MySQL查询从多个表中搜索过滤器

我有多个表，我有一个搜索ASP。NET页面，并使用GridView显示结果。GridView必须包含Name, School, State, Country我有多个只包含数据的表:

index_States

indexID| State
----------------
 1     | state1
 2     | state2
 3     | state3

index_Contries

indexID| Country
----------------
 1     | country1
 2     | country2
 3     | country3

index_Schools

indexID| School
----------------
 1     | school1
 2     | school2
 3     | school3

然后我有包含indexID作为引用的表
General_Info

idKey | Name 
--------------
 1    | John
 2    | McClane
 3    | Jr.

Academic_XP

id | idSchool | idState | idCountry | idKey
--------------------------------------------
 1 |    1     |   3     |    20     |  2
 2 |    1     |   5     |    146    |  3
 3 |    2     |   1     |    65     |  9

然后我有一个包含UserType的表，因为只有特定类型的用户才会被搜索

id | UserType | idKey
-----------------------
 1 |    1     |   1
 2 |    3     |   2
 3 |    3     |   3
 4 |    1     |   4

我已经尝试了多个查询，但似乎没有工作。最后一个似乎正在工作的查询是INNER JOIN

SELECT Name, State
FROM General_Info A, Academic_XP B
INNER JOIN index_States D ON B.idState = D.indexID
GROUP BY A.id;

，但它不工作，只要我添加第二个INNER JOIN或WHERE子句。

SELECT Name, State
FROM General_Info A, Academic_XP B, Users
INNER JOIN index_States D ON B.idState = D.indexID
INNER JOIN index_School E ON B.idSchool = E.indexID
GROUP BY A.id
WHERE Users.UserType = 3;

我不知道我该怎么做。所以我想问题是

我怎么能做一个查询，从所有这些表返回像这样的东西?

Name    | State  | School  | Country
---------------------------------------
McClane | state3 | school1 | country20 
Jr.     | state1 | school5 | country146

注意McClane和Jr。都是UserType 3。

SELECT DISTINCT 
       G.Name,
       S.State,
       C.Country,
       SC.School
FROM Academic_XP A
    JOIN Users U ON A.idKey = U.idKey
    JOIN General_Info G ON A.id = G.idKey
    JOIN Index_States S ON A.idState = S.indexID
    JOIN Index_Contries C ON A.idCountry = C.indexID
    JOIN Index_Schools SC ON A.idSchool = SC.indexID
WHERE U.UserType = 3