php - PHP 和 mysqli：使用准备好的语句选择多个条件

Question

我正在使用mysqli在 php 文件中使用在InnoDB上运行的数据库来处理一些准备好的语句。大多数语句都运行良好，但是我有一个带有多个条件的 select 语句，它在我的 select 语句中不断返回语法错误，具体来说：? AND section_num = ? AND dept = ? AND semester = ? AND year = ?在第 1 行附近以及以下错误：

Call to a member function bind_param() on a non-object.

这是代码片段：

if (!$rs = $mysqli->query("SELECT id FROM courses WHERE course_num = ? AND section_num = ? AND dept = ? AND semester = ? AND year = ?")) {
        echo "Select Query Failed!: (" . $mysqli->errno . ") ". $mysqli->error;
    }
    if(!$rs->bind_param("ssssi", mysqli_real_escape_string($mysqli,$course_num), mysqli_real_escape_string($mysqli,$section_num),
        mysqli_real_escape_string($mysqli,$dept), mysqli_real_escape_string($mysqli,$semester), mysqli_real_escape_string($mysqli,$year))) {
        echo "Select Binding parameters failed: (" . $rs->errno .") " . $rs->error;
    }
    if (!$rs->execute()) {
        echo "Execute select failed: (" . $rs->errno . ") " . $rs->error;
    }

关于如何形成此语句以根据 4 个输入检索 id 的任何建议都会很棒。谢谢！

Answer 1

您应该使用它prepare来准备一个语句，而不是query仅仅执行一个查询。

Answer 2

$query = "
SELECT id 
FROM courses 
WHERE 
course_num = ? AND section_num = ? AND dept = ? AND semester = ? AND year = ?
";
$rs = $mysqli->prepare($query);
$rs->bind_param("ssssi", $course_num, $section_num, $dept, $semester, $year);
$rs->execute();

Answer 3

更改：$mysqli->query("SELECT id ... 至：$mysqli->prepare("SELECT id ...

Answer 4

这样做很简单

$query = "SELECT * FROM `$table_tran` WHERE `$mem_id` ='$member_id' and                         $status` = '$cur_status'";
$result = mysqli_query($link,$query);

It gets the data from the transaction table using the and statement.