replace string in whole database mysql stackoverflow

1DECLARE col_names CURSOR FOR
2  SELECT column_name
3  FROM INFORMATION_SCHEMA.COLUMNS
4  WHERE table_name = 'tbl_name'
5  ORDER BY ordinal_position;
6
7
8select FOUND_ROWS() into num_rows;
9
10SET i = 1;
11the_loop: LOOP
12
13   IF i > num_rows THEN
14        CLOSE col_names;
15        LEAVE the_loop;
16    END IF;
17
18
19    FETCH col_names 
20    INTO col_name;     
21
22     //do whatever else you need to do with the col name
23
24    SET i = i + 1;  
25END LOOP the_loop;