Extract a number (or specific value) from a string for calculation purposes

Question

Hi everyone
I have a column other_remarks (for general medical remarks of string(300)). In that field doctors are writing many inormative details, found while examining a patient.
== Sample Data ==
"test asdad asd asdhkl BMI 30 askdhja ad has 45"
"patient is improving BMI: 30 askdhja ad has weight 89"
"BMI:20 ghghh jkghjk hjgfj akls dkl 234 fasdf2345 sda234"
I want to extract the number written after word BMI or want to calculate how many patients have BMI:
(i) less than 30,
(ii) and >= 30 and <45 , and
(iii) more than 45.
Please note that every user is writing BMI word first and than the the integer value, while there might be many other numbers in the string. And I have Oracle9i Enterprise Edition Release 9.2.0.6.0 which dont have REGEXP_Replace function available.
Edited by: 870532 on Jul 5, 2011 11:53 PM

Answer 1

SQL> with sample_data
  2  as
  3  (select 'test asdad asd asdhkl BMI 30 askdhja ad has 45' val from dual union all
  4  select 'patient is improving BMI: 30 askdhja ad has weight 89' from dual union all
  5  select 'BMI:20 ghghh jkghjk hjgfj akls dkl 234 fasdf2345 sda234' from dual
  6  )
  7  SELECT Substr(REPLACE(REPLACE(val, ' '), ':', ''), Instr(
  8                REPLACE(REPLACE(val, ' '), ':', ''), 'BMI') + 3, 2) BMI
  9  FROM   sample_data;
BMI
30
30
20
3 rows selected.