CC's sort, group, and search functions are very capable, but it might not be obvious how to use all it can do.
First, what do we mean by "grouping"? These are functions to show you books and metadata (data about books) in an organized way. For example, you can easily find all the authors of books on your device. Same for series, tags, and publishers. Tap the "Group" menu on the top and select the view you want.
You can sort a list of books no matter how you got there. For example, assume you are looking at a list of books with some tag "Books I like" that you are seeing because you use the Group function. You can sort that list by series, author, or any other choice on the Sort menu.
However, what do you do if you want something a bit more complicated, such as to see a list of authors of books tagged with "Books I like"? This is where Search come in. Searching in CC produces a list of books that match the search criteria. You can then use grouping and sorting on that list. CC uses calibre's search syntax. Continuing the example, searching for tags:"=Books I like" will find all books with that tag. To see the authors of these books, group by Author. To see the series of these books, group by Series.
For simple searches, CC provides a shortcut that avoids the tedious typing. To search for a tag, first group by Tags and then navigate to that tag. Using the same example of "Books I like", when I first group by Tags I will see a list of first letters (unless you turned that off in Settings). Tap "B" and you will see tags beginning with B, which will include "Books I like". If you long-tap on "Books I like", a dialog will open asking you if you want to search for that tag, and if so do you want all books with the tag or all books without the tag. Make the choice you want, press OK, and the search is done. You can now group, sort, etc.
Note that when you search for a book with some tag, you may see other tags in the group list. This happens if the selected books have more than one tag.
Long tap works on any item displayed while grouping, including the first letters. You can long-tap on the first letter to all items that begin with that letter.
You can undo a long-tap search (or a search you entered) by tapping on the list header, the one saying that a search is active and how many books were found.
Several fields can be searched using greater than, less than, etc. Examples:
- rating:>=3 will find all books with rating greater than or equal to 3
- pubdate:<2000 will find books published before the year 2000.
- date:<=2000-04 will find books with calibre's date field less than or equal to April 2000.
The permitted operators are < (less than), = (equal to), > (greater than), <= (less than or equal to), and >= (greater than or equal to). You can search for not equal to using "not ratiing:=2"
Another sorting tip: sorting by something then sorting by that something again will invert the sort. This lets you sort descending and ascending.