SQL选择最大计数嵌套？

Question

SELECT N.National_PosID, N.Title, C.First_Name, C.Mid_Name, C.Last_Name, count(*)  
FROM National_Position N, Candidate C, Vote V
WHERE N.National_PosID = C.National_PosID AND V.Candidate_ID = C.Candidate_ID
Group by N.National_PosID, N.Title, C.First_Name, C.Mid_Name, C.Last_Name;

输出

+------------+------------+----------+-----------+----------+
| Title      | First_Name | Mid_Name | Last_Name | count(*) |
+------------+------------+----------+-----------+----------+
| Agueda     | Sarahann   |          | MCMAHON   |      557 |
| Amesha     | Maurice    |          | GREEN     |     1071 |
| Kiante     | Jesicca    |          | WINTERS   |      482 |
| Kieffer    | Serene     |          | HIGGINS   |     1285 |
| Koray      | Ahley      |          | COLLIER   |     1287 |
| SENATE     | Daisy      | Hao      | MADDOX    |     1316 |
| SENATE     | Radhames   | Jakson   | MURILLO   |     1269 |
| SENATE     | Rayan      | Kaitlynn | FRYE      |     1089 |
| SENATE     | Rio        | Krysti   | HUGHES    |      457 |
| SENATE     | Shalondra  | Nila     | HORTON    |      551 |
+------------+------------+----------+-----------+----------+
10 rows in set (1.33 sec)

问题是如何获得最大计数的输出？

Answer 1

您可以使用subquery获得原始结果的max count。

SELECT t1.National_PosID, t1.Title, t1.First_Name, t1.Mid_Name, t1.Last_Name, max(ct)
FROM(
    SELECT N.National_PosID, N.Title, C.First_Name, C.Mid_Name, C.Last_Name, count(*) ct 
    FROM National_Position N
    INNER JOIN Candidate C ON N.National_PosID = C.National_PosID
    INNER JOIN Vote V ON V.Candidate_ID = C.Candidate_ID  
    INNER JOIN      
    GROUP BY N.National_PosID, N.Title, C.First_Name, C.Mid_Name, C.Last_Name) as t1
GROUP BY t1.National_PosID, t1.Title, t1.First_Name, t1.Mid_Name, t1.Last_Name