我已经提供了进入一个立方体,需要知道,如果我可以设置(通过MDX查询)的存储过程可以连接到多维数据集并检索内容。 我想这能防止不必将数据从Management Studio或从Excel(通过PowerPivot的)出口。 我很新的多维数据集/ OLAP查询所以请原谅所有的天真我可能会显示。
Answer 1:
最简单的方法是创建一个链接的服务器,以多维数据集,然后从INSERT..SELECT OPENQUERY http://sqlblog.com/blogs/stacia_misner/archive/2010/11/30/31193.aspx
此选项有其局限性,
- 它对MDX查询的8000字符限制
- 您必须手动创建链接的服务器为每个数据库
- 特殊的代码需要处理时,结果为空
- 在结果集中的列过多的数据类型(NTEXT用于列和nvarchar(4000)为行)
高级选项是ExecuteOLAP CLR存储过程https://olapextensions.codeplex.com/
Answer 2:
如果您选择使用OPENQUERY(最简单的方法,但有由Brian规定的限制),下面的过程可能会派上用场:
/*
PARAMS:
@mdx: mdx statement
@mdx_columns: specifies the mdx columns to retrieve from the executed mdx
@linkedServer: linked server to be used
@resultsTable: temporary table to hold results from mdx
@resultsCols: if only some columns should be filled in @resultsTable, specify them here (e.g. '(col1, col2, ... )' )
@expectedColCount: expected column count for mdx result. If actual column count is different from the expected count, no data is filled in
@actualColCount: actual column count. Specify NULL if not interesed in this value
@Debug: outputs debug info
*/
ALTER PROCEDURE [dbo].[exec_mdx_over_linked_server] (
@mdx NVARCHAR(MAX),
@mdx_columns NVARCHAR(1024) = '*',
@linkedServer VARCHAR(64),
@resultsTable VARCHAR(64),
@resultsCols VARCHAR(1024) = '',
@expectedColCount SMALLINT,
@actualColCount SMALLINT = NULL OUTPUT,
@Debug BIT = 0
)
AS
BEGIN
SET NOCOUNT ON
if (@Debug = 1)
PRINT 'Started exec_mdx_over_linked_server procedure for populating ' + @resultsTable
IF LEN(@MDX)>8000 RAISERROR ('MDX too long for openquery (exec_mdx_over_linked_server)',
16,
1);
declare @SQL NVARCHAR(MAX)
IF (@Debug = 1)
BEGIN
-- getting results from mdx
SET @SQL = 'SELECT ''Mdx results for ' + @resultsTable + ''' AS ''Mdx results'', ' + '*' + '
FROM OPENQUERY(' + @linkedServer + ', ''' + @mdx + ''')';
IF LEN(@SQL)>8000 RAISERROR ('MDX too long for openquery (exec_mdx_over_linked_server)',
16,
1);
EXEC (@SQL)
END
SET @SQL = '
SELECT ' + '*' + ' INTO #resultsWithWeirdNameToAvoidTempCollisions
FROM OPENQUERY(' + @linkedServer + ', ''' + @mdx + ''');
SELECT @colCount = COUNT(*)
FROM tempdb.sys.columns
WHERE object_id = object_id(''tempdb..#resultsWithWeirdNameToAvoidTempCollisions'');
if (@colCount = @expectedColCount)
INSERT INTO ' + @resultsTable + @resultsCols + '
SELECT ' + @mdx_columns + ' FROM #resultsWithWeirdNameToAvoidTempCollisions'
IF LEN(@SQL)>8000 RAISERROR ('MDX too long for openquery (exec_mdx_over_linked_server)',
16,
1);
if (@Debug = 1)
PRINT 'dbo.exec_mdx_over_linked_server SQL = ' + @SQL
DECLARE @colCount INT
EXECUTE sp_executesql @SQL, N'@expectedColCount SMALLINT, @ColCount SMALLINT OUTPUT', @expectedColCount = @expectedColCount, @colCount = @actualColCount OUTPUT
if (@Debug = 1)
BEGIN
PRINT '@expectedColCount = '; PRINT @expectedColCount
PRINT '@actualColCount = '; PRINT @actualColCount
END
-- correction for small float numbers (< 10E-10)
DECLARE @UpdateSql NVARCHAR(MAX) = N''
DECLARE @SmallThreshold FLOAT = 0.00000000001
SELECT @UpdateSql += '
UPDATE ' + @resultsTable + '
SET ' + QUOTENAME(COLUMN_NAME) + ' = 0
WHERE TRY_CONVERT (FLOAT, ' + QUOTENAME(COLUMN_NAME) + ') IS NOT NULL
AND ABS(' + QUOTENAME(COLUMN_NAME) + ') < ' + CAST(@SmallThreshold AS NVARCHAR(30))
FROM tempdb.INFORMATION_SCHEMA.COLUMNS with(NOLOCK)
-- WHERE table_name like @resultsTable + '[_][_][_]%'
-- changed, in order not to take into consideration objects from other spids
WHERE table_name = object_name(object_id('tempdb..' + @resultsTable), (select database_id from sys.databases where name = 'tempdb'))
IF (@Debug = 1)
BEGIN
PRINT '@UpdateSql = '; PRINT @UpdateSql;
END
EXEC (@UpdateSql);
END
它具有以下优点:
- 处理的情况下,当接收到的结果没有预期的列(执行任何操作)
- 执行一些圆角的非常小的数字(因为立方体知道浮点数的工作,这可能只发生)
- 所有MDX语句去通过单一程序
在进行分析时,我已经约注意到了。 100ms的开销(通过程序与对分析服务器直接执行执行)。
.NET开发人员可以使用ADOMD.NET框架,其允许运行参数化查询和具有较小的开销。
文章来源: How can I 'pull' data from an MDX OLAP Cube into a standard SQL Server table?