When dealing with potentially nullable input parameters in SQL queries, it is best practice to use dynamic conditional constructs to prevent null values from interfering with query logic. Here are a few effective ways to do this:
1. SELECT * FROM products
2. WHERE (category_id = @category_id OR @category_id IS NULL)
3. AND (price > @min_price OR @min_price IS NULL)
4. AND (brand_name = @brand_name OR @brand_name IS NULL)
This approach ensures that when any parameter is NULL, the corresponding condition will not filter any records, while keeping other valid conditions working normally.