mysql - 如何在sql中的单个查询中获取具有多个值的名称

Question

我有两个表:Person、PersonType

    Person                         PersonType                          PersonTypeMapping
personId   name                 typeId     typeName                tId   personId   typeId
  101         p1                  1        Student                 123       101       1
  102         p2                  2        Employee                124       102       1
  103         p3                                                   125       102       2
                                                                   126       103       1
                                                                   127       103       2

现在我需要获取人名及其相应的类型名称。

这是我的查询

SELECT Person.personId, Person.name,PersonType.typeName 
from Person 
    INNER JOIN PersonTypeMapping ON PersonTypeMapping.personId = Person.personId 
    INNER JOIN PersonType ON PersonType.typeId = PersonTypeMapping.typeId; 

我的输出:

   personId       name        typeName
   101             p1          Student
   102             p2          Student
   102             p2          Employee
   103             p3          Student
   103             p3          Employee

但我需要这样的输出:

   personId       name        typeName
   101             p1          Student
   102             p2          Student, Employee
   103             p3          Student, Employee

为此可以做什么？

Answer 1

SELECT Person.personId, Person.name, Group_Concat(PersonType.typeName) 
from Person 
    INNER JOIN PersonTypeMapping ON PersonTypeMapping.personId = Person.personId 
    INNER JOIN PersonType ON PersonType.typeId = PersonTypeMapping.typeId
GROUP BY Person.personId, Person.name;