[英]How to select comments with child comments from MySQL?
我有两个表:
'评论'
| id | content | user_id | article_id | parent_id |
“用户”
| id | name | photo |
我的查询是:
<?php
$query = mysql_query("SELECT comments.id, comments.content, users.name,
users.photo FROM comments, users WHERE comments.article_id = '".$get_id."'
AND comments.parent_id = 0 AND comments.user_id = users.id");
while($res = mysql_fetch_assoc($query))
{
$id = $res['id'];
$content = $res['content'];
$name = $res['name'];
$photo = $res['photo'];
echo $photo;
echo $name;
echo $content;
$query2 = mysql_query("SELECT comments.id, comments.content, users.name,
users.photo FROM comments, users WHERE comments.article_id = '".$get_id."'
AND comments.parent_id = '".$id."' AND comments.user_id = users.id");
while($res2 = mysql_fetch_assoc($query2))
{
$id2 = $res2['id'];
$content2 = $res2['content'];
$name2 = $res2['name'];
$photo2 = $res2['photo'];
echo $photo2;
echo $name2;
echo $content2;
}
}
?>
它不能正常工作。 尽管有多个子注释,但每个嵌套中显示1个父注释和1个子注释。
如何解决并最小化它? 是否可以仅使用一个查询来完成?
谢谢!
JOIN
本身的表。
将查询更改为:
SELECT comments.id, comments.content, users.name,
users.photo FROM comments JOIN users ON comments.user_id = users.id JOIN
comments c ON comments.id =
c.parent_id WHERE
comments.article_id = '".$get_id."'
AND comments.parent_id = '".$id."'
您不需要第二个查询,这是完整的代码:
<?php
$query = mysql_query("SELECT comments.id, comments.content, users.name,
users.photo FROM comments JOIN users ON comments.user_id = users.id JOIN
comments c ON comments.id =
c.parent_id WHERE
comments.article_id = '".$get_id."'");
while($res = mysql_fetch_assoc($query))
{
$id = $res['id'];
$content = $res['content'];
$name = $res['name'];
$photo = $res['photo'];
echo $photo;
echo $name;
echo $content;
}
?>
只需使用JOIN即可获取注释以及所有子项。
SELECT users.id userID, users.name, users.photo , childrenComments.*,
parentComments.id cpId, parentComments.content cpContent,
parentComments.user_id cpUser_id,parentComments.article_id cpArticleId
FROM users JOIN (SELECT * FROM Comment WHERE id=0) parentComments
ON users.id=parentComments.user_id LEFT JOIN Comment childrenComments
ON parentComments.id=childrenComments.parent_id;
然后,您可以遍历结果以适当地打印它。 这样会更好,因为您只需要运行一个查询即可。
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