使用 php 从数据库中获取多维数组时出错

Question

有一项数据库考试有 table 考试。
我想运行存储在 $sql_query 中的查询。

它在本地主机 SQL 服务器中显示的输出是：

但是在 php 中使用它时它只显示单行。

$sql_query = "SELECT * FROM exam_timing AS et INNER JOIN exam_details AS ed
  ON et.exam_id = ed.Id WHERE et.Admin_Id = '$username'";
$ids = mysqli_fetch_array(mysqli_query($db_exams, $sql_query), MYSQLI_NUM);

foreach($ids as $id) {
 echo $id," ";
}

这个输出是：

27 113 15:59:00 2020-12-25 30 2 pb 113 php BCA 2 1

它应该显示两行。

Answer 1

mysqli_fetch_array只取结果的first row作为数组，自增结果集行指针

使用函数mysqli_fetch_all

$ids = mysqli_fetch_all(mysqli_query($db_exams, $sql_query), MYSQLI_NUM);

有关 mysqli_fetch_all here

的更多详细信息

Answer 2

问题

您需要用参数替换查询中的每个变量，稍后绑定变量
获取结果的方式
- 您只获取第一个结果行
- 您的循环遍历列而不是结果集

解决方案

// SQL statement
$sql = "
    SELECT *
    FROM exam_timing AS et 
        INNER JOIN exam_details AS ed
            ON et.exam_id = ed.Id
    WHERE et.Admin_Id = ?
";

$query = $mysqli->prepare($sql);    // Prepare the query
$query->bind_param("s", $username); // `s` because you're variable was $username and I've assumed string; use `i` if it's an integer id
$query->execute();                  // Run the query
$result = $query->get_result();     // Get the result set from the database

// Loop through returned result sets
while( $row = $result->fetch_assoc() ){
    // Loop through the columns in the row
    foreach($row as $column){
        echo $column, ' ';
    }
    echo "\n";
}


/* Output:

27 113 15:59:00 2020-12-25 30 2 pb 113 php BCA 2 1
28 114 16:32:00 2021-01-09 23 2 pb 114 php BCA 3 7

*/

使用 php 从数据库中获取多维数组时出错

Error in fetching multidimensional array from database using php

php

mysql

sql

mysqli

问题

解决方案