Convert comma separated string to array in PL/SQL

Question

How do I convert a comma separated string to a array?

I have the input \'1,2,3\' , and I need to convert it into an array.

Answer 1

I know Stack Overflow frowns on pasting URLs without explanations, but this particular page has a few really good options:

http://www.oratechinfo.co.uk/delimited_lists_to_collections.html

I particularly like this one, which converts the delimited list into a temporary table you can run queries against:

/* Create the output TYPE, here using a VARCHAR2(100) nested table type */

SQL> CREATE TYPE test_type AS TABLE OF VARCHAR2(100);
  2  /

Type created.

/* Now, create the function.*/

SQL> CREATE OR REPLACE FUNCTION f_convert(p_list IN VARCHAR2)
  2    RETURN test_type
  3  AS
  4    l_string       VARCHAR2(32767) := p_list || ',';
  5    l_comma_index  PLS_INTEGER;
  6    l_index        PLS_INTEGER := 1;
  7    l_tab          test_type := test_type();
  8  BEGIN
  9    LOOP
 10      l_comma_index := INSTR(l_string, ',', l_index);
 11      EXIT WHEN l_comma_index = 0;
 12      l_tab.EXTEND;
 13      l_tab(l_tab.COUNT) := SUBSTR(l_string, l_index, l_comma_index - l_index);
 14      l_index := l_comma_index + 1;
 15    END LOOP;
 16    RETURN l_tab;
 17  END f_convert;
 18  /

Function created.

---

/* Prove it works */

SQL> SELECT * FROM TABLE(f_convert('AAA,BBB,CCC,D'));

COLUMN_VALUE
--------------------------------------------------------------------------------
AAA
BBB
CCC
D

4 rows selected.