SQL SELECT錯誤

Question

這個select語句有什麼問題？我得到這個錯誤：警告：mysqli_num_rows（）期望參數1爲mysqli_result，布爾給定。我嘗試了一切，但無法弄清楚。幫助將不勝感激！

  $sql = "SELECT gm.gname, gp.logo 
     FROM gmembers AS gm 
     LEFT JOIN groups AS gp ON gp.name = gm.gname 
     WHRER gm.mname ='$log_username'"; 
$query = mysqli_query($db_conx, $sql); 
$g_check = mysqli_num_rows($query); 

Answer 1

你有一個錯字

SELECT gm.gname, gp.logo 
FROM gmembers AS gm 
LEFT JOIN groups AS gp ON gp.name = gm.gname 
WHERE gm.mname ='$log_username' 

嘗試在phpMyAdmin的/GUI無論您正在使用的數據庫運行此。