SSRS - Graph Line Value for Parameter For the purpose of reporting database growth, I am created everything except one and most important thing. In SSDT I'm created report, which contains graph line which need to be show in depend of parameters. I have drop-down list of databases, graph where are in sections: VALUES (Fields!dataSize.Value), Category Groups(date), Series Groups (databaseName). 
I have parameter databases_id (dataset1, value field: id, label field: databaseName). 

When I start report and select some database and click on VIEW REPORT, I get lines for every parameters(databases) on list. How to get only lines for selected parameters(databases)?
You need to refer to the parameters in your main sql query. 

Something like: 

Where databaseName = @databases 

Or if you want to be able to select multiple databases.

Where databaseName in (@databases)

Here is an example using date parameters and multi-select parameters in a report https://technet.microsoft.com/en-us/library/aa337396(v=sql.105).aspx

If you Google " ssrs parameter sql query" there are lots of working examples and even some youtube videos giving step by step instructions.