Question

我的桌子很动态。 E.g：

id      SUBJECT
1   his
2   math
3   sci
4   opt
5   ENG
6   SOC

行数不受限制。可能有一百个。我想要这样的输出：

ID 1     2     3      4     5      6  

   HIS  MATH    SCI   OPT   ENG   SOC

我可以使用数据透视查询，但我必须知道列数。如何在不事先知道列数的情况下执行此操作？

Answer 1

我得到了答案，但这很棘手

为您的所有记录创建一个表格
计算记录
创建一个包含大量列的表
为包含记录的表创建逗号分隔变量
然后将逗号分隔的变量拆分为多个列

这是代码

DECLARE  @HEADDESC NVARCHAR(150)
DROP TABLE #HEADS
CREATE TABLE #HEADS
(
    ID INT IDENTITY
   ,HEADS NVARCHAR(150)
   ,NU INT 
)
DECLARE @NO INT;
SET @NO = 0
DECLARE C1 CURSOR FOR (
    SELECT  HEADDESC 
    FROM GMC.FEEHEAD_MASTER 
    WHERE CODE = 'GF' AND HEADDESC <> '')
OPEN C1
FETCH NEXT FROM C1 INTO @HEADDESC

WHILE @@FETCH_STATUS  = 0
BEGIN
    PRINT @HEADDESC
    SET @NO = @NO+1 
    INSERT INTO #HEADS(HEADS,NU) 
    VALUES(@HEADDESC,@NO)

    FETCH NEXT FROM C1 INTO @HEADDESC
END
--SELECT * FROM #HEADS
CLOSE C1
DEALLOCATE C1
DECLARE @COLNO INT

SET @COLNO = (SELECT COUNT(*) FROM #HEADS)

DECLARE @COLUMNS VARCHAR(8000)

SELECT @COLUMNS = COALESCE(@COLUMNS +','+  CAST(HEADS AS VARCHAR) ,
       CAST(HEADS AS VARCHAR))
FROM #HEADS
--GROUP BY HEADS

DECLARE @value NVARCHAR(100)

SET @value = ',1,STUDENTIDNO,STUDENTNAME,'

SET @COLUMNS = @VALUE+@COLUMNS
SET @COLNO = @COLNO+4
--SELECT @COLUMNS
DROP TABLE  #HEADSCOMMA
CREATE TABLE #HEADSCOMMA(HEADS NVARCHAR(3000))

INSERT INTO  #HEADSCOMMA VALUES (@COLUMNS)

DROP TABLE #TEMP
CREATE TABLE #TEMP(COL1 NVARCHAR(1000))
DECLARE @SQL NVARCHAR(MAX)
DECLARE @COL NVARCHAR(1000)
DECLARE @COL1 INT
DECLARE @COLNAME NVARCHAR(1000)

SET  @COL1 = 2
SET @COL = 'COL'
PRINT @COL1
--SET @COLNAME = @COL +CAST(@COL1 AS NVARCHAR(10))

WHILE @COL1 < =@COLNO
BEGIN
    SET @COLNAME = @COL +CAST(@COL1 AS NVARCHAR(100))
    PRINT @COLNAME
    SET @SQL = 'ALTER TABLE #TEMP ADD '+@COLNAME+' NVARCHAR(100)'
    EXEC(@SQL)
    SET @COL1= @COL1+1
END


--SELECT * FROM #HEADSCOMMA -- COMMA SEPERATED VALUES
DECLARE @S VARCHAR(8000), @DATA VARCHAR(8000)
--DROP TABLE  #NORMALISEDTABLE
--CREATE TABLE #NORMALISEDTABLE (HEADS NVARCHAR(200))
SELECT @S=''

WHILE EXISTS (SELECT * FROM #HEADSCOMMA WHERE HEADS>@S)
BEGIN
    SELECT @S=HEADS FROM #HEADSCOMMA WHERE HEADS>@S
    PRINT @S
    SELECT @DATA=''''+REPLACE(@S,',',''',''')+''''
    PRINT @DATA
    INSERT INTO #TEMP
    EXEC('SELECT '+@DATA)
END

SELECT * FROM #temp

将提供记录

Answer 2

动态SQL是一种选择。

透过SQL Server 2005获取未知行数

2 个答案: