PHP 从两个表中选择并回显表名

Question

我正在使用此 PHP 代码通过 UNION 从 MySQL 中的 2 个表中进行选择

$sql="
    SELECT 
    'ticket_updates' as rowTable,
    sequence, 
    ticket_seq, 
    notes as displaydata, 
    datetime as timestamp, 
    updatedby, 
    CONCAT('<strong>Time Start: </strong>',timestart,' - <strong>Time End: </strong>',timeend) as timestartend
    from ticket_updates where ticket_seq = '".$_GET["seq"]."'

    UNION

    SELECT 
    'ticket_changes' as rowTable,
    sequence, 
    ticket_seq, 
    description as displaydata, 
    datetime as timestamp,  
    changed_by as updatedby, 
    blankfield
    from ticket_changes where ticket_seq = '".$_GET["seq"]."' 

    ORDER by timestamp ASC ";

$stmt = $pdo_conn->prepare($sql);
$stmt->execute(array(':ticket_seq' => $_GET["seq"]));
$records = $stmt->fetchAll(PDO::FETCH_ASSOC);
$num_rows = count($records);
foreach ($records as $result2) {
   echo $result2["rowTable"];
}

但它不回显 ticket_updates 或 ticket_changes

我知道有行被返回，因为当我在 phpMyAdmin 中运行查询时，它显示行并且显示 ticket_updates 或 ticket_changes

Answer 1

您的 SQL 中没有任何占位符来匹配 execute 调用中的参数。试试这个:

$sql="
    SELECT 
    'ticket_updates' as rowTable,
    sequence, 
    ticket_seq, 
    notes as displaydata, 
    datetime as timestamp, 
    updatedby, 
    CONCAT('<strong>Time Start: </strong>',timestart,' - <strong>Time End: </strong>',timeend) as timestartend
    from ticket_updates where ticket_seq = :ticket_seq1

    UNION

    SELECT 
    'ticket_changes' as rowTable,
    sequence, 
    ticket_seq, 
    description as displaydata, 
    datetime as timestamp,  
    changed_by as updatedby, 
    blankfield
    from ticket_changes where ticket_seq = :ticket_seq2 

    ORDER by timestamp ASC ";

$stmt = $pdo_conn->prepare($sql);
$stmt->execute(array(':ticket_seq1' => $_GET["seq"], ':ticket_seq12' => $_GET["seq"]));

您需要两个不同的占位符，不能使用同一个占位符两次。