sql server行转列（pivot），列转行（unpivot）

说明

可以使用 PIVOT 和 UNPIVOT 关系运算符将表值表达式更改为另一个表。 PIVOT 通过将表达式中的一个列的唯一值转换为输出中的多列，来轮替表值表达式。 PIVOT 在需要对最终输出所需的所有剩余列值执行聚合时运行聚合。 与 PIVOT 执行的操作相反，UNPIVOT 将表值表达式的列轮换为列值。
PIVOT 提供的语法比一系列复杂的 SELECT…CASE 语句中所指定的语法更简单和更具可读性。

语法

SELECT <non-pivoted column>,      [first pivoted column] AS <column name>,      [second pivoted column] AS <column name>,      ...      [last pivoted column] AS <column name>  FROM      (<SELECT query that produces the data>)       AS <alias for the source query>  PIVOT  (      <aggregation function>(<column being aggregated>)  FOR   [<column that contains the values that will become column headers>]       IN ( [first pivoted column], [second pivoted column],      ... [last pivoted column])  ) AS <alias for the pivot table>  <optional ORDER BY clause>;

PIVOT （行转列）

create table #person(id int,num int)insert into #person values(1,157)insert into #person values(2,182)insert into #person values(3,175)insert into #person values(4,165)insert into #person values(5,178)select *from #personselect '身高'as highs ,[1],[2],[3],[4],[5] from (select id,num from #person) s pivot (avg(num)foR id in([1],[2],[3],[4],[5])  ) as p

原表

id  num1   1572   1823   1754   1655   178

pivot 后

highs   1   2   3   4   5身高  157 182 175 165 178

列转行（unpivot）

CREATE TABLE pvt (VendorID INT, Emp1 INT, Emp2 INT,      Emp3 INT, Emp4 INT, Emp5 INT);  GO  INSERT INTO pvt VALUES (1,4,3,5,4,4);  INSERT INTO pvt VALUES (2,4,1,5,5,5);  INSERT INTO pvt VALUES (3,4,3,5,4,4);  INSERT INTO pvt VALUES (4,4,2,5,5,4);  INSERT INTO pvt VALUES (5,5,1,5,5,5);  GO  select *from pvtSELECT VendorID, Employee, Orders  FROM      (SELECT VendorID, Emp1, Emp2, Emp3, Emp4, Emp5     FROM pvt) p  UNPIVOT     (Orders FOR Employee IN         (Emp1, Emp2, Emp3, Emp4, Emp5)  )AS unpvt;  GO  

原表

VendorID    Emp1    Emp2    Emp3    Emp4    Emp51   4   3   5   4   42   4   1   5   5   53   4   3   5   4   44   4   2   5   5   45   5   1   5   5   5

unpivot 后

VendorID    Employee    Orders1   Emp1    41   Emp2    31   Emp3    51   Emp4    41   Emp5    42   Emp1    42   Emp2    12   Emp3    52   Emp4    52   Emp5    53   Emp1    43   Emp2    33   Emp3    53   Emp4    43   Emp5    44   Emp1    44   Emp2    24   Emp3    54   Emp4    54   Emp5    45   Emp1    55   Emp2    15   Emp3    55   Emp4    55   Emp5    5

作者：浊尘

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