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Regular expression [message #578402] 
Wed, 27 February 2013 09:57 
rajivn786
Messages: 136 Registered: January 2010

Senior Member 


Hi,
Have 2 small tasks for regexp..where we need to extract numbers from the text & multiply & get the result.
Input field varchar2 : 5x a day x 10 days
Output : 5 * 10 = 50
Select regexp_replace('5x a day x 10 days', '[^[:digit:]]' from dual;
The code extracts numbers ..but doesn't multiply & give the result.
Have one more scenario as well.
Input field varchar2 : take 2 tablets (800 mg) by oral route every 4 hours while awake for 10 days
Output : 2 * 800 * 4 * 6 * 10 = 384000
Select regexp_replace('take 2 tablets (800 mg) by oral route every 4 hours while awake for 10 days', '[^[:digit:]]' from dual;
For the above code, if it's hours ..we need to convert into day by multiplying with the required factor to make it a day.
So, since it's 4, I had to multiply it by 6 to make it a day.



Re: Regular expression [message #578404 is a reply to message #578402] 
Wed, 27 February 2013 11:24 

Michel Cadot
Messages: 58604 Registered: March 2007 Location: Nanterre, France, http://...

Senior Member Account Moderator 


Here are 3 ways to get the result of the multiplication (the 9 first lines are always the same ones).
DBMS_XMLGEN (also works in 10g):
SQL> with
2 data as (
3 select 'take 2 tablets (800 mg) by oral route every 4 hours while awake for 10 days' val
4 from dual
5 ),
6 inter as (  just to show the result of regexp_replace
7 select trim(both '*' from regexp_replace(val,'[^[:digit:]]+','*')) multiplication
8 from data
9 )
10 select multiplication,
11 to_number(
12 extractvalue(
13 dbms_xmlgen.getxmltype('select 'multiplication' from dual'),
14 '//text()')) total
15 from inter
16 /
MULTIPLICA TOTAL
 
2*800*4*10 64000
XMLQuery:
SQL> with
2 data as (
3 select 'take 2 tablets (800 mg) by oral route every 4 hours while awake for 10 days' val
4 from dual
5 ),
6 inter as (  just to show the result of regexp_replace
7 select trim(both '*' from regexp_replace(val,'[^[:digit:]]+','*')) multiplication
8 from data
9 )
10 select multiplication, xmlquery(multiplication returning content).getNumberVal() total
11 from inter
12 /
MULTIPLICA TOTAL
 
2*800*4*10 64000
If OLAP option is installed:
SQL> with
2 data as (
3 select 'take 2 tablets (800 mg) by oral route every 4 hours while awake for 10 days' val
4 from dual
5 ),
6 inter as (  just to show the result of regexp_replace
7 select trim(both '*' from regexp_replace(val,'[^[:digit:]]+','*')) multiplication
8 from data
9 )
10 select multiplication, dbms_aw.eval_number(multiplication) total
11 from inter
12 /
MULTIPLICA TOTAL
 
2*800*4*10 64000
The rest is not clear. Why "2 * 800 * 4 * 6 * 10"?
Regards
Michel
[Edit: modify the query to show the multiplication text]
[Updated on: Wed, 27 February 2013 11:32] Report message to a moderator



Re: Regular expression [message #578405 is a reply to message #578404] 
Wed, 27 February 2013 11:37 

Littlefoot
Messages: 19320 Registered: June 2005 Location: Croatia, Europe

Senior Member Account Moderator 


And here's a straightforward way to do that calculation:
SQL> with test as
2 (select '5x a day x 10 days' col
3 from dual
4 )
5 select regexp_substr(col, '\d+', 1, 1) *
6 regexp_substr(col, '\d+', 1, 2) result_1
7 from test;
RESULT_1

50
SQL>
SQL> with test as
2 (select 'take 2 tablets (800 mg) by oral route every 4 hours while awake for 10 days' col
3 from dual
4 )
5 select regexp_substr(col, '\d+', 1, 1) *
6 regexp_substr(col, '\d+', 1, 2) *
7 regexp_substr(col, '\d+', 1, 3) * 24 / regexp_substr(col, '\d+', 1, 3) *
8 regexp_substr(col, '\d+', 1, 4) result_2
9 from test;
RESULT_2

384000
SQL>



Re: Regular expression [message #578406 is a reply to message #578404] 
Wed, 27 February 2013 11:39 
rajivn786
Messages: 136 Registered: January 2010

Senior Member 


Thanks Mike..That's helpful.
The reason , I'm multiplying it by 6 is to convert number of hours into a day.
Since it's 4 hours, it's 4*6..which makes it a day.
That means the patient took 6 pills per day.




Re: Regular expression [message #578409 is a reply to message #578408] 
Wed, 27 February 2013 11:55 
rajivn786
Messages: 136 Registered: January 2010

Senior Member 


Usually it will be one of the following for hours (multiples of 24)  2,3,4,6,8 ..
Can we modify the below query to include all the above combinations if the text has hours in it??
Ex : If it's 2 multiply by 12,
3 multiply by 8 etc...



Re: Regular expression [message #578410 is a reply to message #578409] 
Wed, 27 February 2013 12:38 

Michel Cadot
Messages: 58604 Registered: March 2007 Location: Nanterre, France, http://...

Senior Member Account Moderator 


Assuming there is always "X hours":
SQL> with
2 data as (
3 select 'take 2 tablets (800 mg) by oral route every 4 hours while awake for 10 days' val
4 from dual
5 ),
6 fixing as (
7 select regexp_replace(val, '([[:digit:]]+ hours)', '24/\1') val
8 from data
9 ),
10 inter as (  just to show the result of regexp_replace
11 select trim(both '*' from regexp_replace(val,'[^[:digit:]/]+','*')) multiplication
12 from fixing
13 )
14 select multiplication, dbms_aw.eval_number(multiplication) total
15 from inter
16 /
MULTIPLICATIO TOTAL
 
2*800*24/4*10 96000
Regards
Michel





Re: Regular expression [message #578413 is a reply to message #578402] 
Wed, 27 February 2013 13:57 
rajivn786
Messages: 136 Registered: January 2010

Senior Member 


Mike,
I'm using dbms_xmlgen method. There are some cases in my data where it's completely text.
I can keep a where condition to filter the records.
But may I know what should be added to the query to handle text as it gives me error.



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