我收到下面列出的以下警告,我想知道如何解决它
Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given on line 65
该代码围绕下面列出的PHP代码这一部分。如果需要,我可以列出完整的代码。
// function to retrieve average and votes function getRatingText(){ $dbc = mysqli_connect ("localhost", "root", "", "sitename"); $sql1 = "SELECT COUNT(*) FROM articles_grades WHERE users_articles_id = '$page'"; $result = mysqli_query($dbc,$sql1); $total_ratings = mysqli_fetch_array($result); $sql2 = "SELECT COUNT(*) FROM grades JOIN grades ON grades.id = articles_grades.grade_id WHERE articles_grades.users_articles_id = '$page'"; $result = mysqli_query($dbc,$sql2); $total_rating_points = mysqli_fetch_array($result); if (!empty($total_rating_points) && !empty($total_ratings)){ $avg = (round($total_rating_points / $total_ratings,1)); $votes = $total_ratings; echo $avg . "/10 (" . $votes . " votes cast)"; } else { echo '(no votes cast)'; } }
mysqli_query()``FALSE如果查询中有错误,则返回。所以你应该测试一下…
mysqli_query()``FALSE
/* Select queries return a resultset */ if ($result = mysqli_query($dbc, "SELECT Name FROM City LIMIT 10")) { printf("Select returned %d rows.\n", $result->num_rows); /* free result set */ $result->close(); }
请参阅此链接以获取mysqli_query参考 http://php.net/manual/zh/mysqli.query.php
mysqli_query