Cascading parameters

You can create a cascading parameter set that has a single parameter driving a child and grandchild parameter. This should accomplish what you are looking for. For example, if you wanted to get a list of orders for customers in a particular country by either sale rep id or by the customer's city you could create a top level parameter that is prompting for country. The next level parameter would utilize the country in determining the list of citys to display. Likewise, the last paramter would utilze the country to determine the list of sales reps. Both the city and the rep id would be utilized by the data set's query in an or condition.The only oddity is if you refresh your parameter display in the designer or the web veiwer, it remembers last select and does not clear all the parameters when you change the first one.Rob

In the situation I described above, if you make country optional, you will need to ensure that they way you have constructed your query will return all the rows. To make a query optional, make sure the "Is Required" check box in they query editor is not check. The following link gives an example of controlling or changing a query based upon a parameter.<br />
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<a class='bbc_url' href='http://www.birt-exchange.com/modules/wfdownloads/singlefile.php?cid=2&lid=176'>http://www.birt-exchange.com/modules/wfdownloads/singlefile.php?cid=2&lid=176</a><br />
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Rob