mysql中的工单号重复

Question

我想看看我的桌子里有没有重复的票号。我下面的代码是显示classes表中的第一个票号1039，如果有重复，我想显示出来。1039不是重复的。我的问题是什么？

$query = "SELECT ticket, COUNT(ticket) AS NumOccurrences FROM classes GROUP BY ticket HAVING (COUNT(ticket) > 1)";
$result = mysql_query($query) or die(mysql_error());    
while($row = mysql_fetch_array($result))    
{
$ticket = $row['ticket'];
}

if($result)
{
echo $ticket. "<br/>";
echo "there are " . mysql_num_rows($result) . " tickets ";
}

else
{
echo "no duplicate ";
}

Answer 1

您需要一个GROUP BY子句，否则将计算所有票证。

SELECT ticket, COUNT(*) c FROM classes GROUP BY ticket HAVING (c > 1)

Answer 2

试一试

SELECT ticket, COUNT(ticket) as `count` FROM classes GROUP BY ticket WHERE `count` > 1