arrays - 计算数据库中的重复条目

Question

我想计算一个邮政编码输入数据库的次数。我不确定我是否使用了正确的功能。此外，最终我需要将邮政编码按输入数据库的年份分开。我知道如何分开岁月。我真正需要帮助的是计算重复条目。这是我的代码。

$sql = 'SELECT * FROM zip ORDER BY time_register'; 
$result = mysql_query($sql,$db) or die(mysql_error(). "<br />SQL: $sql");
$row = mysql_fetch_array($result);

do{
    $visitor_zip= array();
    $register = $row['time_register'];
    $register_year = date(Y,$register);

    print_r(array_count_values($visitor_zip));

} while($row = mysql_fetch_array($result))

---

答案：这是我的有效代码。

$sql = "SELECT `visitor_zip` AS `zip`, COUNT(`visitor_zip`) AS `cnt`
        FROM `zip`
        GROUP BY `visitor_zip`
        ORDER BY visitor_zip";

$result = mysql_query($sql,$db) or die(mysql_error(). "<br />SQL: $sql");

print '<table class="zip"><tr><td><b>Zip</b></td><td># of</td></tr>';
while($row = mysql_fetch_array($result)) {
    print '<tr><td>' . $row['zip'] .'</td><td>'.  $row['cnt'] . '</td></tr>';
}
print '</table>';

Answer 1

我认为这应该有效：

SELECT COUNT(*) AS cnt, zipcode FROM zip
GROUP BY zipcode
ORDER BY time_register

Answer 2

select count(ZIPCODEFIELD) as cnt, ZIPCODEFIELD, time_register FROM zip
GROUP BY zipcode,time_register