工會

Question

我將如何分辨其中一條記錄從下面的例子聯合查詢來區分內兩個查詢：

SELECT id, name, datetime FROM events 
UNION 
SELECT id, name, datetime FROM festival 
ORDER BY datetime DESC 

我使用它在PHP的方式是：

$stmt = $cxn->prepare('SELECT id, name, datetime FROM events WHERE id = ? UNION SELECT id, name, datetime FROM festival WHERE id = ? ORDER BY datetime DESC'); 
$stmt->bind_param('i', $event_id); 
$stmt->execute(); 
$stmt->store_result(); 
$stmt->bind_result($id, $name, $datetime); 

while ($stmt->fetch()) { 
    echo "ID: " . $id . "\n"; 
    echo "Name: " . $name . "\n"; 
    echo "Date: " . $datetime; 
} 

$stmt->close(); 

請幫我一把。

謝謝。

Answer 1

SELECT id, name, datetime, 'events' FROM events 
UNION 
SELECT id, name, datetime, 'festival' FROM festival 
ORDER BY datetime DESC 

PHP

$stmt = $cxn->prepare('SELECT id, name, datetime, "events" as tablename FROM events WHERE id = ? UNION SELECT id, name, datetime, "festival" as tablename FROM festival WHERE id = ? ORDER BY datetime DESC'); 
$stmt->bind_param('i', $event_id); 
$stmt->execute(); 
$stmt->store_result(); 
$stmt->bind_result($id, $name, $datetime, $table); 

while ($stmt->fetch()) { 
    echo "ID: " . $id . "\n"; 
    echo "Name: " . $name . "\n"; 
    echo "Date: " . $datetime; 
    echo "Which Table: " . $table; 
} 

$stmt->close(); 

Answer 2

，你可以通過添加一個多列做到這一點，區分它想：如果

SELECT id, name, datetime, 'E' as fromwhere FROM events 
UNION 
SELECT id, name, datetime,'F' as fromwhere FROM festival 
ORDER BY datetime DESC 

的fromwhere欄會告訴你從事件或節日它。