Count number of unique characters in a string

Question

I\'m looking for a sql statement to count the number of unique characters in a string.

e.g.

3333333333 -> returns 1
1113333333 -> returns 2
111         


        

Answer 1

I think this is not a job for Mysql, but you could do anything if you try hard enough ;)

I don't like this answers but it works, and it's not too ugly if you have only numbers

SELECT 
    CASE WHEN yourcolumn LIKE '%1%' THEN 1 ELSE 0 END + 
    CASE WHEN yourcolumn LIKE '%2%' THEN 1 ELSE 0 END +
    CASE WHEN yourcolumn LIKE '%3%' THEN 1 ELSE 0 END + 
    CASE WHEN yourcolumn LIKE '%4%' THEN 1 ELSE 0 END +
    CASE WHEN yourcolumn LIKE '%5%' THEN 1 ELSE 0 END +
    CASE WHEN yourcolumn LIKE '%6%' THEN 1 ELSE 0 END +
    CASE WHEN yourcolumn LIKE '%7%' THEN 1 ELSE 0 END +
    CASE WHEN yourcolumn LIKE '%8%' THEN 1 ELSE 0 END +
    CASE WHEN yourcolumn LIKE '%9%' THEN 1 ELSE 0 END +
    CASE WHEN yourcolumn LIKE '%0%' THEN 1 ELSE 0 END
FROM yourtable