Sqlite question: group by column with multiple tags?

[Yuzem]

Suppose that have 2 columns: folders and tags:

~/Music|classic,rock
~/Music|classic,rock
~/Pictures|art,photos
~/Pictures|art,photos
~/Pictures|art,photos

To know the folder count I do:

sqlite3 test.db  "select folder, count(folders) from t1 group by folder"

Returns:

~/Music|2
~/Pictures|3

How can I do the same for tags using only sqlite to get this:

art|3
classic|2
photos|3
rock|2

Another question, is there any way to get max count for all grouped columns in one single consult?
It should return something like this:

2|4

Meaning that the first column has 2 unique values (~/Music and ~/Pictures) and the second column has 4 (art, classic. photos and rock)

Many thanks in advance!

[Yuzem]

Maybe if I ask in a different way: What is the standard way of storing and counting tags with sqlite?

[The Cog]

I would not put multiple tags in one column. If it were arranged more like this:

~/Music|classic
~/Music|rock
~/Pictures|art
~/Pictures|photos

then you can do things like:

select folder, count(*) from t1 group by folder
select tag, count(*) as numfolders from t1 group by tag order by numfolders limit 1

The "limit 1" is mysql's way of getting just the first line. I don't know what the equivalent syntax for sqlite is.
I don't know how to get both maxes at once.

[Yuzem]

Thanks for the answer.

I would not put multiple tags in one column.

Yes it seems that that is the way to do it, I have also asked here and I got the same answer.