I would like to build a custom function with 3 parameters ,something like Oracle's substr function.
I want to use it to extract a value between a delimiter e.g. semicolon from a large text
the input parameter should be a blob data type to be able use large text.
then the 2nd and 3th parameter should define the occurrence of the delimiter
example
text= ; abc1 ; abc2 ; abc3 ;
select custom_function( text,2,3) from dual
will give me abc2.
It must be a function and I know I could use regexp_substr which is very easy but there is a limit of max length of the input string.
Related
I have
select
regexp_replace(city_name,',','') as city_name
, regexp_extract(regexp_replace(postal_cd,',','') ,'^(.*?)(?:-)(.*)$',1) as zip5
This works in Hue but I want to get the same output in SAS, so what can be the replacement for regexp_replace and regexp_extract function to work in sas?
I tried using replace but that is not working in sas
Use SAS functions prxchange to replace, and prxsubstr to extract.
Replacing a matching character with nothing can also be done with COMPRESS
Extract words from a delimited string can also be done with SCAN
The non regular expression ways (COMPRESS, SCAN) are generally faster because they are very specific in their implementation.
Example:
Use COMPRESS and SCAN
data have;
city = 'Spring,field';
zip = '1,2,3,4,5-6,7,8,9';
run;
proc sql;
create table want as
select
compress(city,',') as city
, scan(compress(zip,','),1,'-') as zip5
from
have
;
Trying to use the function COUNTW to get the number of "words" within a string.
But this string may sometimes contain NULL value when it is comma delimited;
I found some custom macro that can do that, just wondering if I can achieve the same with in-built function, COUNTW for example.
For example:
%put %wordcount('abc, , ,def,,56j,type',DLM=%str(,));
The above is a custom function, and it returns 7
%put %sysfunc(countw('abc, , ,def,,56j,type',%str(,)));
COUNTW returns 6 because it does not counting the NULL between 2 commas (",,")
Very simple, just look at the online documentation! COUNTW has optional modifiers, one of which is M which tells the function to include consecutive delimiters as a word, not null.
The following code returns 7, not 6.
%put %sysfunc(countw('abc, , ,def,,56j,type',%str(,),M));
Match strings ending in certain character
I am trying to get create a new variable which indicates if a string ends with a certain character.
Below is what I have tried, but when this code is run, the variable ending_in_e is all zeros. I would expect that names like "Alice" and "Jane" would be matched by the code below, but they are not:
proc sql;
select *,
case
when prxmatch("/e$/",name) then 1
else 0
end as ending_in_e
from sashelp.class
;quit;
You should account for the fact that, in SAS, strings are of char type and spaces are added up to the string end if the actual value is shorter than the buffer.
Either trim the string:
prxmatch("/e$/",trim(name))
Or add a whitespace pattern:
prxmatch("/e\s*$/",name)
^^^
to match 0 or more whitespaces.
SAS character variables are fixed length. So you either need to trim the trailing spaces or include them in your regular expression.
Regular expressions are powerful, but they might be confusing to some. For such a simple pattern it might be clearer to use simpler functions.
proc print data=sashelp.class ;
where char(name,length(name))='e';
run;
I have a column in Oracle which can contain up to 5 separate values, each separated by a '|'. Any of the values can be present or missing. Here are come examples of how the data might look:
100-1
10-3|25-1|120/240
15-1|15-3|15-2|120/208
15-1|15-3|15-2|120/208|STA-2
112-123|120/208|STA-3
The values are arbitrary except for the order. The numerical values separated by dashes always come first. There can be 1 to 3 of these values present. The numerical values separated by a slash (if it is present) is next. The string, 'STA', and a numerical value separated by a dash is always last, if it is present.
What I would like to do is reformat this column to only ever include the first three possible values, those being the three numerical values separated by dashes. Afterwards, I want to replace 2nd numeric in each value (the numeric after the dash) using the following pattern:
1 = A
2 = B
3 = C
I would also like to remove the dash afterwards, but not the '|' that separates the values unless there is a trailing '|'.
To give you an idea, here's how the values at the beginning of the post would look after the reformatting:
100A
10C|25A
15A|15C|15B
15A|15C|15B
112ABC
I'm thinking this can be done with regex expressions but it's got me a little confused. Does anyone have a solution?
If I have to solve this problem I will solve it in following ways.
SELECT
REGEXP_REPLACE(column,'\|\d+\/\d+(\|STA-\d+)?',''),
REGEXP_REPLACE(column,'(\d+)-(1)([^\d])','\1A\3'),
REGEXP_REPLACE(column,'(\d+)-(2)([^\d])','\1B\3'),
REGEXP_REPLACE(column,'(\d+)-(3)([^\d])','\1C\3'),
REGEXP_REPLACE(column,'(\d+)-(123)([^\d])','\1ABC')
FROM table;
Explanation: Let us break down each REGEXP_REPLACE statement one by one.
REGEXP_REPLACE(column,'\|\d+\/\d+(\|STA-\d+)?','')
This will replace the end part like 120/208|STA-2 with empty string so that further processing is easy.
Finding match was easy but replacing A for 1, B for 2 and C for 3 was not possible ( as per my knowledge ) So I did those matching and replacements separately.
In each regex from second statement (\d+)-(yourNumber)([^\d]) first group is number before - then yourNumber is either 1,2,3 or 123 followed by |.
So the replacement will be according to yourNumber.
All demos here from version 1 to 5.
Note:- I have just done replacement for combination of yourNUmber for those present in question. You can do likewise for other combinations too.
you can do this in one line, but you can write simple function to do that
SELECT str, REGEXP_REPLACE(str,'(\|\d+\/\d+)?(\|STA-\d+)?','') cut
, REGEXP_REPLACE(REGEXP_REPLACE(str,'(\|\d+\/\d+)?(\|STA-\d+)?',''), '(\-)([1,2]*)(3)([1,2]*)', '\1\2C\4') rep3toC
, REGEXP_REPLACE(REGEXP_REPLACE(REGEXP_REPLACE(str,'(\|\d+\/\d+)?(\|STA-\d+)?',''), '(\-)([1,2]*)(3)([1,2]*)', '\1\2C\4'), '(\-)([1,C]*)(2)([1,C]*)', '\1\2B\4') rep2toB
, REGEXP_REPLACE(REGEXP_REPLACE(REGEXP_REPLACE(REGEXP_REPLACE(str,'(\|\d+\/\d+)?(\|STA-\d+)?',''), '(\-)([1,2]*)(3)([1,2]*)', '\1\2C\4'), '(\-)([1,C]*)(2)([1,C]*)', '\1\2B\4'), '(\-)([B,C]*)(1)([B,C]*)', '\1\2A\4') rep1toA
, REGEXP_REPLACE(REGEXP_REPLACE(REGEXP_REPLACE(REGEXP_REPLACE(REGEXP_REPLACE(str,'(\|\d+\/\d+)?(\|STA-\d+)?',''), '(\-)([1,2]*)(3)([1,2]*)', '\1\2C\4'), '(\-)([1,C]*)(2)([1,C]*)', '\1\2B\4'), '(\-)([B,C]*)(1)([B,C]*)', '\1\2A\4'), '-', '') "rep-"
FROM (
SELECT '100-1' str FROM dual UNION
SELECT '10-3|25-1|120/240' str FROM dual UNION
SELECT '15-1|15-3|15-2|120/208' str FROM dual UNION
SELECT '15-1|15-3|15-2|120/208|STA-2' str FROM dual UNION
SELECT '112-123|120/208|STA-3' FROM dual
) tab
I've reviewed this question and I'm wondering my output seems to be a little skewed.
From my understanding the REGEXP_REPLACE method, takes a string that you want to replace content with, followed by a pattern to match, then anything that does not match that pattern is replaced with the substitution param.
I've written the following function to extract distance from a text field, in which a spatial query will be performed on the result.
CREATE OR REPLACE FUNCTION extract_distance
(
p_search_string VARCHAR2
)
RETURN VARCHAR2
IS
l_distance VARCHAR2(25);
BEGIN
SELECT REGEXP_REPLACE(UPPER(p_search_string), '(([0-9]{0,4}) ?MILES)', '')
INTO l_distance FROM SYS.DUAL;
RETURN l_distance;
END extract_distance;
When I run this in a block to test:
DECLARE
l_output VARCHAR2(25);
BEGIN
l_output := extract_distance('Stores selling COD4 in 400 Miles');
DBMS_OUTPUT.PUT_LINE(l_output);
END;
I'd expect the output 400 miles but in-fact I get Stores selling COD4 in. Where have I gone wrong?
"REGEXP_REPLACE extends the functionality of the REPLACE function by letting you search a string for a regular expression pattern. By default, the function returns source_char with every occurrence of the regular expression pattern replaced with replace_string." from Oracle docu
You could use, e.g.,
SELECT REGEXP_REPLACE('Stores selling COD4 in 400 Miles', '^.*?(\d+ ?MILES).*$', '\1', 1, 0, 'i') FROM DUAL;
or alternatively
SELECT REGEXP_SUBSTR('Stores selling COD4 in 400 Miles', '(\d+ ?MILES)', 1, 1, 'i') FROM DUAL;
You'll want to use, regexp_substr which returns a substring that matches the regular expression.
REGEX_SUBSTR