Extract words in between the separator - snowflake-cloud-data-platform

Question

I have input like below
I want like below
I was trying with
Sales External?HR?Purchase Department
I did LISTAGG because finally i want in separate columns
Query Output would be like below,
meaning it should search for first occurrence of the separator (in this case "?", it can be anything but not common ones like "-" or "/" as the separator needs to be separate than sting value) and then extract the phrase before the first separator and create one column and put the value. Then it should look for second occurrence of the separator and then extract the word and keep creating columns, there can be multiple separators.
I tried with SPLIT_PART but it does not maintain the sequence in real data scenario and data does not come correct as per sequence.
I also tried with REGEXP_INSTR, but unable to use special characters as separators.
Any thought?

Answer 1

Regex Extract should work for you:
SELECT
REGEXP_SUBSTR_ALL("Sales External?HR?Purchase Department", "(.*)\?")
You can use LATERAL FLATTEN to convert your array into rows:
WITH MY_CTE AS (
SELECT
REGEXP_SUBSTR_ALL("Sales External?HR?Purchase Department", "(.*)\?")
)
SELECT
*
FROM
LATERAL FLATTEN(INPUT => MY_CTE, MODE=> 'ARRAY')
Deeper dive into some more cases: https://dwgeek.com/snowflake-convert-array-to-rows-methods-and-examples.html/

Answer 2

Here's a simplified version of the data. It uses a CTE with array_agg to group the rows. It then changes from arrays to columns. To add more columns, you can use max(), min(), or any_value() functions to get them through the aggregation. (Note that use of any_value() will not allow use of cached results from the result set cache since it's flagged as nondeterministic.)
create or replace table T1 (EMPID int, ROLE string, ACCESS string, ACCESS_LVL string, ITERATION string);
insert into T1(EMPID, ROLE, ACCESS, ACCESS_LVL, ITERATION) values
(1234, 'Sales Rep', 'Specific', 'REGION', 'DEV'),
(1234, 'Purchase Rep', 'Specific', 'EVERY', 'PROD'),
(1234, 'HR', NULL, 'Dept', 'PROD'),
(4321, 'HR', 'Foo', 'Foo', 'Foo')
;
with X as
(
select EMPID
,array_agg(nvl(ROLE,'')) within group (order by ROLE) ARR_ROLE
,array_agg(nvl(ACCESS,'')) within group (order by ROLE) ARR_ACCESS
,array_agg(nvl(ACCESS_LVL,'')) within group (order by ROLE) ARR_ACCESS_LVL
,array_agg(nvl(ITERATION,'')) within group (order by ROLE) ARR_ITERATION
from T1
group by EMPID
)
select EMPID
,ARR_ROLE[0]::string as ROLE1
,ARR_ROLE[1]::string as ROLE2
,ARR_ROLE[2]::string as ROLE3
,ARR_ACCESS[0]::string as ACCESS1
,ARR_ACCESS[1]::string as ACCESS2
,ARR_ACCESS[2]::string as ACCESS3
,ARR_ACCESS_LVL[0]::string as ACCESS_LVL1
,ARR_ACCESS_LVL[1]::string as ACCESS_LVL2
,ARR_ACCESS_LVL[2]::string as ACCESS_LVL3
,ARR_ITERATION[0]::string as ITERATION1
,ARR_ITERATION[1]::string as ITERATION2
,ARR_ITERATION[2]::string as ITERATION3
from X
;
There's nothing particular that seems interesting to sort the rows into the array so that ROLE1, ROLE2, ROLE3, etc. are deterministic. I showed simply sorting on the name of the role, but it could be any order by within that group.

Answer 3

Here's a stored proc that will produce a table result with a dynamic set of columns based on the input string and specified delimiter.
If you are looking for a way to generate dynamic column names based on values, I recommend visiting Felipe Hoffa's blog entry here:
https://medium.com/snowflake/dynamic-pivots-in-sql-with-snowflake-c763933987c
create or replace procedure pivot_dyn_results(input string, delimiter string)
returns table ()
language SQL
AS
declare
max_count integer default 0;
lcount integer default 0;
rs resultset;
stmt1 string;
stmt2 string;
begin
-- Get number of delimiter separated values (assumes no leading or trailing delimiter)
select regexp_count(:input, '\\'||:delimiter, 1) into :max_count from dual;
-- Generate the initial row-based result set of parsed values
stmt1 := 'SELECT * from lateral split_to_table(?,?)';
-- Build dynamic query to produce the pivoted column based results
stmt2 := 'select * from (select * from table(result_scan(last_query_id(-1)))) pivot(max(value) for index in (';
-- initialize look counter for resulting columns
lcount := 1;
stmt2 := stmt2 || '\'' || lcount || '\'';
-- append pivot statement for each column to be represented
FOR l in 1 to max_count do
lcount := lcount + 1;
stmt2 := stmt2 || ',\'' || lcount || '\'';
END FOR;
-- close out the pivot statement
stmt2 := stmt2 || '))';
-- execute the
EXECUTE IMMEDIATE :stmt1 using (input, delimiter);
rs := (EXECUTE IMMEDIATE :stmt2);
return table(rs);
end;
Invocation:
call pivot_dyn_results([string],[delimiter]);
call pivot_dyn_results('Sales External?HR?Billing?Purchase Department','?');
Results: