Cascading Parameters

Cascading parameters allow you to create dependent dropdowns in SSRS reports. This means that the available choices in a dropdown list are based on the value selected in a previous dropdown list. This can greatly enhance the user experience and make reports more intuitive.

Syntax

There is no specific syntax for cascading parameters in SSRS since it is a feature of the report builder and not a function or expression. However, there are a few important steps to follow:

1. Create the first parameter in the usual way.
2. Create a dataset for each subsequent parameter that depends on the previous parameter.
3. Set the default value of each subsequent parameter to be based on the previous parameter.
4. Set the Available Values of each subsequent parameter to come from a dataset that filters based on the previous parameter.

Example

Suppose we have a report that shows sales data by region, country, and city. We want to create cascading parameters so that when the user selects a region, the available choices for the country dropdown are limited to only those countries within that region, and when a country is selected, the available choices for the city dropdown are limited to only those cities within that country.

To do this, we would follow these steps:

1. Create a parameter called Region that gets its list of available values from a dataset of all regions.
2. Create a dataset called CountryList that gets its values from a table of all countries. The query for this dataset should include a WHERE clause that filters by the selected region: WHERE Region = @Region.
3. Create a parameter called Country that gets its list of available values from the CountryList dataset. Set its default value to come from the Region parameter.
4. Create a dataset called CityList that gets its values from a table of all cities. The query for this dataset should include a WHERE clause that filters by the selected country: WHERE Country = @Country.
5. Create a parameter called City that gets its list of available values from the CityList dataset. Set its default value to come from the Country parameter.

When the report is run, the user will first select a region, which will limit the available choices in the country dropdown. After a country is selected, the available choices in the city dropdown will be further restricted based on the selected country.

Explanation

Cascading parameters work by filtering the available choices for subsequent dropdowns based on the selected value in the previous dropdown. This is done by creating datasets for each subsequent parameter that are filtered based on the previous parameter, and setting the Available Values for each subsequent parameter to come from their respective datasets.

Use

Cascading parameters can be used whenever you have related data that you want to group together in dropdowns. This is particularly useful when you have a large amount of data and you want to make it easier for users to find specific items.

Important Points

• Cascading parameters require that the available choices for each subsequent parameter be based on the selected value in the previous parameter.
• When creating cascading parameters, it is important to set the default value and available values for each parameter correctly.
• Cascading parameters can greatly enhance the user experience and make reports more intuitive.

Summary

Cascading parameters allow you to create dependent dropdowns in SSRS reports. This means that the available choices in a dropdown list are based on the value selected in a previous dropdown list. Cascading parameters work by filtering the available choices for subsequent dropdowns based on the selected value in the previous dropdown. They can be used whenever you have related data that you want to group together in dropdowns, and can greatly enhance the user experience and make reports more intuitive.