Question

希望列出所有问题以及个人的所有答案。
我不知道我应该使用还是内部选择。

Tbquestions
id - 成员 - 问题 - 标题

Tbanswers
id - 成员 - 回答 - 标题

只需要获得每个表的标题

Answer 1

尝试此查询：

SELECT id,member,'Q' as Type, question as QA FROM Tbquestions
WHERE member='member1'
UNION ALL
SELECT id,member,'A' as Type, answer as QA FROM Tbanswers
WHERE member='member1'

示例输出：

id   member   Type   QA
1    Name1    Q      What is it?
3    Name4    Q      Who are you?
1    Name2    A      My name is Name2
4    Name3    A      He is dead, Jim.

修改

为每个查询添加Limit子句，以查找5个问题和10个答案：

SELECT id,member,'Q' as Type, question as QA FROM Tbquestions WHERE member='member1' LIMIT 5 UNION ALL SELECT id,member,'A' as Type, answer as QA FROM Tbanswers WHERE member='member1' LIMIT 10

Answer 2

如果问题与相应答案之间存在关联，则应该加入。由于表格与会员ID相关，我不认为应该使用联接。而是使用UNION ALL

简单地选择并组合来自两个表的结果集

Answer 3

global $mysqli;

$stmt = $mysqli->prepare("SELECT title from Tbquestions WHERE member = ?");
$stmt->bind_param('s',$member);
if($stmt->execute()){
$stmt->bind_result($questions);
$stmt->close();
}
$stmt = $mysqli->prepare("SELECT title from Tbanswers WHERE member = ?");
$stmt->bind_param('s',$member);
if($stmt->execute()){
$stmt->bind_result($answers);
$stmt->close();
}
$allposts = array_merge($questions, $answers);
echo '<pre>';
print_r($allposts, false);

列出2个表中成员的所有内容（问题，答案）

3 个答案: