Question

输入表：提交

提交包含四列，Contestant_id表示针对不同问题提交的不同参赛者的ID。一个参赛者可以多次提交一个问题。因此，challenge_id可能不止一次出现在Contestant_id上。

 submission_id  Contestant_id challenge_id    score
    11                 1             333        90
    22                 2             333        60
    33                 3             333        80
    44                 4             333         0
    112                1             333        45
    113                1             444        80
    114                2             444        70

输出表：总得分

Contestant_id     score 
    1              170
    2              130
    3               80

在这里，我们将总分作为 -

 for contestant_id 1 :  total score = max(90,45)+ 80 = 170
 for contestant_id 2 :  total score = 60 + 70 = 130
 for contestant_id 3 :  total score = 80 
 for contestant_id 4 :  total score = 0 ;so we exclude it

为了获得总分，如果有多个相同的challenge_id，我必须占用最多一个参赛者_id，而不是花一笔钱。但是，我被困在了，怎么办。

选择Contestant_id，得分为（选择总和（最大值（选择....）

Answer 1

您似乎需要两个级别的聚合。您需要每位参赛者和挑战赛的最高分。然后你想要添加它们。

这是一种方法：

select Contestant_id, sum(max_score)
from (select Contestant_id, challenge_id, max(score) as max_score
      from Submissions
      group by Contestant_id, challenge_id,
     ) t
group by Contestant_id;

如果您想创建输出表格，可以在into total_scores之后添加select。

Answer 2

使用CTE

08:32:54,297 INFO  [org.jboss.as.server] (DeploymentScanner-threads - 2) JBAS018559: Deployed "HelloJPAHibernate.war"
08:33:01,282 INFO  [org.hibernate.annotations.common.Version] (http-localhost-127.0.0.1-8080-1) HCANN000001: Hibernate Commons Annotations {4.0.4.Final}
08:33:01,290 INFO  [org.hibernate.Version] (http-localhost-127.0.0.1-8080-1) HHH000412: Hibernate Core {4.3.5.Final}
08:33:01,293 INFO  [org.hibernate.cfg.Environment] (http-localhost-127.0.0.1-8080-1) HHH000205: Loaded properties from resource hibernate.properties: {hibernate.connection.driver_class=org.h2.Driver, hibernate.service.allow_crawling=false, hibernate.dialect=org.hibernate.dialect.H2Dialect, hibernate.max_fetch_depth=5, hibernate.format_sql=true, hibernate.generate_statistics=true, hibernate.connection.username=sa, hibernate.connection.url=jdbc:h2:mem:db1;DB_CLOSE_DELAY=-1;MVCC=TRUE, hibernate.bytecode.use_reflection_optimizer=false, hibernate.jdbc.batch_versioned_data=true, hibernate.connection.pool_size=5}
08:33:01,297 INFO  [org.hibernate.cfg.Environment] (http-localhost-127.0.0.1-8080-1) HHH000021: Bytecode provider name : javassist
08:33:01,317 INFO  [org.hibernate.cfg.Configuration] (http-localhost-127.0.0.1-8080-1) HHH000043: Configuring from resource: /hibernate.cfg.xml
08:33:01,318 INFO  [org.hibernate.cfg.Configuration] (http-localhost-127.0.0.1-8080-1) HHH000040: Configuration resource: /hibernate.cfg.xml
08:33:01,366 INFO  [org.hibernate.cfg.Configuration] (http-localhost-127.0.0.1-8080-1) HHH000041: Configured SessionFactory: null
08:33:01,453 WARN  [org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl] (http-localhost-127.0.0.1-8080-1) HHH000402: Using Hibernate built-in connection pool (not for production use!)
08:33:01,455 INFO  [org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl] (http-localhost-127.0.0.1-8080-1) HHH000401: using driver [com.microsoft.sqlserver.jdbc.SQLServerDriver] at URL [jdbc:sqlserver://localhost:1433;database=ccc]
08:33:01,457 INFO  [org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl] (http-localhost-127.0.0.1-8080-1) HHH000046: Connection properties: {user=lm, password=****}
08:33:01,458 INFO  [org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl] (http-localhost-127.0.0.1-8080-1) HHH000006: Autocommit mode: false
08:33:01,460 INFO  [org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl] (http-localhost-127.0.0.1-8080-1) HHH000115: Hibernate connection pool size: 5 (min=1)
08:33:03,123 INFO  [org.hibernate.dialect.Dialect] (http-localhost-127.0.0.1-8080-1) HHH000400: Using dialect: org.hibernate.dialect.SQLServer2008Dialect
08:33:03,255 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/HelloJPAHibernate].[Faces Servlet]] (http-localhost-127.0.0.1-8080-1) Servlet.service() for servlet Faces Servlet threw exception: java.lang.NoSuchMethodError: javax.persistence.Table.indexes()[Ljavax/persistence/Index;
at org.hibernate.cfg.annotations.EntityBinder.processComplementaryTableDefinitions(EntityBinder.java:936) [hibernate-core-4.3.5.Final.jar:4.3.5.Final]
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:824) [hibernate-core-4.3.5.Final.jar:4.3.5.Final]
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processAnnotatedClassesQueue(Configuration.java:3788) [hibernate-core-4.3.5.Final.jar:4.3.5.Final]
at org.hibernate.cfg.Configuration$MetadataSourceQueue.processMetadata(Configuration.java:3742) [hibernate-core-4.3.5.Final.jar:4.3.5.Final]
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1410) [hibernate-core-4.3.5.Final.jar:4.3.5.Final]
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1844) [hibernate-core-4.3.5.Final.jar:4.3.5.Final]
at com.esprit.dao.EntityDao.getSessionFactory(EntityDao.java:48) [classes:]
at com.esprit.dao.EntityDao.openCurrentSession(EntityDao.java:25) [classes:]
at com.esprit.dao.EntityService.findAllPersons(EntityService.java:86) [classes:]
at com.esprit.crud.dynamic.DataModelBeanD.init(DataModelBeanD.java:37) [classes:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_55]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) [rt.jar:1.7.0_55]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) [rt.jar:1.7.0_55]
at java.lang.reflect.Method.invoke(Unknown Source) [rt.jar:1.7.0_55]

查询总分

2 个答案: