grammar:
PIVOT for rotating the column value for a column name (i.e., column lines switch), the SQL Server 2000 can be implemented with the CASE statement with aggregate function
PIVOT general syntax is: PIVOT (aggregate function (column) Column the FOR in (...)) AS P
The complete syntax:
table_source
PIVOT(
Aggregate functions (value_column in)
FOR pivot_column
IN(<column_list>)
)
UNPIVOT used to set out into column values (that is, the column switch) in SQL Server 2000 can be used to achieve UNION
The complete syntax:
table_source
UNPIVOT(
value_column
FOR pivot_column
IN(<column_list>)
)
Note: PIVOT, UNPIVOT is SQL Server 2005 syntax, and is required to modify the database compatibility level of
the database Properties -> Options -> changed to compatibility level 90
IF object_id ( ' TB ' ) IS Not null drop Table TB Go Create Table TB (name VARCHAR ( 10 ), the course VARCHAR ( 10 ), the score int ) INSERT INTO TB values ( ' John Doe ' , ' language ' , 74 ) INSERT INTO TB values ( ' Joe Smith ' , ' Mathematics' , 83 ) INSERT INTO TB values ( ' John Doe ' , ' physical ' , 93 ) INSERT INTO TB values ( ' John Doe ' , ' language ' , 74 ) INSERT INTO TB values ( ' John Doe ' , ' mathematics ' , 84 ) INSERT INTO TB values ( 'John Doe ' , ' physical ' , 94 ) Go SELECT * from TB
method one:
The question now is: I want this person three statistical results by name, namely: the name of the language of mathematical physics
First look at using time case when end structure:
select name, max ( Case course the when ' language ' the then score the else 0 End ) language, max ( Case course the when ' mathematical ' the then score the else 0 End ) mathematics, max ( Case course the when ' physical ' the then score the else 0 End ) Physics from TB Group by name
Option two: pivot function
the SELECT * from TB Pivot ( max (score) for courses in (language, mathematics, physics)) a
Provided that the above query:
PIVOT, UNPIVOT is SQL Server 2005 syntax, and is required to modify the database compatibility level of
the database Properties -> Options -> changed to compatibility level 90
If you do not change the compatibility level 90, the query results are as follows:
