Skip to main content

Display Top N Rows - Alternate Method

In a previous post, I showed how to dynamically limit the number of rows shown in a table or matrix. This methodology used a filter on the table to only show the desired number of rows. The disadvantage with this method is that all rows are returned, even if only a small subset of rows is actually desired.

To alleviate this problem, you can use a query parameter to restrict the number of rows returned at the query level. This does introduce a different problem. Every time the report is run with a different Top N parameter, the query will be rerun to bring back the correct number of rows. You will need to determine which method is optimal for your situation.

Here are the steps to create a sample report to show this new method.

1. Add a report parameter named “NumberPpl” of data type integer.

2. Create a DataSource connecting to the AdventureWorksDW database and a DataSet with the following query:
SELECT TOP(cast(@TopN as int)) DimEmployee.FirstName, DimEmployee.LastName, SUM(FactResellerSales.SalesAmount) AS SalesAmount
FROM DimEmployee INNER JOIN
FactResellerSales ON DimEmployee.EmployeeKey = FactResellerSales.EmployeeKey
WHERE (FactResellerSales.OrderDateKey = 20011001)
GROUP BY DimEmployee.FirstName, DimEmployee.LastName
ORDER BY SUM(FactResellerSales.SalesAmount) DESC
Assign the @TopN query parameter to use the @NumberPpl report parameter.

Note that this differs from the original query in two ways:
A. Includes the TOP clause to restrict the rows
B. Includes a descending order by for the SalesAmount to ensure the highest SalesAmounts are shown

Also note that the TopN query parameter is cast to an integer. This is because all query parameters are created as string and the TOP clause expects an integer.

3. Add a table to the body of the report with the data fields of FirstName, LastName, and SalesAmount. Sort by the column SalesAmount from ‘Z to A’. This sort is now only for display purposes and is not necessary to return the correct data.

4. Preview the report, modifying the value for the parameter NumberPpl to see the number of rows change. It should look similar to the report below and the reports using the first method.

Version: SQL Server 2008 RTM

Comments

Anonymous said…
Jessica, I have a situation and I am hoping that you will have an answer. I have a matrix and it returns different number of rows based on a parameter selected. I would love to have the first page with the first 9 results and the remaining in the next page limiting the page display to 9 results till the end of the rowset. Think you can help me out. I cannot restrict the rows returned by using a parameter. However, I can assign a number to the display rows as you have shown in your example. This I am gussing is an extension of your solution. Think you can help me.
Jessica M. Moss said…
Hi Anon,

I would recommend posting your question on the MSDN forum - then multiple people can help.

Best,
Jessica

Popular posts from this blog

SSIS Configuration to Configuration to Configuration Schema

I've gotten several requests to put down in writing the configuration schema that I use as the base of my SQL Server Integration Services framework. It contains a set of configurations: an indirect environment variable configuration, which points to an XML configuration file configuration, which points to a SQL Server configuration. I learned this configuration from the Project REAL Reference Implementation . If you're getting started with a BI implementation, I highly recommend that you download it for some great ideas and best practices. Steps to implement: 1) Create an environment variable on your machine with the name of SSIS_CONFIG_FILE and the value of: C:\SSIS\Config\MasterConfigFile.dtsConfig. 2) Create an SSIS configuration file at C:\ SSIS\Config\MasterConfigFile.dtsConfig with the line: <configuration valuetype="String" path="\Package.Connections[CONFIG_SERVER].Properties[ConnectionString]" configuredtype="Property"><configuredv

Execute SQL Task Designer Limit

After migrating a package from DTS to SSIS, I had a problem with an Execute SQL Task. I couldn't change any characters in the SQLStatement property; I couldn't add any new characters; I could delete characters, but not retype them! After googling several variations of "integration services" "read only" and "Execute SQL Task", I deleted about half of the entry in a fit of frustration. Lo and behold, I could type again. Apparently, there is limit on the size or number of characters that can be entered in the SQLStatement property. From my experimentation, I came up with a limit of 32767 characters. The interesting thing is that the restriction only seems to be on the designer. If you set the SourceType to "Variable" and use a variable that contains more than 32767 characters, the task will execute. Also, if you use the "Direct Input" SourceType and modify the package XML to set the SQLStatement longer than 32767 characters,

Reporting Services 2008 Configuration Mistake

To start working with the management side of SQL Server Reporting Services 2008, I decided to set up a report server and report manager. Unfortunately, I made a mistake while setting up my configuration that left me a little perplexed. Here are the steps I took to cause, track down, and solve the issue. Problem: I began by opening the Reporting Services Configuration Manager from the Start Menu. I clicked through each of the menu options and accepted the defaults for any question with a warning symbol, since warning symbol typically designate an action item. After two minutes, all of the warning symbols had disappeared, and I was ready to begin managing my report server. Unfortunately, opening up a browser and trying to open up the report manager resulted in the dreaded " The report server has encountered a configuration error. (rsServerConfigurationError) " message. Sherlock-ing it: I put on my sleuthing hat and went to the log file directory: C:\Program Files\Microsoft