MSSQL2005行列转换(使用PIVOT and UNPIVOT)

PIVOT syntax:

SELECT ..... FROM pivoted_table
pivoted_table ::= table_source PIVOT <pivot_clause> table_alias
table_source ::= table,view, sub-query,XML......, 即SQL语句From关键字后可以跟的所有东西，定义太复杂，这里就不写了
pivot_clause ::=( aggregate_function ( value_column )
FOR pivot_column
IN ( <column_list> )
)

UNPIVOT syntax:
SELECT ..... FROM unpivoted_table
unpivoted_table ::= table_source UNPIVOT <unpivot_clause> table_alias
table_source ::= Table, view, sub-query, XML..., 即SQL语句From关键字后可以跟的所有东西，定义太复杂，这里就不写了
unpivot_clause ::= ( value_column FOR pivot_column IN ( <column_list> ) )

PIVOT example：
CREATE TABLE Score ( StuNo varchar(10), StuName varchar(50), CourseName varchar(50), Score int);
GO
INSERT INTO Score (StuNo, StuName, CourseName, Score) VALUES ('1', 'Tom', 'Math', 80);
INSERT INTO Score (StuNo, StuName, CourseName, Score) VALUES ('1', 'Tom', 'English', 82);
INSERT INTO Score (StuNo, StuName, CourseName, Score) VALUES ('1', 'Tom', 'Geography', 84);
INSERT INTO Score (StuNo, StuName, CourseName, Score) VALUES ('2', 'Jone', 'Math', 79);
INSERT INTO Score (StuNo, StuName, CourseName, Score) VALUES ('2', 'Jone', 'English', 88);
INSERT INTO Score (StuNo, StuName, CourseName, Score) VALUES ('2', 'Jone', 'Geography', 86);
GO

SELECT * FROM Score;

StuNo StuName CourseName Score
1 Tom Math 80
1 Tom English 82
1 Tom Geography 84
2 Jone Math 79
2 Jone English 88
2 Jone Geography 86

--Change row to column:
SELECT StuNo, StuName, Math, English, Geography
FROM Score
PIVOT ( MAX(Score) FOR CourseName in (Math, English, Geography) ) AS ScoreList
ORDER BY StuNo;

StuNo StuName Math English Geography
1 Tom 80 82 84
2 Jone 79 88 86

DROP TABLE Score;
GO

UNPIVOT example:
CREATE TABLE ScoreList ( StuNo varchar(10), StuName varchar(50), Math int, English int, Geography int);
GO
INSERT INTO ScoreList (StuNo, StuName, Math, English, Geography) VALUES ('1', 'Tom', 80, 82, 84);
INSERT INTO ScoreList (StuNo, StuName, Math, English, Geography) VALUES ('2', 'Jone', 79, 88, 86);
GO

SELECT * FROM ScoreList;

StuNo StuName Math English Geography
1 Tom 80 82 84
2 Jone 79 88 86

--Change column values to row:
SELECT StuNo, StuName, CourseName, Score
FROM ScoreList
UNPIVOT ( Score FOR CourseName in (Math, English, Geography) ) AS ScorePvtTable
ORDER BY StuNo;

StuNo StuName CourseName Score
1 Tom Math 80
1 Tom English 82
1 Tom Geography 84
2 Jone Math 79
2 Jone English 88
2 Jone Geography 86

DROP TABLE ScoreList;
GO