Question

我有一个数据库的答案，我现在可以数1，但是我想显示选择答案的次数。我不知道该怎么做。例如，我想计算在“ question_id”（问题）中回答“ answer_id”（答案的ID）1和2的次数

我尝试在上面设置一个不同的值，但这对我来说不起作用。

<?php  
$conn = mysqli_connect('localhost', 'root','','survey_cms_4people');
if (!$conn){
    echo "DATABSE ERROR!";
}

$variable = 1;
$countAnswerQuery = "SELECT COUNT(`answer_id`) FROM survey_answers WHERE question_id=$variable AND answer_id=$variable ";
$countanswerresult = mysqli_query($conn, $countAnswerQuery);
while ($row = mysqli_fetch_array($countanswerresult)) {
    echo $row[0];
}


?>

我希望能够自动对它们进行计数，而不是为每个问题/答案写一个sql查询。

Answer 1

例如，我想计算“ question_id”（问题）中“ answer_id”（答案的ID）1和2的回答次数

您可以按question_id和answer_id汇总结果，以找出每个问题为每个答案选择的时间，例如：

SELECT question_id, answer_id, COUNT(*) cnt
FROM survey_answers 
GOUP BY question_id, answer_id

如果yiou要过滤给定的问题，则可以添加WHERE子句：

SELECT question_id, answer_id, COUNT(*) cnt
FROM survey_answers 
WHERE question_id = ?
GOUP BY question_id, answer_id

Answer 2

您要根据答案ID进行分组。

SELECT answer_id, COUNT(*) as count, question_id FROM survey_answers WHERE survey_id = $survey GROUP BY question_id , answer_id ORDER BY count DESC;

这将显示给定调查中所有问题的所有答案的数量。

这可能与以下内容重复

：

MySQL: Count the occurrences of DISTINCT values

我正在计算答案，我不知道该如何自动化

2 个答案: