Pivot is used to rotate column values to column names (row to column), and SQL Server 2000 can be implemented with an aggregate function with a case statement
The general syntax for pivot is: Pivot (aggregate function (column) for column in (...)) As P
Full syntax:
Table_source
PIVOT (
Aggregation function (value_column)
For Pivot_column
In (<column_list>)
)
Unpivot is used to convert columns to column values (that is, column change), which can be implemented with union in SQL Server 2000
Full syntax:
Table_source
UNPIVOT (
Value_column
For Pivot_column
In (<column_list>)
)
Note: PIVOT, Unpivot is the syntax for SQL Server 2005 , use the database compatibility level that you want to modify
In the database properties, options, compatibility level, change to 90
Typical examples
First, row to column
1. Create a form
ifobject_id (' TB ') ISNOTNULLDROPTABLETB
Go
CREATETABLETB (name varchar (10), course varchar (10), fractional int)
Insertintotbvalues (' Zhang San ', ' language ', 74)
Insertintotbvalues (' Zhang San ', ' mathematics ', 83)
Insertintotbvalues (' Zhang San ', ' physics ', 93)
Insertintotbvalues (' John Doe ', ' language ', 74)
Insertintotbvalues (' John Doe ', ' mathematics ', 84)
Insertintotbvalues (' John Doe ', ' physics ', 94)
Go
Select*fromtb
Go
Name Course Score
---------- ---------- -----------
Zhang San language 74
Zhang San Mathematics 83
Zhang San Physics 93
John Doe Language 74
John Doe Mathematics 84
John Doe Physics 94
2. Using SQL Server 2000 static SQL
--c
Select Name,
Max (case course when ' language ' then score else0end) language,
Max (case course when ' math ' then fraction else0end) Math,
Max (case course when ' physical ' then fraction else0end) Physics
Fromtb
GroupBy Name
Name Chinese mathematics Physics
---------- ----------- ----------- -----------
Lee 474 84 94
Sheet 374 83 93
3. Using SQL Server 2000 dynamic SQL
--sql SERVER 2000 Dynamic SQL, refers to the course of more than language, mathematics, physics, this course. (hereinafter)
--variables are assigned in SQL language order
[Email protected] (500)
[Email protected]= ' Select name '
[Email protected] [Email protected]+ ', max (case course when "+ Course +" then score else 0 end) [' + Course + '] '
From (selectdistinct course FROMTB) a--with from TB Group by course, sorted by course name by default
[Email protected] [Email protected]+ ' from TB Group by name '
EXEC (@sql)
--Using IsNull (), variables determine the dynamic part first
[Email protected] (8000)
[Email protected]=isnull (@sql + ', ', ') + ' max (case course when ' + course + ' then score else 0 end) [' + Course + '] '
From (selectdistinct course FROMTB) ASA
[Email protected]= ' Select name, ' [email protected]+ ' from TB Group by name '
EXEC (@sql)
Name Mathematical Physics language
---------- ----------- ----------- -----------
Lee 484 94 74
Sheet 383 93 74
4. Using SQL Server 2005 static SQL
SELECT*FROMTB Pivot (max (score) for course in (language, mathematics, physics)) a
5. Using SQL Server 2005 Dynamic SQL
--Using stuff ()
[Email protected] (8000)
[Email protected]= '--Initialize variable @sql
[Email protected] [Email protected]+ ', ' + Course fromtbgroupby Course--Variable multi-value assignment
[Email Protected]=stuff (@sql, 1, 1, ')--Remove the first ', '
[Email protected]= ' SELECT * from TB pivot (MAX (score) for course in (' [email protected]+ ')) ' a '
EXEC (@sql)
--or use ISNULL ()
[Email protected] (8000)
–-get a collection of courses
[Email protected]=isnull (@sql + ', ', ') + Course Fromtbgroupby Course
[Email protected]= ' SELECT * from TB pivot (MAX (score) for course in (' [email protected]+ ')) ' a '
EXEC (@sql)
The results of the row and column are combined with the total score, the average
1. Using SQL Server 2000 static SQL
--sql SERVER 2000 Static SQL
Select Name,
Max (case course when ' language ' then score else0end) language,
Max (case course when ' math ' then fraction else0end) Math,
Max (case course when ' physical ' then fraction else0end) Physics,
SUM (Score) Total,
Average of CAST (avg (fractional *1.0) Asdecimal (18,2))
Fromtb
GroupBy Name
The average score of the mathematics physics of the name Chinese
---------- ----------- ----------- ----------- -----------
Lee 474 84 94 252 84.00
Sheet 374 83 93 250 83.33
2. Using SQL Server 2000 dynamic SQL
--sql SERVER 2000 Dynamic SQL
[Email protected] (500)
[Email protected]= ' Select name '
[Email protected] [Email protected]+ ', max (case course when "+ Course +" then score else 0 end) [' + Course + '] '
From (selectdistinct course FROMTB) A
[Email protected] [Email protected]+ ', sum (score) Total, cast (avg (fractional *1.0) as decimal (18,2)) average from TB group by name '
EXEC (@sql)
3. Using SQL Server 2005 static SQL
Selectm.*,n. Total score, N. Average
From
(SELECT*FROMTB pivot (max (score) for course in (language, mathematics, physics)) m,
(select name, sum (score) Total, cast (AVG (score *1.0) Asdecimal (18,2)) Average score
Fromtb
GroupBy name) n
Wherem. Name =n. Name
4. Using SQL Server 2005 Dynamic SQL
--Using stuff ()
--
[Email protected] (8000)
[Email protected]= '--Initialize variable @sql
[Email protected] [Email protected]+ ', ' + Course fromtbgroupby Course--Variable multi-value assignment
--with Select @sql = @sql + ', ' + course from (SELECT DISTINCT course from TB) a
[Email Protected]=stuff (@sql, 1, 1, ')--Remove the first ', '
[Email protected]= ' Select m.*, N. Total score, N. Average from
(SELECT * FROM (SELECT * from TB) a pivot (max (score) for course in (' [email protected]+ ')) b) m,
(select name, sum (score) Total, cast (avg (fractional *1.0) as decimal (18,2)), average of the from TB Group by name) n
where M. Name = N. Name '
EXEC (@sql)
--or use ISNULL ()
[Email protected] (8000)
[Email protected]=isnull (@sql + ', ', ') + Course Fromtbgroupby Course
[Email protected]= ' Select m.*, N. Total score, N. Average from
(SELECT * FROM (SELECT * from TB) a pivot (max (score) for course in (' +
@sql + ')) b) m,
(select name, sum (score) Total, cast (avg (fractional *1.0) as decimal (18,2)), average of the from TB Group by name) n
where M. Name = N. Name '
EXEC (@sql)
Second, the list of career change
1. Create a form
ifobject_id (' TB ') ISNOTNULLDROPTABLETB
Go
CREATETABLETB (name varchar (10), language int, math int, physical int)
Insertintotbvalues (' Zhang San ', 74,83,93)
Insertintotbvalues (' John Doe ', 74,84,94)
Go
Select*fromtb
Go
Name Chinese mathematics Physics
---------- ----------- ----------- -----------
Sheet 374 83 93
Lee 474 84 94
2. Using SQL Server 2000 static SQL
--sql SERVER 2000 Static SQL.
Select*from
(
Select name, course = ' language ', score = Chinese FROMTB
UnionAll
Select name, course = ' math ', score = Math FROMTB
UnionAll
Select name, course = ' physical ', score = physical FROMTB
) T
By name, case course when ' language ' then1when ' math ' then2when ' physical ' then3End
Name Course Score
---------- ---- -----------
John Doe Language 74
John Doe Mathematics 84
John Doe Physics 94
Zhang San language 74
Zhang San Mathematics 83
Zhang San Physics 93
2. Using SQL Server 2000 dynamic SQL
--sql SERVER 2000 Dynamic SQL.
--Call system table dynamic Ecology.
[Email protected] (8000)
[Email protected]=isnull (@sql + ' union All ', ') + ' select name, [Course]= '
+quotename (Name, "') + ', [score] = ' +quotename (name) + ' from TB '
Fromsyscolumns
wherename!= ' name ' andid=object_id (' TB ')--table name TB, not including other columns named name
Orderbycolid
EXEC (@sql + ' ORDER by name ')
Go
3. Using SQL Server 2005 static SQL
--sql SERVER 2005 Dynamic SQL
Select Name, course, score fromtb Unpivot (score for course in ([Language],[Math],[physics]) t
4. Using SQL Server 2005 Dynamic SQL
--sql SERVER 2005 Dynamic SQL
[Email protected] (4000)
[Email protected]=isnull (@sql + ', ', ') +quotename (Name)
Fromsyscolumns
whereid=object_id (' TB ') andnamenotin (' name ')
Orderbycolid
[Email protected]= ' Select name, [Course],[score] from TB Unpivot ([score] for [course] in (' [email protected]+ ')] B '
EXEC (@sql)