Oracle- Split string comma delimited (string contains spaces and consecutive commas) - sql

Question

I can't find a solution about how to split a comma-delimited string in ORACLE. Searched a lot, nothing works for my case
Code
DECLARE
TYPE T_ARRAY_OF_VARCHAR IS TABLE OF VARCHAR2(2000) INDEX BY BINARY_INTEGER;
MY_ARRAY T_ARRAY_OF_VARCHAR;
MY_STRING VARCHAR2(2000) := '12 3,456,,abc,def';
BEGIN
FOR CURRENT_ROW IN (
with test as
(select MY_STRING from dual)
select regexp_substr(MY_STRING, '[^,]+', 1, rownum) SPLIT
from test
connect by level <= length (regexp_replace(MY_STRING, '[^,]+')) + 1)
LOOP
DBMS_OUTPUT.PUT_LINE('>' || CURRENT_ROW.SPLIT || '<');
--DBMS_OUTPUT.PUT_LINE(CURRENT_ROW.SPLIT);
MY_ARRAY(MY_ARRAY.COUNT) := CURRENT_ROW.SPLIT;
END LOOP;
DBMS_OUTPUT.PUT_LINE('Array Size:' || MY_ARRAY.COUNT);
END;
/
The output is:
>12 3<
>456<
>abc<
>def<
><
Array Size:5
The empty value is out of order!!!!

Answer 1

Try this for the parsing the list part. It handles NULLS:
SQL> select regexp_substr('12 3,456,,abc,def', '(.*?)(,|$)', 1, level, null, 1) SPLIT, level
from dual
connect by level <= regexp_count('12 3,456,,abc,def',',') + 1
ORDER BY level;
SPLIT LEVEL
----------------- ----------
12 3 1
456 2
3
abc 4
def 5
SQL>
Unfortunately when you search for regex's for parsing lists, you will always find this form which does NOT handle nulls and should be avoided: '[^,]+'. See here for more info: Split comma separated values to columns in Oracle.

Answer 2

Try xmltable and flwor expresion.
The following example is not secure and throw error if you put string without comma. But is simpler to understand.
select xmlcast(column_value as varchar2(2000)) value_list
from xmltable('for $val in ora:tokenize($strList,",")
return $val'
passing '12 3,456,,abc,def' as "strList"
);
And secured version.
select xmlcast(column_value as varchar2(2000)) value_list
from xmltable('for $val at $index in ora:tokenize(concat(",",$strList),",")
where $index > 1
return $val' passing '12 3,456,,abc,def' as "strList"
);

Answer 3

Little modification to your query, assuming you can pick one char which will not be present in MY_STRING, e.g. pipe |
with test as
(select '12 3,456,,,,abc,def' MY_STRING from dual)
select trim('|' from regexp_substr(regexp_replace(MY_STRING,',,',',|,|'),'[^,]+',1,level)) SPLIT
from test
connect by level <= length (regexp_replace(MY_STRING, '[^,]+')) + 1;
Output:
SPLIT
-----------------------
12 3
456
(null)
(null)
(null)
abc
def

Answer 4

No need of PL/SQL, you could do it in plain SQL. See Split comma delimited strings in a table in Oracle.
Using MODEL clause:
WITH sample_data AS (
SELECT '12 3,456,,,,,abc,def' str FROM dual
)
-- end of sample_data mimicking real table
,
model_param AS (
SELECT str AS orig_str ,
','
|| str
|| ',' AS mod_str ,
1 AS start_pos ,
Length(str) AS end_pos ,
(LENGTH(str) -
LENGTH(REPLACE(str, ','))) + 1 AS element_count ,
0 AS element_no ,
ROWNUM AS rn
FROM sample_data )
SELECT trim(Substr(mod_str, start_pos, end_pos-start_pos)) str
FROM (
SELECT *
FROM model_param
MODEL PARTITION BY ( rn, orig_str, mod_str)
DIMENSION BY (element_no)
MEASURES (start_pos, end_pos, element_count)
RULES ITERATE (2000)
UNTIL (ITERATION_NUMBER+1 = element_count[0])
( start_pos[ITERATION_NUMBER+1] =
instr(cv(mod_str), ',', 1, cv(element_no)) + 1,
end_pos[ITERATION_NUMBER+1] =
instr(cv(mod_str), ',', 1, cv(element_no) + 1) )
)
WHERE element_no != 0
ORDER BY mod_str ,
element_no
/
Output
STR
----------------------
12 3
456
abc
def
8 rows selected.
If you want to do it in PL/SQL, then you could use a pipelined table function:
SQL> CREATE OR REPLACE TYPE test_type
2 AS
3 TABLE OF VARCHAR2(100)
4 /
Type created.
SQL> CREATE OR REPLACE FUNCTION comma_to_table(
2 p_list IN VARCHAR2)
3 RETURN test_type PIPELINED
4 AS
5 l_string LONG := p_list || ',';
6 l_comma_index PLS_INTEGER;
7 l_index PLS_INTEGER := 1;
8 BEGIN
9 LOOP
10 l_comma_index := INSTR(l_string, ',', l_index);
11 EXIT
12 WHEN l_comma_index = 0;
13 PIPE ROW ( TRIM(SUBSTR(l_string, l_index, l_comma_index - l_index)));
14 l_index := l_comma_index + 1;
15 END LOOP;
16 RETURN;
17 END comma_to_table;
18 /
Function created.
Let's see the output:
SQL> SELECT *
2 FROM TABLE(comma_to_table('12 3,456,,,,,abc,def'))
3 /
COLUMN_VALUE
------------------------------------------------------------------------------
12 3
456
abc
def
8 rows selected.
SQL>