Tell me about implementing a series of data manipulation problems using LINQ or similar query constructs to filter and transform collections.
Use the Filevine matter activity data below. Write a SQL query that returns the requested result set.
| Column | Type | Description |
|---|---|---|
| matter_idPK | INT | Primary key for the matter |
| matter_name | VARCHAR(255) | Display name of the matter |
| is_active | BOOLEAN | Whether the matter is currently active |
| practice_area | VARCHAR(100) | Optional practice area label |
| Column | Type | Description |
|---|---|---|
| activity_idPK | INT | Primary key for the activity |
| matter_id | INT | References the related matter |
| activity_type | VARCHAR(50) | Type of activity |
| activity_status | VARCHAR(20) | Current activity status |
| activity_date | DATE | Date the activity was completed or scheduled |