblSchool.colSchoolName LIKE \\'A％\\ '訂購tblSchool.colSchoolName“;

/* query your db */
if ($result = $mysqli->$sql($sql)) {
    /* fetch associative array */
    while ($row = $sql->fetch_assoc())
    { /* display row */    
        echo '<p>School Name: ' . $row['colSchoolName'] . '</br>Conference: ' . $row['colConferenceName'] . '</br>Class: ' . $row['colClass'] . '</br>Stadium Name: ' . $row['colStadiumName'] . '</br>Address: ' . $row['colAddress'] . '</br>City: ' . $row['colCity'] . '</br>County: ' . $row['colCounty'] . '</br>Region: ' . $row['colRegion'] . '</br>Capacity: ' . $row['colCapacity'] . '</br>Surface Type: ' . $row['colSurfaceName'] . '</br>Surface Company: ' . $row['colSurfaceCompany'] . '</br>Year Installed: ' . $row['colSurfaceYear'] . '</p>';
    }
    /* free result set */
    $result->free();
}
    /* close connection */
    $mysqli->close();

現在我不確定問題是什么。 我一直試圖讓這個工作。 BTW只是讓你知道查詢和連接應該不是問題。 如果他們是我想念的東西，請告訴我。

Answer 1

有你的問題：

if ($result = $mysqli->$sql($sql)) {

您基本上調用的方法與SQL語句的名稱相同，即SELECT tblConference [...] 。 顯然，這種方法不存在。 相反，嘗試mysqli::query ：

if ($result = $mysqli->query($sql)) {

順便說一句，另一個錯誤是在這一行：

while ($row = $sql->fetch_assoc())

$sql仍然是你的SQL語句。 你想要的是迭代你輸入變量$result的mysqli_result對象：

while ($row = $result->fetch_assoc())

Answer 2

這應該做到這一點

$mysqli = new mysqli("localhost", "root", "", "dbstadium");
if (mysqli_connect_errno()) { // check connection
    printf("Connect failed: %s\n", mysqli_connect_error);
    exit();
}
    // your sql query 
    $sql = "SELECT tblConference.colConferenceName, tblSchool.colSchoolName, tblSchool.colClass, tblSurface.colSurfaceName, tblSurface.colSurfaceCompany, tblStadium.colStadiumName, tblStadium.colAddress, tblStadium.colCity, tblStadium.colRegion, tblStadium.colCounty, tblStadium.colCapacity FROM tblStadium, tblConference, tblSurface, tblSchool, tblStadiumSchool WHERE tblConference.colConferenceID = tblSchool.colConferenceID AND tblSurface.colSurfaceID = tblStadium.colSurfaceID AND tblStadium.colStadiumID = tblStadiumSchool.colStadiumID AND tblSchool.colSchoolID = tblStadiumSchool.colSchoolID AND tblSchool.colSchoolName LIKE \'A%\' ORDER BY tblSchool.colSchoolName";
        if ($result = $mysqli->query($sql)) { // query your db
            while ($row = $result->fetch_object())// fetch object
            {  // display row    
                echo "<p><div>School Name: {$row->colSchoolName}</div><div>Conference: {$row->colConferenceName}</div><div>Class: {$row->colClass}</div><div>Stadium Name: {$row->colStadiumName}</div><div>Address: {$row->colAddress}</div><div>City: {$row->colCity}</div><div>County: {$row->colCounty}</div><div>Region: {$row->colRegion}</div><div>Capacity: {$row->colCapacity}</div><div>Surface Type: {$row->colSurfaceName}</div><div>Surface Company: {$row->colSurfaceCompany}</div><div>Year Installed: {$row->colSurfaceYear}</div></p>";
            }//end while loop
            $result->free(); // free result set
        }//end if
$mysqli->close(); // close connection