JOIN 表中的 MySql 查询排序

Question

大家好我有三个 MySql 表

-文档

-文档类型

-组织

我做了这样的查询:

Select Doc.Code,Doc.DataAccept,DocTypes.Name,Org.Name

From Doc,DocTypes,Org

Where Doc.Type=DocTypes.Code AND Doc.Org=Org.Code AND Doc.Code;

在结果中我有

|Code|DataAccept|Name|Name|

17  |    -   |  - |  - | 

18  |    -   |  - |  - | 

24  |    -   |  - |  - | 

26  |    -   |  - |  - | 

32  |    -   |  - |  - | 

代码字段不在系列中

如果进行如下查询

Select Doc.Code,Doc.DataAccept,DocTypes.Name,Org.Name

From Doc,DocTypes,Org

Where Doc.Type=DocTypes.Code AND Doc.Org=Org.Code AND Doc.Code AND Doc.Code < 100;

还好

|Code|DataAccept|Name|Name|

1   |    -   |  - |  - | 

2   |    -   |  - |  - | 

3   |    -   |  - |  - | 

4   |    -   |  - |  - | 

5   |    -   |  - |  - | 

如果 Doc.Code < 1000 则它不在系列中我尝试使用 ORDER BY 代码

Select Doc.Code,Doc.DataAccept,DocTypes.Name,Org.Name

From Doc,DocTypes,Org

Where Doc.Type=DocTypes.Code AND Doc.Org=Org.Code AND Doc.Code AND Doc.Code

ORDER BY Code DESC;

和

Select Doc.Code,Doc.DataAccept,DocTypes.Name,Org.Name

From Doc,DocTypes,Org

Where Doc.Type=DocTypes.Code AND Doc.Org=Org.Code AND Doc.Code AND Doc.Code

ORDER BY Code ASC;

但结果我订购的不是系列

我在这里错过了什么？

感谢您的宝贵时间，请原谅我的英语

"-" - it is a normal data , use it just for represent.

Answer 1

SELECT Doc.Code,Doc.DataAccept,DocTypes.Name,Org.Name

FROM Doc LEFT OUTER JOIN DocTypes JOIN Org

ON Doc.Type=DocTypes.Code AND Doc.Org=Org.Code;

WHERE Doc.Code < 1000 ;

ORDER BY 1

这个explanation可能也有用。