-- 准备工作1：创建事实表数据
CREATE TABLE #StudentSubject
(
StuID INT IDENTITY(1,1) NOT NULL,
StuSubject VARCHAR(500) NOT NULL
)
INSERT INTO #StudentSubject(StuSubject) VALUES ('1')
INSERT INTO #StudentSubject(StuSubject) VALUES ('2')
INSERT INTO #StudentSubject(StuSubject) VALUES ('2,3')
INSERT INTO #StudentSubject(StuSubject) VALUES ('2,3,4')
INSERT INTO #StudentSubject(StuSubject) VALUES ('1,2,3,4')
INSERT INTO #StudentSubject(StuSubject) VALUES ('4')-- 准备工作2：创建维表数据
CREATE TABLE #D_Subject
(
SubjectID INT IDENTITY(1,1) NOT NULL,
SubjectName VARCHAR(500) NOT NULL
)INSERT INTO #D_Subject(SubjectName) VALUES ('语文')
INSERT INTO #D_Subject(SubjectName) VALUES ('数学')
INSERT INTO #D_Subject(SubjectName) VALUES ('英语')
INSERT INTO #D_Subject(SubjectName) VALUES ('体育')SELECT * FROM #StudentSubject
SELECT * FROM #D_Subject
;-- 1分离：将逗号分隔的StuSubject分离匹配StudentSubject获取标签
WITH CetSubject AS
(
SELECT StuID,CAST(LEFT(StuSubject, CHARINDEX(',', StuSubject + ',') - 1) AS NVARCHAR(100)) SubjectID,CAST(STUFF(StuSubject + ',', 1, CHARINDEX(',', StuSubject + ','), '') AS NVARCHAR(100)) SplitFROM #StudentSubjectUNION ALL
SELECT StuID,CAST(LEFT(Split, CHARINDEX(',', Split) - 1) AS NVARCHAR(100)) SIds,CAST(STUFF(Split, 1, CHARINDEX(',', Split), '') AS NVARCHAR(100)) SplitFROM CetSubjectWHERE split > ''
)
-- 2匹配 将分离后的数据逐行与维表匹配
SELECT CS.StuID,DS.SubjectNameINTO #CetSubjectNameFROM CetSubject CSLEFT JOIN #D_Subject DS ON DS.SubjectID = CS.SubjectID WHERE CS.SubjectID <> ''
OPTION (MAXRECURSION 0);-- 3合并 将与维表匹配的结果用逗号分隔合并还原
SELECT StuID,STUFF((SELECT ',' + T.SubjectName FROM #CetSubjectName T WHERE T.StuID = T2.StuID FOR XML PATH('')),1,1,'') SubjectNameFROM #CetSubjectName t2GROUP BY StuIDDROP TABLE #D_Subject
DROP TABLE #StudentSubject
DROP TABLE #CetSubjectName