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SQL 서버에서 행을 열로 효율적으로 변환
SQL Server에서 행을 열로 효율적으로 변환하는 방법을 찾고 있는데, PIVOT가 그리 빠르지 않다고 들어서 많은 레코드를 처리해야 합니다.
다음은 예를 제시하겠습니다.
| 아이디 | 가치 | 컬럼명 |
|---|---|---|
| 1 | 존. | 이름 |
| 2 | 2.4 | 양 |
| 3 | ZH1E4A | 우편 번호 |
| 4 | 포크 | 성 |
| 5 | 857685 | 어카운트 번호 |
결과는 다음과 같습니다.
| 이름 | 양 | 우편 번호 | 성 | 어카운트 번호 |
|---|---|---|---|---|
| 존. | 2.4 | ZH1E4A | 포크 | 857685 |
어떻게 하면 결과를 만들 수 있을까요?
여러 행의 데이터를 열로 변환할 수 있는 방법은 여러 가지가 있습니다.
사용.PIVOT
SQL Server에서는PIVOT데이터를 행에서 열로 변환하는 함수:
select Firstname, Amount, PostalCode, LastName, AccountNumber
from
(
select value, columnname
from yourtable
) d
pivot
(
max(value)
for columnname in (Firstname, Amount, PostalCode, LastName, AccountNumber)
) piv;
데모를 참조해 주세요.
알 수 없는 수의 피벗columnnames
알 수 없는 번호가 있는 경우columnnames변환하고 싶은 경우 동적 SQL을 사용할 수 있습니다.
DECLARE @cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX)
select @cols = STUFF((SELECT ',' + QUOTENAME(ColumnName)
from yourtable
group by ColumnName, id
order by id
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = N'SELECT ' + @cols + N' from
(
select value, ColumnName
from yourtable
) x
pivot
(
max(value)
for ColumnName in (' + @cols + N')
) p '
exec sp_executesql @query;
데모를 참조해 주세요.
집계 함수 사용
를 사용하지 않을 경우PIVOT이 경우 집약 함수를 사용하여CASE식:
select
max(case when columnname = 'FirstName' then value end) Firstname,
max(case when columnname = 'Amount' then value end) Amount,
max(case when columnname = 'PostalCode' then value end) PostalCode,
max(case when columnname = 'LastName' then value end) LastName,
max(case when columnname = 'AccountNumber' then value end) AccountNumber
from yourtable
데모를 참조해 주세요.
여러 조인 사용
이 작업은 여러 조인을 사용하여 완료할 수도 있지만 샘플 데이터에 없는 각 행을 연결할 열이 필요합니다.그러나 기본 구문은 다음과 같습니다.
select fn.value as FirstName,
a.value as Amount,
pc.value as PostalCode,
ln.value as LastName,
an.value as AccountNumber
from yourtable fn
left join yourtable a
on fn.somecol = a.somecol
and a.columnname = 'Amount'
left join yourtable pc
on fn.somecol = pc.somecol
and pc.columnname = 'PostalCode'
left join yourtable ln
on fn.somecol = ln.somecol
and ln.columnname = 'LastName'
left join yourtable an
on fn.somecol = an.somecol
and an.columnname = 'AccountNumber'
where fn.columnname = 'Firstname'
이것은 단일 스크립트라기보다는 오히려 하나의 방식이지만 훨씬 더 유연합니다.
먼저 3가지 오브젝트가 있습니다.
- 사용자 정의 탭LE 타입 [
ColumnActionList] ->는 데이터를 파라미터로 유지합니다. - SP[
proc_PivotPrepare] -> 데이터 준비 - SP[
proc_PivotExecute] -> 스크립트를 실행합니다.
CREATE TYPE [dbo]를 선택합니다.[ColumnActionList] AS TABLE([ID] [smallint] NOT NULL, [ColumnName] nvarchar NOT NULL, [Action] nchar NOT NULL), GO
CREATE PROCEDURE [dbo].[proc_PivotPrepare]
(
@DB_Name nvarchar(128),
@TableName nvarchar(128)
)
AS
SELECT @DB_Name = ISNULL(@DB_Name,db_name())
DECLARE @SQL_Code nvarchar(max)
DECLARE @MyTab TABLE (ID smallint identity(1,1), [Column_Name] nvarchar(128), [Type] nchar(1), [Set Action SQL] nvarchar(max));
SELECT @SQL_Code = 'SELECT [<| SQL_Code |>] = '' '' '
+ 'UNION ALL '
+ 'SELECT ''----------------------------------------------------------------------------------------------------'' '
+ 'UNION ALL '
+ 'SELECT ''-----| Declare user defined type [ID] / [ColumnName] / [PivotAction] '' '
+ 'UNION ALL '
+ 'SELECT ''----------------------------------------------------------------------------------------------------'' '
+ 'UNION ALL '
+ 'SELECT ''DECLARE @ColumnListWithActions ColumnActionList;'''
+ 'UNION ALL '
+ 'SELECT ''----------------------------------------------------------------------------------------------------'' '
+ 'UNION ALL '
+ 'SELECT ''-----| Set [PivotAction] (''''S'''' as default) to select dimentions and values '' '
+ 'UNION ALL '
+ 'SELECT ''-----|'''
+ 'UNION ALL '
+ 'SELECT ''-----| ''''S'''' = Stable column || ''''D'''' = Dimention column || ''''V'''' = Value column '' '
+ 'UNION ALL '
+ 'SELECT ''----------------------------------------------------------------------------------------------------'' '
+ 'UNION ALL '
+ 'SELECT ''INSERT INTO @ColumnListWithActions VALUES ('' + CAST( ROW_NUMBER() OVER (ORDER BY [NAME]) as nvarchar(10)) + '', '' + '''''''' + [NAME] + ''''''''+ '', ''''S'''');'''
+ 'FROM [' + @DB_Name + '].sys.columns '
+ 'WHERE object_id = object_id(''[' + @DB_Name + ']..[' + @TableName + ']'') '
+ 'UNION ALL '
+ 'SELECT ''----------------------------------------------------------------------------------------------------'' '
+ 'UNION ALL '
+ 'SELECT ''-----| Execute sp_PivotExecute with parameters: columns and dimentions and main table name'' '
+ 'UNION ALL '
+ 'SELECT ''----------------------------------------------------------------------------------------------------'' '
+ 'UNION ALL '
+ 'SELECT ''EXEC [dbo].[sp_PivotExecute] @ColumnListWithActions, ' + '''''' + @TableName + '''''' + ';'''
+ 'UNION ALL '
+ 'SELECT ''----------------------------------------------------------------------------------------------------'' '
EXECUTE SP_EXECUTESQL @SQL_Code;
GO
CREATE PROCEDURE [dbo].[sp_PivotExecute]
(
@ColumnListWithActions ColumnActionList ReadOnly
,@TableName nvarchar(128)
)
AS
--#######################################################################################################################
--###| Step 1 - Select our user-defined-table-variable into temp table
--#######################################################################################################################
IF OBJECT_ID('tempdb.dbo.#ColumnListWithActions', 'U') IS NOT NULL DROP TABLE #ColumnListWithActions;
SELECT * INTO #ColumnListWithActions FROM @ColumnListWithActions;
--#######################################################################################################################
--###| Step 2 - Preparing lists of column groups as strings:
--#######################################################################################################################
DECLARE @ColumnName nvarchar(128)
DECLARE @Destiny nchar(1)
DECLARE @ListOfColumns_Stable nvarchar(max)
DECLARE @ListOfColumns_Dimension nvarchar(max)
DECLARE @ListOfColumns_Variable nvarchar(max)
--############################
--###| Cursor for List of Stable Columns
--############################
DECLARE ColumnListStringCreator_S CURSOR FOR
SELECT [ColumnName]
FROM #ColumnListWithActions
WHERE [Action] = 'S'
OPEN ColumnListStringCreator_S;
FETCH NEXT FROM ColumnListStringCreator_S
INTO @ColumnName
WHILE @@FETCH_STATUS = 0
BEGIN
SELECT @ListOfColumns_Stable = ISNULL(@ListOfColumns_Stable, '') + ' [' + @ColumnName + '] ,';
FETCH NEXT FROM ColumnListStringCreator_S INTO @ColumnName
END
CLOSE ColumnListStringCreator_S;
DEALLOCATE ColumnListStringCreator_S;
--############################
--###| Cursor for List of Dimension Columns
--############################
DECLARE ColumnListStringCreator_D CURSOR FOR
SELECT [ColumnName]
FROM #ColumnListWithActions
WHERE [Action] = 'D'
OPEN ColumnListStringCreator_D;
FETCH NEXT FROM ColumnListStringCreator_D
INTO @ColumnName
WHILE @@FETCH_STATUS = 0
BEGIN
SELECT @ListOfColumns_Dimension = ISNULL(@ListOfColumns_Dimension, '') + ' [' + @ColumnName + '] ,';
FETCH NEXT FROM ColumnListStringCreator_D INTO @ColumnName
END
CLOSE ColumnListStringCreator_D;
DEALLOCATE ColumnListStringCreator_D;
--############################
--###| Cursor for List of Variable Columns
--############################
DECLARE ColumnListStringCreator_V CURSOR FOR
SELECT [ColumnName]
FROM #ColumnListWithActions
WHERE [Action] = 'V'
OPEN ColumnListStringCreator_V;
FETCH NEXT FROM ColumnListStringCreator_V
INTO @ColumnName
WHILE @@FETCH_STATUS = 0
BEGIN
SELECT @ListOfColumns_Variable = ISNULL(@ListOfColumns_Variable, '') + ' [' + @ColumnName + '] ,';
FETCH NEXT FROM ColumnListStringCreator_V INTO @ColumnName
END
CLOSE ColumnListStringCreator_V;
DEALLOCATE ColumnListStringCreator_V;
SELECT @ListOfColumns_Variable = LEFT(@ListOfColumns_Variable, LEN(@ListOfColumns_Variable) - 1);
SELECT @ListOfColumns_Dimension = LEFT(@ListOfColumns_Dimension, LEN(@ListOfColumns_Dimension) - 1);
SELECT @ListOfColumns_Stable = LEFT(@ListOfColumns_Stable, LEN(@ListOfColumns_Stable) - 1);
--#######################################################################################################################
--###| Step 3 - Preparing table with all possible connections between Dimension columns excluding NULLs
--#######################################################################################################################
DECLARE @DIM_TAB TABLE ([DIM_ID] smallint, [ColumnName] nvarchar(128))
INSERT INTO @DIM_TAB
SELECT [DIM_ID] = ROW_NUMBER() OVER(ORDER BY [ColumnName]), [ColumnName] FROM #ColumnListWithActions WHERE [Action] = 'D';
DECLARE @DIM_ID smallint;
SELECT @DIM_ID = 1;
DECLARE @SQL_Dimentions nvarchar(max);
IF OBJECT_ID('tempdb.dbo.##ALL_Dimentions', 'U') IS NOT NULL DROP TABLE ##ALL_Dimentions;
SELECT @SQL_Dimentions = 'SELECT [xxx_ID_xxx] = ROW_NUMBER() OVER (ORDER BY ' + @ListOfColumns_Dimension + '), ' + @ListOfColumns_Dimension
+ ' INTO ##ALL_Dimentions '
+ ' FROM (SELECT DISTINCT' + @ListOfColumns_Dimension + ' FROM ' + @TableName
+ ' WHERE ' + (SELECT [ColumnName] FROM @DIM_TAB WHERE [DIM_ID] = @DIM_ID) + ' IS NOT NULL ';
SELECT @DIM_ID = @DIM_ID + 1;
WHILE @DIM_ID <= (SELECT MAX([DIM_ID]) FROM @DIM_TAB)
BEGIN
SELECT @SQL_Dimentions = @SQL_Dimentions + 'AND ' + (SELECT [ColumnName] FROM @DIM_TAB WHERE [DIM_ID] = @DIM_ID) + ' IS NOT NULL ';
SELECT @DIM_ID = @DIM_ID + 1;
END
SELECT @SQL_Dimentions = @SQL_Dimentions + ' )x';
EXECUTE SP_EXECUTESQL @SQL_Dimentions;
--#######################################################################################################################
--###| Step 4 - Preparing table with all possible connections between Stable columns excluding NULLs
--#######################################################################################################################
DECLARE @StabPos_TAB TABLE ([StabPos_ID] smallint, [ColumnName] nvarchar(128))
INSERT INTO @StabPos_TAB
SELECT [StabPos_ID] = ROW_NUMBER() OVER(ORDER BY [ColumnName]), [ColumnName] FROM #ColumnListWithActions WHERE [Action] = 'S';
DECLARE @StabPos_ID smallint;
SELECT @StabPos_ID = 1;
DECLARE @SQL_MainStableColumnTable nvarchar(max);
IF OBJECT_ID('tempdb.dbo.##ALL_StableColumns', 'U') IS NOT NULL DROP TABLE ##ALL_StableColumns;
SELECT @SQL_MainStableColumnTable = 'SELECT xxx_ID_xxx = ROW_NUMBER() OVER (ORDER BY ' + @ListOfColumns_Stable + '), ' + @ListOfColumns_Stable
+ ' INTO ##ALL_StableColumns '
+ ' FROM (SELECT DISTINCT' + @ListOfColumns_Stable + ' FROM ' + @TableName
+ ' WHERE ' + (SELECT [ColumnName] FROM @StabPos_TAB WHERE [StabPos_ID] = @StabPos_ID) + ' IS NOT NULL ';
SELECT @StabPos_ID = @StabPos_ID + 1;
WHILE @StabPos_ID <= (SELECT MAX([StabPos_ID]) FROM @StabPos_TAB)
BEGIN
SELECT @SQL_MainStableColumnTable = @SQL_MainStableColumnTable + 'AND ' + (SELECT [ColumnName] FROM @StabPos_TAB WHERE [StabPos_ID] = @StabPos_ID) + ' IS NOT NULL ';
SELECT @StabPos_ID = @StabPos_ID + 1;
END
SELECT @SQL_MainStableColumnTable = @SQL_MainStableColumnTable + ' )x';
EXECUTE SP_EXECUTESQL @SQL_MainStableColumnTable;
--#######################################################################################################################
--###| Step 5 - Preparing table with all options ID
--#######################################################################################################################
DECLARE @FULL_SQL_1 NVARCHAR(MAX)
SELECT @FULL_SQL_1 = ''
DECLARE @i smallint
IF OBJECT_ID('tempdb.dbo.##FinalTab', 'U') IS NOT NULL DROP TABLE ##FinalTab;
SELECT @FULL_SQL_1 = 'SELECT t.*, dim.[xxx_ID_xxx] '
+ ' INTO ##FinalTab '
+ 'FROM ' + @TableName + ' t '
+ 'JOIN ##ALL_Dimentions dim '
+ 'ON t.' + (SELECT [ColumnName] FROM @DIM_TAB WHERE [DIM_ID] = 1) + ' = dim.' + (SELECT [ColumnName] FROM @DIM_TAB WHERE [DIM_ID] = 1);
SELECT @i = 2
WHILE @i <= (SELECT MAX([DIM_ID]) FROM @DIM_TAB)
BEGIN
SELECT @FULL_SQL_1 = @FULL_SQL_1 + ' AND t.' + (SELECT [ColumnName] FROM @DIM_TAB WHERE [DIM_ID] = @i) + ' = dim.' + (SELECT [ColumnName] FROM @DIM_TAB WHERE [DIM_ID] = @i)
SELECT @i = @i +1
END
EXECUTE SP_EXECUTESQL @FULL_SQL_1
--#######################################################################################################################
--###| Step 6 - Selecting final data
--#######################################################################################################################
DECLARE @STAB_TAB TABLE ([STAB_ID] smallint, [ColumnName] nvarchar(128))
INSERT INTO @STAB_TAB
SELECT [STAB_ID] = ROW_NUMBER() OVER(ORDER BY [ColumnName]), [ColumnName]
FROM #ColumnListWithActions WHERE [Action] = 'S';
DECLARE @VAR_TAB TABLE ([VAR_ID] smallint, [ColumnName] nvarchar(128))
INSERT INTO @VAR_TAB
SELECT [VAR_ID] = ROW_NUMBER() OVER(ORDER BY [ColumnName]), [ColumnName]
FROM #ColumnListWithActions WHERE [Action] = 'V';
DECLARE @y smallint;
DECLARE @x smallint;
DECLARE @z smallint;
DECLARE @FinalCode nvarchar(max)
SELECT @FinalCode = ' SELECT ID1.*'
SELECT @y = 1
WHILE @y <= (SELECT MAX([xxx_ID_xxx]) FROM ##FinalTab)
BEGIN
SELECT @z = 1
WHILE @z <= (SELECT MAX([VAR_ID]) FROM @VAR_TAB)
BEGIN
SELECT @FinalCode = @FinalCode + ', [ID' + CAST((@y) as varchar(10)) + '.' + (SELECT [ColumnName] FROM @VAR_TAB WHERE [VAR_ID] = @z) + '] = ID' + CAST((@y + 1) as varchar(10)) + '.' + (SELECT [ColumnName] FROM @VAR_TAB WHERE [VAR_ID] = @z)
SELECT @z = @z + 1
END
SELECT @y = @y + 1
END
SELECT @FinalCode = @FinalCode +
' FROM ( SELECT * FROM ##ALL_StableColumns)ID1';
SELECT @y = 1
WHILE @y <= (SELECT MAX([xxx_ID_xxx]) FROM ##FinalTab)
BEGIN
SELECT @x = 1
SELECT @FinalCode = @FinalCode
+ ' LEFT JOIN (SELECT ' + @ListOfColumns_Stable + ' , ' + @ListOfColumns_Variable
+ ' FROM ##FinalTab WHERE [xxx_ID_xxx] = '
+ CAST(@y as varchar(10)) + ' )ID' + CAST((@y + 1) as varchar(10))
+ ' ON 1 = 1'
WHILE @x <= (SELECT MAX([STAB_ID]) FROM @STAB_TAB)
BEGIN
SELECT @FinalCode = @FinalCode + ' AND ID1.' + (SELECT [ColumnName] FROM @STAB_TAB WHERE [STAB_ID] = @x) + ' = ID' + CAST((@y+1) as varchar(10)) + '.' + (SELECT [ColumnName] FROM @STAB_TAB WHERE [STAB_ID] = @x)
SELECT @x = @x +1
END
SELECT @y = @y + 1
END
SELECT * FROM ##ALL_Dimentions;
EXECUTE SP_EXECUTESQL @FinalCode;
첫 번째 쿼리 실행(소스 DB 및 테이블 이름 전달)에서 두 번째 SP에 대해 미리 작성된 실행 쿼리를 가져옵니다.필요한 것은 소스의 컬럼입니다.+ Stable + Value (그 값을 바탕으로 값을 집중시키는 데 사용됨)+ Dim (피벗에 사용하는 컬럼)
이름과 데이터 유형이 자동으로 정의됩니다!
어떤 프로덕션 환경에서도 추천할 수 없지만 애드혹 BI 요청에 대해서는 작업을 수행합니다.
Taryn의 답변('컬럼 이름 수를 알 수 없는 피봇' 버전)을 수정하여 결과에 두 개 이상의 행이 표시되도록 했습니다.여기에는 추가 "그룹" 열이 필요합니다.
DROP TABLE #yourtable
CREATE table #yourtable
([Id] int,[Group] int, [Value] varchar(6), [ColumnName] varchar(13))
;
INSERT INTO #yourtable
([Id],[Group], [Value], [ColumnName])
VALUES
(1,1, 'John', 'FirstName'),
(2,1, '2.4', 'Amount'),
(3,1, 'ZH1E4A', 'PostalCode'),
(4,1, 'Fork', 'LastName'),
(5,1, '857685', 'AccountNumber'),
(6,2, 'Pedro', 'FirstName'),
(7,2, '5.1', 'Amount'),
(8,2, '123456', 'PostalCode'),
(9,2, 'Torres', 'LastName'),
(10,2, '857686', 'AccountNumber')
;
;
DECLARE @cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX)
select @cols = STUFF((SELECT ',' + QUOTENAME(ColumnName)
from #yourtable
group by [Group], ColumnName, id
having [group] = (SELECT TOP 1 MIN([Group])FROM #yourtable)
order by id
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = N'SELECT ' + @cols + N' from
(
select value, ColumnName,[Group]
from #yourtable
GROUP BY [Group],ColumnName,Value
) x
pivot
(
max(value)
for ColumnName in (' + @cols + N')
) p '
exec sp_executesql @query;
매우 유용할 수 있는 또 하나의 옵션은 CROSS APPLY를 사용하는 것입니다.
-- Original data
SELECT * FROM (VALUES ('1', 1, 2, 3),('2', 11, 22, 33)) AS Stage(id,col1,col2,col3)
-- row to columns using CROSS APPLY
SELECT Stage.id,v.idd, v.colc
FROM (VALUES ('1', 1, 2, 3),('2', 11, 22, 33)) AS Stage(id,col1,col2,col3)
CROSS APPLY (VALUES ('col1', col1),('col2', col2),('col3', col3)) AS v(idd,colc)
GO
시도해 보세요
CREATE TABLE pvt (Present int, [Absent] int);
GO
INSERT INTO pvt VALUES (10,40);
GO
--Unpivot the table.
SELECT Code, Value
FROM
(SELECT Present, Absent
FROM pvt) p
UNPIVOT
(Value FOR Code IN
(Present, [Absent])
)AS unpvt;
GO
DROP TABLE pvt
언급URL : https://stackoverflow.com/questions/15745042/efficiently-convert-rows-to-columns-in-sql-server
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