Question

从下表中，我想计算1）不同名称的数量和2）每个名称的出现次数。

+------+------+-------+-------+-------+-------+-------+
| date | job  |person1|person2|person3|person4|person5|
+------+------+-------+-------+-------+-------+-------+
| mon  | clean|  Matt | Bruce | Alan  |Emilce | Linda |
+------+------+-------+-------+-------+-------+-------+
| tu   | write| Bruce |  Matt |  Matt | Alan  | Linda |
+------+------+-------+-------+-------+-------+-------+
| wen  | mend | Bruce |Emilce |  Matt |  Matt | Linda |
+------+------+-------+-------+-------+-------+-------+
| fri  | sew  |  Matt | Linda |Emilce | Alan  | Alan  |
+------+------+-------+-------+-------+-------+-------+

输出应为：
姓名：5

每个名称的出现次数：

+------+------+
| Alan |  4   |
+------+------+
| Bruce|  3   |
+------+------+
|Emilce|  3   |
+------+------+
| Linda|  4   |
+------+------+
| Matt |  5   |
+------+------+

我一直在尝试

SELECT user, count(*) AS count
FROM (
SELECT person1 AS user FROM mytable
UNION ALL
SELECT person1 FROM mytable
UNION ALL
SELECT person3 FROM mytable
UNION ALL
SELECT person4 FROM mytable
UNION ALL
SELECT person5 FROM mytable
) AS all_users
GROUP BY user
ORDER BY user

但我不知道如何知道表中的名字数量，我想知道数组中每个名字的出现次数。

Answer 1

这是你想要的吗？

SELECT count(distinct user) as NumNames
FROM (
SELECT person1 AS user FROM mytable
UNION ALL
SELECT person1 FROM mytable
UNION ALL
SELECT person3 FROM mytable
UNION ALL
SELECT person4 FROM mytable
UNION ALL
SELECT person5 FROM mytable
) all_users

Answer 2

以上代码实际上正在运作 mysql_result（$ Persons，0,1）确实是表中存在的名称总数因此，您可以循环获取所有名称/出现对我没注意到。
道歉。

$Persons=mysql_query('SELECT user, count(*) AS count
FROM (
SELECT person1 AS user FROM mytable
UNION ALL
SELECT person1 FROM mytable
UNION ALL
SELECT person3 FROM mytable
UNION ALL
SELECT person4 FROM mytable
UNION ALL
SELECT person5 FROM mytable
) AS all_users
GROUP BY user
ORDER BY user');

$TotalPersons=mysql_result($Persons,0,1);

for ($i=0;$i<=$TotalPersons;$i++) {
   $Name[$i]=mysql_result($Persons,$i+1);
   $Occurences[$i]=mysql_result($Persons,$i+1,1);

   echo "<br> Number".$i.": ".$Name[$i].": ".$Occurences[$i]."<br>";
}

SQL计数出现多个列

2 个答案: