Question

我有FACULTY表，其中包含其他表格的列，以逗号分隔。我想加入各自的表格。

faculty表：

id | name  | course_id | subject_id
a  | smith | 2,3       | 1,2

course表：

id | name
1  | bcom
2  | mcom
3  | bba

subject表：

id | name
1  | account
2  | state
3  | economics

我想从这些表中获得结果，如..

faculty.id, faculty.name, course.name(using faculty.course_id), subject.name(using faculty.subject_id)

我已经尝试了很多查询，也发现了谷歌，但它并没有给我正确的结果。

Answer 1

我认为表现不会太好但值得尝试。此解决方案适用于SQL SERVER：

SELECT *
FROM faculty F
     JOIN course C
         ON ','+F.course_id+',' LIKE '%,'+CONVERT(VARCHAR,C.ID) +',%'
     JOIN subject S
         ON ','+F.subject_id_id+',' LIKE '%,'+CONVERT(VARCHAR,S.ID) +',%'

基于Albin Sunnanbo的评论，我还建议您添加一些太多的表：

<强> fcourses

facultyId 
courseId

和

<强> fsubjects

facultyId
subjectId

这样你就可以进行正确的加入：

SELECT *
FROM faculty F
     JOIN fcourses FC
         ON F.Id = FC.facultyId
     JOIN course C
         ON FC.courseId = C.ID
     JOIN fsubjects FS
         ON F.Id = FS.facultyId
     JOIN subject S
         ON FS.courseId = S.ID

Answer 2

我做过类似的事情：

select f.id, f.lname, f.fname, U.useridlist
from TABLE1 F, TABLE2 U
where ',' || U.useridlist || ',' like '%,' || f.id || ',%'

Answer 3

如果你可以创建一个'string to int table'函数，我会看看以下内容：

创建功能

CREATE  FUNCTION [dbo].[udf_ConvertIntListToTable] (@list varchar(MAX))
RETURNS @tbl TABLE (val int) AS
BEGIN
DECLARE @ix int,
@pos int,
@str varchar(MAX),
@num int
SET @pos = 1
SET @ix = 1
WHILE @ix > 0
BEGIN
SET @ix = charindex(',', @list, @pos)
IF @ix > 0
SET @str = substring(@list, @pos, @ix - @pos)
ELSE
SET @str = substring(@list, @pos, len(@list))
SET @str = ltrim(rtrim(@str))
IF @str LIKE '%[0-9]%' AND
(@str NOT LIKE '%[^0-9]%' OR
@str LIKE '[-+]%' AND
substring(@str, 2, len(@str)) NOT LIKE '[-+]%[^0-9]%')
BEGIN
SET @num = convert(int, @str)
INSERT @tbl (val) VALUES(@num)
END
SET @pos = @ix + 1
END
RETURN
END

然后使用CROSS APPLY

进行查询

declare @FacultyTable table(id int PRIMARY KEY, name nvarchar(50), course_id varchar(50))
declare @CourseTable table(id int PRIMARY KEY, name nvarchar(50))

insert into @FacultyTable values(1, 'Peter Sagal', '11,22')
insert into @FacultyTable values(2, 'Carl Kasell', '22,33')

insert into @CourseTable values(11,'News')
insert into @CourseTable values(22,'News')
insert into @CourseTable values(33,'News')
insert into @CourseTable values(44,'News')


select *
from @FacultyTable f
    CROSS APPLY(
        SELECT *
        FROM @CourseTable c
        WHERE
            c.id IN (SELECT * FROM dbo.udf_ConvertIntListToTable(f.course_id))

    ) tCourses

Answer 4

您可以执行以下查询

  select * from faculty F
     JOIN course C
          on CHARINDEX((','+CAST(c.id as varchar(10))+','), (','+f.courseid+',')) > 0
     JOIN subject s
          on CHARINDEX((','+CAST(s.id as varchar(10))+','), (','+f.subjectid+',')) > 0

使用包含其他表格ID的列连接表格，以逗号分隔

4 个答案: