Question

I did a bit of research about sql escape characters and count statements and didnt find a solution to my question. Even though I used stuff like:

SELECT * FROM table WHERE path LIKE '%/_%' ESCAPE '/';

I got a table where in a column there is paths so I want to select the items where I have certain number of slashes:

ID    DIRECTORY
1     root/A
2     root/B
3     root/A/1/2
4     root/B/1/2
5     root/A/1
6     root/B/2

so, how do I select for example the elements that have only 2 slashes??

Edit 1: This is to be done in Android SQL-Lite Database

Answer 1

You can use this trick to count occurrences of a character in a string:

SELECT LENGTH('path') - LENGTH(REPLACE('path', '/', '')) AS `occurrences`

So you can achieve the goal with

SELECT id, path FROM
  (SELECT id, path, LENGTH('path') - LENGTH(REPLACE('path', '/', '')) AS `occurrences`
   FROM table) temp
WHERE occurrences = 2

However, I expect performance will be terrible. If you are going to query like that, consider adding a column with the path depth so that you can query directly with

SELECT id, path FROM table WHERE depth = 2