[英]how to rectify cardinality violation error message in php&mysql
我實際上嘗試使用以下sql獲取評論系統的值:
$sql="select * from updates where account_name=:either and type IN ('a', 'c') "
. " union "
. "select * from comment_update where os_id=:statusid and type='b'";
但是發生以下錯誤:
致命錯誤:消息為“ SQLSTATE [21000]”的未捕獲異常“ PDOException”:基數違反:1222在其中使用的SELECT語句具有不同的列數
/opt/lampp/htdocs/project-chg/example.php:21堆棧跟蹤:#0
/opt/lampp/htdocs/project-chg/example.php(21):PDOStatement-> execute()
在第21行的/opt/lampp/htdocs/project-chg/example.php中拋出#1 {main}
那么我該怎么做才能糾正此錯誤,以及如何在適當的帖子中顯示評論? [edit]:感謝指出差異@Jakar現在,我在研究網絡上的其他資源后遇到了一個新問題,我加入了連接,結果即將來臨,但是現在的問題是,所有帖子的結果似乎都在打印。 而不是張貼在應附加的位置。 好像我搞砸了循環,你能為我指出正確的循環嗎??? 這是代碼:
<?php
$status2view=$project->statusView($_SESSION['uname']);
foreach($status2view as $row){
//print_r($row);
$status_id=$row['update_id'];
// SELECT * FROM Product,Color WHERE Product.Name = Color.Name
$sql="select update_id,update_body, time, title, author,type from updates where account_name=:either and type IN ('a', 'c') "
. " union "
. "select comment_id, author,time,comment_body,os_id ,type from comment_update where os_id=:statusid and type='b'";
$sql1="select comment_update.comment_id, comment_update.author,comment_update.time,comment_update.comment_body,comment_update.os_id ,comment_update.type from updates,comment_update where comment_update.os_id like updates.update_id ";
$stmth=$conn->prepare($sql1);
// $stmth->bindparam(":either",$_SESSION['uname']);
//$stmth->bindparam(":statusid",$status_id);
$stmth->execute();
$status_reply= $stmth->fetchAll(PDO::FETCH_ASSOC);
?>
</div>
<div class="col-lg-8">
<?php
foreach ($status_reply as $row1) {
$status_reply_id=$row1['comment_id'];
$reply_author=$row1['author'];
$reply_d=htmlentities($row1['comment_body']);
$reply_data= stripslashes($reply_d);
$reply_osid=$row1['os_id'];
$reply_date=$row1['time'];
$reply_delete_button="";
if ($reply_author==$_SESSION['uname'] || $account_name==$_SESSION['uname']) {
$reply_delete_button.="<li><span id='$status_reply_id' class='delete_reply_btn glyphicon glyphicon-remove'><a href='#' title='Delete this comment'>Remove X</a></span></li>";
}
$status_replies="<div class='replyboxes pull-left reply_".$status_reply_id."'><b>Reply by:-<a href='search_results.php?u=".$reply_author."'>".$reply_author."</a>"
. "<span class='pull-right'>".$reply_date
. "<b class='caret'>
<small><span class='btn-xs btn-danger dropdown-toggle pull-right' data-toggle='dropdown' aria-expanded='true' ><span class='glyphicon glyphicon-edit'></span>
<ul class='dropdown-menu'>".$reply_delete_button
. "<li><a href='#' class='hidden_text_area glyphicon glyphicon-pencil reply_".$status_reply_id."' title='Edit this comment' >Edit</a></li>"
. "<li><a href='report.php?u='".$reply_author."'>Report</a><li></ul>"
. "</span></span></small></b><br><legend>". html_entity_decode($reply_data)."</legend><br></div>";
}
foreach($status2view as $row){
$updateid=$row['update_id'];
$account_name=$row['account_name'];
$os_id=$row['os_id'];
$author=$row['author'];
$post_date=$row['time'];
$title= stripslashes($row['title']);
$data= stripslashes($row['update_body']);
$statusdeletebutton='';
//insert_status_ui script to get message.
if ($author==$_SESSION['uname'] || $account_name==$_SESSION['uname']) {
$statusdeletebutton='<li>'
. '<a href="#" type="'.$updateid.'" class="delete_4_session hidden_text_delete_'.$updateid.' glyphicon glyphicon-trash delete_reply_btn" title="Delete this status and its replies">Remove</a></li>';
}
$status_list= $statusui_edit.'<div attr="'.$updateid.'" type="'.$updateid.'" class="statusboxes status_'.$updateid.' jumbotron">'
. '<h3 style="color:black; margin-bottom:5px; margin-top:5px;" class="pull-left">'
. '<div id="'.$updateid.'" class="title_s_2copy" value="'.html_entity_decode($title).'">'.html_entity_decode($title).'</div></h3>'
. '<span class="pull-right">'
. '<div class="dropdown">'
. '<button type="button" class="btn btn-danger dropdown-toggle" data-toggle="dropdown" >'
. '<span class="glyphicon glyphicon-edit"></span></button>'
. '<ul class="dropdown-menu">'
. '<li><a href="#" attr="'.$updateid.'" type="'.$updateid.'" class="edit_4_session hidden_text_edit glyphicon glyphicon-pencil" title="Edit this status" >Edit</a></li>'.$statusdeletebutton.'</ul></div></span><br><hr>'
. '<legend><span class=" data_s_2copy" type="'.$updateid.'" >'
. html_entity_decode($data).'</span><br><br></legend><b style="text-align:right; color:black;"><small>Posted by:- <a href="search_results.php?u='.$author.'">'.$author. '</a> '.$post_date.'</small></b>'
. '<br><p>'.$status_replies.'</p><br>';
$status_list.= '<textarea id="reply_textarea_'.$updateid.'" class="status_reply_'.$updateid.' input-custom2" placeholder="comment\'s"></textarea>'
. '<button id="reply_btn_'.$updateid.'" attr="'.$updateid.'" type="b" class="btn btn-warning pull-right btn-sm reply_btn reply_'.$updateid.'">Reply</button></div>';
echo $status_list;
}
}
當您使用UNION
,它會組合結果集,並且要這樣做,每個列的列數必須相同。 因此,您不應SELECT *
,而應SELECT col1,col2,col3
或任何列名。 (無論如何,使用SELECT *
不好的做法,因為它降低了代碼的可讀性,並使PHP與數據庫模式更緊密地耦合在一起)。
我不知道您的表結構是什么樣的,因此很難給出一個完美的答案,但是我建議運行兩個查詢:
$sql =
"SELECT column_list... FROM updates
WHERE account_name LIKE :either AND type IN ('a','c');"
."SELECT column_list... FROM comment_update
WHERE os_id=:statusid AND type LIKE 'b';"
否則,如果您確實確實需要(或希望使用) UNION
,則類似於:
SELECT name,content,id FROM updates...
UNION
SELECT name,content,id FROM comment_update...
因為這樣,兩個選擇上的列數都相同。
另外,與char/varchar
列進行比較時,最好使用LIKE
不是=
。
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