Question

假设2个表：

TABLE: team
-----------
| team_id |
===========
| 1       |
-----------
| 2       |
-----------

TABLE: team_member
-------------------------------------------
| team_member_id | team_id | age | gender |
===========================================
| 1              | 1       | 20  | Male   |
-------------------------------------------
| 1              | 2       | 25  | Male   |
-------------------------------------------
| 1              | 2       | 23  | Female |
-------------------------------------------

我如何搜索这样的内容：

所有仅为男性的球队名单，年龄介于18至25岁之间。
所有男性和女性团队的名单，其中性别在18到25岁之间。
等

我基本上正在寻找有关如何在team的所有子记录中应用某些过滤器（例如年龄）的一般策略。建议？

Answer 1

团队，团队成员

如果您只检查所有男性或所有女性团队，则不能只应用简单的WHERE子句......需要将其与整个团队成员进行比较。尝试

select 
      tm.team_id,
      sum( if( tm.gender = 'Male' AND tm.age between 18 and 25, 1, 0 )) as MaleInRange,
      count(*) AllTeamMembers
  from
      team_member tm
  group by
      tm.Team_ID
  having
      MaleInRange = AllTeamMembers

同样，为了确保你有男性和女性......

select 
      tm.team_id,
      sum( if( tm.age between 18 and 25, 1, 0 )) as AgeInRange,
      sum( if( tm.gender = 'Male', 1, 0 )) as MaleCnt,
      sum( if( tm.gender = 'Female', 1, 0 )) as FemaleCnt,
      count(*) AllTeamMembers
  from
      team_member tm
  group by
      tm.Team_ID
  having
         AgeInRange = AllTeamMembers
     AND MaleCnt > 0
     AND FemaleCnt > 0

Answer 2

像 - SELECT * FROM t1 WHERE key_col＆gt; 1 AND key_col＆lt; 10;

检查此示例 - http://www.roseindia.net/sql/mysql-example/mysql-range.shtml。希望它有所帮助！

Answer 3

您可以按以下方式执行：
1. SELECT * FROM T2 WHERE Gender='Male' and Age BETWEEN 18 AND 25。
2. SELECT * FROM T2 WHERE Age BETWEEN 18 AND 25。
希望它有所帮助！

Answer 4

BTW team_member_id必须是唯一的，否则此列无用!!

所有男性和女性团队的名单，其中性别在18到25岁之间。

SELECT * FROM team_member WHERE Age BETWEEN 18 AND 25 GROUP BY team_id.

结果

| team_member_id | team_id | age | gender |
===========================================
| 1              | 1       | 20  | Male   |
-------------------------------------------
| 1              | 2       | 25  | Male   |
-------------------------------------------

MySQL：搜索儿童记录

4 个答案: