1. 介紹說明
前段時間組內的小伙伴在升級維護項目中，經常涉及一些復雜的數據轉換問題，讓我去看下有些地方怎么處理，我發現好多都是涉及到行列轉換的問題，處理起來經常會比較麻煩，借此也總結一下，方便以后的查閱使用。該總結參照了網上的一些資料，也做了一些變動，如有更好的方法也歡迎指出。
演示的腳本見 3.測試數據腳本
2. 例子演示
2.1 實現行轉列
(1) Case WHEN 實現行轉列
/*-----1.1 Case WHEN 實現行轉列----------*/ --(1)靜態SQL SELECT [姓名], max(CASE 課程 WHEN '語文' THEN 分數 ELSE 0 end) AS 語文, max(CASE 課程 WHEN '數學' THEN 分數 ELSE 0 end)AS 數學, max(CASE 課程 WHEN '物理' THEN 分數 ELSE 0 end)AS 物理, SUM(分數) AS 總分, AVG(分數) AS 平均分 FROM tbScore GROUP BY [姓名] --(2)動態SQL DECLARE @sql VARCHAR(500) SET @sql = 'SELECT [姓名]' SELECT @sql = @sql + ',MAX(CASE [課程] WHEN ''' + [課程] + ''' THEN [分數] ELSE 0 END)[' + [課程] + ']' FROM ( SELECT DISTINCT [課程] FROM tbScore ) T1 --同FROM tbScore GROUP BY [課程]，默認按課程名排序 SET @sql = @sql + ' FROM tbScore GROUP BY [姓名]' PRINT '@sql: ' + @sql EXEC(@sql)
(2) PIVOT 實現行轉列，其中的NULL值發現還不好處理為0
--(1)靜態SQL SELECT [姓名] , [語文] , [數學] , [物理] FROM ( SELECT [分數] , [課程] , [姓名] FROM tbScore ) AS SourceTable PIVOT ( AVG([分數]) FOR [課程] IN ( 語文, 數學, 物理 ) ) T --(2)動態SQL DECLARE @sql2 VARCHAR(8000) SET @sql2 = '' SELECT @sql2 = @sql2 + ',' + [課程] FROM dbo.tbScore GROUP BY [課程] --STUFF： 刪除指定長度的字符，並在指定的起點處插入另一組字符。 SET @sql2= STUFF(@sql2,1,1,'') --去掉首個',' SET @sql2 = 'SELECT [姓名],' + @sql2 + ' FROM (SELECT [分數],[課程],[姓名] FROM tbScore ) AS SourceTable PIVOT ( AVG([分數]) FOR [課程] IN ( ' + @sql2 + ') ) T' PRINT @sql2 EXEC(@sql2)
2.1 實現列轉行
(1) UNION 實現列轉行
--(1)靜態SQL SELECT * FROM ( SELECT [姓名],'語文' AS 課程,[語文] AS 分數 ,[日期] FROM tbScoreNew UNION ALL SELECT [姓名],'數學' AS 課程,[數學] AS 分數 ,[日期] FROM tbScoreNew UNION ALL SELECT [姓名],'物理' AS 課程,[物理] AS 分數 ,[日期] FROM tbScoreNew ) T ORDER BY [姓名] --(2)動態SQL DECLARE @sql3 VARCHAR(8000) SELECT @sql3 = ISNULL(@sql3 + ' UNION ALL ','') + ' SELECT [姓名],' + QUOTENAME(name,'''') + ' AS 課程,' + QUOTENAME(name) + ',[日期] FROM tbScoreNew' FROM sys.columns WHERE object_id = OBJECT_ID('tbScoreNew') AND name NOT IN ('姓名','日期') SET @sql3 = 'SELECT * FROM ( ' + @sql3 + ' ) T ORDER BY [姓名]' PRINT @sql3 EXEC (@sql3)
(2) UNPIVOT 實現列轉行
--(1)靜態SQL SELECT * FROM ( SELECT [姓名],[日期],[語文],[數學],[物理] FROM dbo.tbScoreNew ) T UNPIVOT ([分數] FOR [課程] IN ([語文],[數學],[物理])) T2 ORDER BY [姓名] --(2)動態SQL DECLARE @sql4 VARCHAR(8000) SELECT @sql4 = ISNULL(@sql4 + ',','') + QUOTENAME(name) FROM sys.columns WHERE object_id = OBJECT_ID('tbScoreNew') AND name NOT IN ('姓名','日期') SET @sql4 = 'SELECT * FROM ( SELECT [姓名],[日期],' + @sql4 + ' FROM dbo.tbScoreNew ) T UNPIVOT ([分數] FOR [課程] IN ('+ @sql4 +')) T2 ORDER BY [姓名]' PRINT @sql4 EXEC (@sql4)
2.3 動態增加列實現行轉列
這個參照部門小伙伴的項目上的要求寫的一個例子， 由於涉及的轉換列同時有多個字段，用上面的行列轉換處理起來都很不方便，所以采用比較普通的動態增加列的方式處理
測試數據腳本為附件腳本中的 “3.動態增加列實現行轉列" 腳本
要求: 將【部門預算】、【實際預算】、【剩余預算】按照年份橫向統計顯示，且統計數據按部門、項目分組顯示
CREATE TABLE #tmpYear ( [YEAR] INT, ID INT IDENTITY ) --保存最終結果 CREATE TABLE #tmpResult ( ID INT IDENTITY, DeptCode VARCHAR(20),--部門編碼 DeptName NVARCHAR(100), --部門名稱 ProCode VARCHAR(20),--項目編碼 ProName NVARCHAR(100),--項目名稱 KeyCode VARCHAR(50) ) GO --1.寫入分組數據 INSERT INTO #tmpResult( DeptCode ,DeptName , ProCode ,ProName,KeyCode) SELECT DeptCode,MAX(DeptName), ProCode,MAX(ProName),DeptCode + '_' + ProCode FROM tbDeptBudget GROUP BY DeptCode,ProCode --2.計算預算結果數據 --寫入年份數據 INSERT INTO #tmpYear SELECT DISTINCT Year FROM dbo.tbDeptBudget DECLARE @SQL VARCHAR(5000) DECLARE @ColName1 VARCHAR(50) DECLARE @ColName2 VARCHAR(50) DECLARE @ColName3 VARCHAR(50) DECLARE @Year INT DECLARE @ID INT DECLARE @RowNum INT SET @Year = 0 SET @ID = 1 SET @RowNum = (SELECT COUNT(0) FROM #tmpYear) WHILE @ID <= @RowNum BEGIN SET @Year = (SELECT [YEAR] FROM #tmpYear WHERE ID = @ID) SET @ColName1 = 'Bduget_' + CAST(@Year AS VARCHAR(10)) SET @ColName2 = 'Fact_' + CAST(@Year AS VARCHAR(10)) SET @ColName3 = 'Remain_' + CAST(@Year AS VARCHAR(10)) --增加動態列 SET @SQL = 'ALTER TABLE #tmpResult ADD ' + @ColName1 + ' Decimal(18,2)' + 'ALTER TABLE #tmpResult ADD ' + @ColName2 + ' Decimal(18,2)' + 'ALTER TABLE #tmpResult ADD ' + @ColName3 + ' Decimal(18,2)' EXEC(@SQL) --寫入動態列數據 SET @SQL = 'UPDATE T SET ' + @ColName1 + ' = S.BudgetAmount,' + @ColName2 + ' = S.FactAmount,'+ @ColName3 + ' = S.RemainAmount ' + ' FROM #tmpResult T INNER JOIN ( ' + ' SELECT (DeptCode + ' + QUOTENAME('_','''') +' + ProCode) AS KeyCode,MAX(BudgetAmount)AS BudgetAmount ,MAX(FactAmount)AS FactAmount,MAX(RemainAmount)AS RemainAmount ' + ' FROM dbo.tbDeptBudget WHERE Year= ' + CAST (@Year AS VARCHAR(10)) + ' GROUP BY DeptCode,ProCode ' + ') S ON T.KeyCode = S.KeyCode ' PRINT @SQL EXEC(@SQL) SET @ID = @ID + 1 END --3.返回結果 SELECT * FROM #tmpResult --4.清理臨時表 IF OBJECT_ID('tempdb..#tmpYear') IS NOT NULL BEGIN DROP TABLE #tmpYear END IF OBJECT_ID('tempdb..#tmpResult') IS NOT NULL BEGIN DROP TABLE #tmpResult END
3. 測試數據腳本
/*-----1.行轉列的測試數據--------------------------*/ IF OBJECT_ID('tbScore') IS NOT NULL DROP TABLE tbScore GO CREATE TABLE tbScore ( 姓名 VARCHAR(10) , 課程 VARCHAR(10) , 分數 INT, 日期 DATETIME ) GO INSERT INTO tbScore VALUES ( '張三', '語文', 74,GETDATE() ) --INSERT INTO tbScore VALUES ( '張三', '數學', 83 ,GETDATE() ) INSERT INTO tbScore VALUES ( '張三', '物理', 93 ,GETDATE() ) INSERT INTO tbScore VALUES ( '李四', '語文', 74 ,GETDATE() ) INSERT INTO tbScore VALUES ( '李四', '數學', 84 ,GETDATE() ) INSERT INTO tbScore VALUES ( '李四', '物理', 94 ,GETDATE() ) GO /*-----2.列轉行的測試數據--------------------------*/ IF OBJECT_ID('tbScoreNew') IS NOT NULL DROP TABLE tbScoreNew GO CREATE TABLE tbScoreNew( 姓名 VARCHAR(10) , 語文 INT, 數學 INT, 物理 INT, 日期 DATETIME ) GO INSERT INTO tbScoreNew VALUES ( '李四', 74,84,94,GETDATE() ) INSERT INTO tbScoreNew VALUES ( '張三', 74,83,93,GETDATE() ) GO /*-----3.動態增加列實現行轉列(模擬組內項目要求)--------------------------*/ IF OBJECT_ID('tbDeptBudget') IS NOT NULL DROP TABLE tbDeptBudget GO --部門預算 CREATE TABLE tbDeptBudget ( ID INT IDENTITY(1,1) PRIMARY KEY, DeptCode VARCHAR(20),--部門編碼 DeptName NVARCHAR(100), --部門名稱 ProCode VARCHAR(20),--項目編碼 ProName NVARCHAR(100),--項目名稱 Year INT, --年度 BudgetAmount DECIMAL(18,2), --預算金額 FactAmount DECIMAL(18,2), --實際金額 RemainAmount DECIMAL(18,2), --剩余金額 CreateTime DATETIME --創建時間 ) GO INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('人事部','010000','01','差旅費',2014,100000.00,80000.00,20000.00,GETDATE()); INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('人事部','010000','01','差旅費',2015,110000.00,90000.00,50000.00,GETDATE()); INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('人事部','010000','01','差旅費',2016,120000.00,100000.00,80000.00,GETDATE()); INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('人事部','010000','02','辦公用品',2015,200000.00,150000.00,10000.00,GETDATE()); INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('人事部','010000','02','辦公用品',2016,160000.00,120000.00,80000.00,GETDATE()); INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('財務部','020000','02','辦公用品',2014,50000.00,40000.00,0.00,GETDATE()); INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('財務部','020000','02','辦公用品',2015,50000.00,50000.00,10000.00,GETDATE()); INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('財務部','020000','02','辦公用品',2016,60000.00,50000.00,40000.00,GETDATE()); INSERT INTO tbDeptBudget(DeptName,DeptCode,ProCode,ProName,YEAR,BudgetAmount,FactAmount,RemainAmount,CreateTime) VALUES('財務部','020000','03','采購費',2016,100000.00,80000.00,60000.00,GETDATE());
4. 參考資料
http://www.cnblogs.com/zhangzt/archive/2010/07/29/1787825.html
http://www.cnblogs.com/gaizai/p/3753296.html