错误的MYSQL查询
我有一个mysql表,其中“meeting_id”是一个列。 我只需要在表轮询中显示与此会议ID相关的结果 实际查询是:错误的MYSQL查询,mysql,Mysql,我有一个mysql表,其中“meeting_id”是一个列。 我只需要在表轮询中显示与此会议ID相关的结果 实际查询是: $stmt = $pdo->prepare('SELECT p.*, GROUP_CONCAT(pa.title ORDER BY pa.id) AS answers FROM polls p LEFT JOIN poll_answers pa ON pa.poll_id
$stmt = $pdo->prepare('SELECT p.*, GROUP_CONCAT(pa.title ORDER BY pa.id) AS answers
FROM polls p
LEFT JOIN poll_answers pa ON pa.poll_id = p.id
GROUP BY p.id');
我尝试过但没有成功:
$stmt = $pdo->prepare('SELECT p.*, GROUP_CONCAT(pa.title WHERE meeting_id = '.$meeting_id.' ORDER BY pa.id) AS answers
FROM polls p
LEFT JOIN poll_answers pa ON pa.poll_id = p.id
GROUP BY p.id');
谢谢大家WHERE子句不在
GROUP_CONCAT()
中,它在之后从和加入
您还应该使用参数,而不是变量连接
$stmt = $pdo->prepare('SELECT p.*, GROUP_CONCAT(pa.title ORDER BY pa.id) AS answers
FROM polls p
LEFT JOIN poll_answers pa ON pa.poll_id = p.id
WHERE p.meeting_id = :meeting_id
GROUP BY p.id');
$stmt->bindParam(':meeting_id', $meeting_id);
工作完美!非常感谢。