MySQL将两个表组合在一起，没有重复

Question

是否可以像我的例子中那样组合两个表？

表一：

bibid -- fieldid -- fied_data 
400 ----- 10 ------- 107
400 ------ 5 -------- 1950
400 ------ 3 -------- USA
405 ------ 5 -------- 1997
405 ----- 10 -------- 90
405 ------ 3 -------- RUSSIA

表二：

bibid -------- name
400 --- Postman Always Rings Twice
405 --- Postman is a very good person

结果将是：

bibid --------- name --------------------------length ----------year ---------- country 
400 -- Postman Always Rings Twice --------------107------------1950 ------------USA
405 -- Postman is a very good person -----------90-------------1997 ------------RUSSIA

Answer 1

使用连接来获取数据。

SELECT one.bibid, 
  two.name, 
  one_10.fied_data as length,
  one_5.fied_data as year,
  one_3.fied_data as country  
from table_two two
LEFT OUTER JOIN table_one one
ON one.bibid = two.bibid
LEFT OUTER JOIN table_one one_3
ON one.bibid = one_3.bibid
AND one_3.fieldid = 3
LEFT OUTER JOIN table_one one_5
ON one.bibid = one_5.bibid
AND one_5.fieldid = 5
LEFT OUTER JOIN table_one one_10
ON one.bibid = one_10.bibid
AND one_10.fieldid = 10

但是规范化数据会更好......

BTW：您的意思是field_data而不是fied_data吗？

Answer 2

请尝试以下查询：

select o.bibid, t.name name, 
(case when o.fieldid = 10 then o.fied_data end) length, 
(case when o.fieldid = 5 then o.fied_data end) year,  
(case when o.fieldid = 3 then o.fied_data end)  countrty 
from table_one o, table_two t 
where o.bibid = t.bibid
group by o.bibidid, t.name

Answer 3

看看group_cancat，我的mysql语法太生疏了，无法为你提供一个正确的例子。被困在T-SQL领域的时间太长了。这是一些伪的：

1. 子查询SELECT GROUP_CONCAT(fied_data) FROM T1 GROUP BY bibid
2. 外部查询SELECT [Whatever] FROM T2 JOIN T1 ON ...

基本上你是连接* fied_data *的组，然后查询结果集并加入bibid。