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Sunday, 30 September 2012

ERROR: An item with the same key has already been added

During the process of creating Multi value report. I received the following error while previewing the report
“An item with the same key has already been added.”.















I got irritate when fetch the report MDX through Sql server profiler it ran with no error. After doing lot of research my friend gave a hint (he was having the same problem using TSQL Stored procedure) and resolved my issue. The issue was due to I  added the two fields with same name .
Quick Solution
1.    Go to the report query, stored procedure and identify the duplicate fields and remove it.
2.     If the report is using MDX go to the .rdl code and identify the duplicate fields and remove it.
3.    In MDX report if the field name is different but Unique name is same as highlighted in red below than we can also experience this error
<Field Name="Average_Unit_Price">
<DataField>&lt;?xml version="1.0" encoding="utf-8"?&gt;&lt;Field xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:type="Measure" UniqueName="[Measures].[Average Unit Price]" /&gt;</DataField>
<rd:UserDefined>true</rd:UserDefined>
</Field>
<Field Name="Average_Unit_Price">
<DataField>&lt;?xml version="1.0" encoding="utf-8"?&gt;&lt;Field xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:type="Measure" UniqueName="[Measures].[Average Unit Price]" /&gt;</DataField>
<rd:UserDefined>true</rd:UserDefined>
</Field>



Saturday, 29 September 2012

Execute MDX Query with TSQL

To start with execution of MDX query with TSQL first we need to create a Linked Server. Let’s discuss few points regarding this
Linked Server
  Linked server enables the SQL Server Database Engine to execute commands against OLE DB data sources outside of the instance of SQL Server. Linked servers are configured to enable the Database Engine to execute a Transact-SQL statement that includes tables in another instance of SQL Server, or another database product such as Oracle, mysql, MS Analysis services etc. Many types of OLE DB data sources can be configured as linked server.
Now let’s proceed with creation of linked server within the sqlserver instance
Create a linked server
·         To create a linked sever you must have admin right of SqlServer.
·         Navigate to Server Objects > Linked Servers
·         Right click on Linked Servers and select New Linked Server.
Let’s take a sample cube database AdventureWorksDW2008R2 and create a linked server on this.

EXEC
sp_addlinkedserver
@server='Test', /* Here specify a name to linked server */
@srvproduct='',/*Is the product name of the OLE DB data source to add as a linked server. product_name is nvarchar(128), with a default of NULL.*/
@provider='MSOLAP',/*Is the unique programmatic identifier (PROGID) of the OLE DB provider corresponding to this data source. provider_name must be unique for the specified OLE DB provider installed on the current computer.*/
@datasrc='localhost',/*'DRIVER={SQL Server};Server=(local); Initial Catalog=master;Integrated Security=SSPI;'*/
       @catalog='Adventure Works DW 2008R2' /*Cube Database Name*/
4.       Once the linked server is set, we need TSQL Rowset OPENQUERY function.
Open Query

Executes the specified pass-through query on the specified linked server. This server is an OLE DB data source. OPENQUERY can be referenced in the FROM clause of a query as if it were a table name. OPENQUERY can also be referenced as the target table of an INSERT, UPDATE, or DELETE statement. This is subject to the capabilities of the OLE DB provider. Although the query may return multiple result sets, OPENQUERY returns only the first one.

Syntax: - OPENQUERY (linked_server,’query’)
Now you can write your Script
USE
AdventureWorksDW2008R2
GO
Declare @MDXExpression as Varchar(MAX)

Create Table  #temp(
                        Country varchar(Max),
                        Sale_Amount  float,
                        Product_cost float,
                        Tax_amount Float,
                        TProduct_Cost Float
                        )

Set  @MDXExpression =
'SELECT
NON EMPTY
      {
      [Measures].[Sales Amount]
      ,[Measures].[Standard Product Cost]
      ,[Measures].[Tax Amount]
      ,[Measures].[Total Product Cost]
      } ON 0,
NON EMPTY
      {
NonEmpty ( [Sales Territory].[Sales Territory Region].[Sales Territory Region])

      } ON 1
FROM
      [Adventure Works]';     

insert into #temp     
Exec ('SELECT * FROM OpenQuery(Test,''' + @MDXExpression + ''')')

/* Here you can join your MDX result set with your respective Sql server database tables and can extract expected result set */

SELECT      SalesTerritoryGroup,  #temp.*
FROM         DimSalesTerritory inner join #temp   on #temp.[Country]= DimSalesTerritory.SalesTerritoryCountry

Friday, 28 September 2012

#ERROR/NAN / error: Input string was not in a correct format issue in SSRS

While working on reports, we usually get “#ERROR”,”N/A” or “error: Input string was not in a correct format”error.
The major problem behind these issues is data type mismatches and some additional reasons that cause these issues.
Let’s talk about how to resolve these issues and why we get these issues.
1.    If you are performing any aggregate operation like SUM, AVG etc  on the report and also you know that your input field might have string value then never use an expression like
=sum(iif(isnumeric(Fields!YourFieldName.Value), cdbl(Fields!YourFieldName.Value),0))
OR
=sum(iif(isnumeric(Fields!YourFieldName.Value), cint(Fields!YourFieldName.Value),0))
OR
=sum(iif(isnumeric(Fields!YourFieldName.Value), iif(isnumeric(Fields!YourFieldName.Value),cdbl(Fields!YourFieldName.Value),0),0))

The reason behind this is ISNUMERIC() method works in a mysterious way. If we will try to explorer this method a bit more in detail then we will find that is ISNUMERIC()returns true for any expression if there will be any possibility to convert the expression in numeric. For example, if you test ISNumeric("1,234.55") will return true whereas SUM("1,234.55")will give you #Error. To resolve this sitution

Always use expression like =SUM(VAL(Fields!YourFieldName.Value))

2.    If you are using cube/MDX report and also using your aggregate expression like above but still getting an error or an unexpected result then you need to check these points
·         Start your sql server profiler (Tools menu-> Sql Server Profiler) with Analysis services as service type. Execute/Preview your report and extract/copy the MDX from the profile. Now execute this MDX on the Analysis Services query browser. Make sure that your report’s aggregate column is available in the output. If you see your column unavailable in the output then you need to play a workaround to get include your missing column in the output.
            The reason behind this missing column is if the resultant of your entire column is NULL and you are using Non empty/Nonempty then query engine exclude the column from the output to increase the query response time.

To resolve this problem, you need to add a calculate Member in your MDX query and append the expression by adding +0 at the end like :

With
Member CalculatedMember as [Measures].[Measure Name]+0

·         Sometime due to mishandling the expression in the MDX query/Calculated measure, we get “Infinity”,”N/A” or scientific numeric format like 1.00E+12 in the MDX output.

To see the expected result at report level, we need to handle these problems at MDX level by using appropriate expression/fields/methods.

Exclude Week End Days From Calendar

Today I found a post at MSDN to exclude Sunday using Datediff(). I worked around the query and found a solution

declare @start datetime,
              @end datetime

set @start = '2006-01-01'
set @end =   '2006-01-08'
;
with calendar(date,isweekday, y, q,m,d,dw,monthname,dayname,w) as
(
select @start ,
case when datepart(dw,@start) in (1,7) then 0 else 1 end,
year(@start),
datepart(qq,@start),
datepart(mm,@start),
datepart(dd,@start),
datepart(dw,@start),
datename(month, @start),
datename(dw, @start),
datepart(wk, @start)
union all
select date + 1,
case when datepart(dw,date + 1) in (1,7) then 0 else 1 end,
year(date + 1),
datepart(qq,date + 1),
datepart(mm,date + 1),
datepart(dd,date + 1),
datepart(dw,date + 1),
datename(month, date + 1),
datename(dw, date + 1),
datepart(wk, date + 1) from calendar where  date + 1<= @end
)
select * into #test from calendar option(maxrecursion 10000)
Select  DATEDIFF(DD,@start,@end)+1-Count(case when #test.isweekday=0 then #test.isweekday end )
from #test where #test.date between @start and @end

You can also find the solution in this way

SELECT startDate,EndDate,DATEDIFF(DD,startDate,EndDate) FROM Production.WorkOrder WHERE ((DATEPART(dw, StartDate) + @@DATEFIRST) % 7) NOT IN (0, 1)

How to restrict/set number of records per page in SSRS report

Sometimes we came into a situation where we need to show only a specific number of records on per page.
Let’s see how we can restrict the number of records on per page. I am assuming that you are good with your report design. So I will focus only on the required expressions/steps that will need us to achieve required page break in the report.
Step 1: Add a Parent Group under Row Group section. Now on popup window under Group by:” dropdown, use this expression:
Image -1
=Int((RowNumber(Nothing)-1)/10)
In this expression, you need to change 10 to
any desire number as you wish to see number of records on per page
Image-1 will help you regarding this step.
Step 2: Open the group properties window(Right Click on group name-> select Group Properties) of this newly added group.             
Image -2
           Go to Page Breaks and checked “Between each instance of the group”.
           Now go to Sorting and delete column/sorting expression (if any).
           You can also delete the 1st column of your table that has been created automatically on action of add new group by choosing “Delete Columns only” option from the prompt.

           Image-2 will help you regarding this step.
Now you are done. Preview your report and check report output.

You can download the sample report from following link.