Oracle 18c

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CREATE TYPE indexed_string AS OBJECT(
  column_id NUMBER,
  value     NVARCHAR2(4000)
);
CREATE TYPE indexed_string_list AS TABLE OF indexed_string;
CREATE OR REPLACE FUNCTION split_String(
  i_str    IN  NVARCHAR2,
  i_delim  IN  NVARCHAR2 DEFAULT ','
) RETURN indexed_string_list PIPELINED DETERMINISTIC
AS
  p_index        PLS_INTEGER := 0;
  p_start        NUMBER(5) := 1;
  p_end          NUMBER(5);
  c_len CONSTANT NUMBER(5) := LENGTH( i_str );
  c_ld  CONSTANT NUMBER(5) := LENGTH( i_delim );
BEGIN
  IF c_len > 0 THEN
    p_end := INSTR( i_str, i_delim, p_start );
    WHILE p_end > 0 LOOP
      p_index := p_index + 1;
      PIPE ROW (
        indexed_string(
          p_index,
          SUBSTR( i_str, p_start, p_end - p_start )
        )
      );
      p_start := p_end + c_ld;
      p_end := INSTR( i_str, i_delim, p_start );
    END LOOP;
    IF p_start <= c_len + 1 THEN
      p_index := p_index + 1;
      PIPE ROW (
        indexed_string(
          p_index,
          SUBSTR( i_str, p_start, c_len - p_start + 1 )
        )
      );
    END IF;
  END IF;
END;
/
SELECT * FROM USER_ERRORS;
SELECT *
FROM   TABLE(split_string(N'abc\def\\ghi\jkl', '\'))


COLUMN_ID
VALUE


1
abc

2
def

3
null

4
ghi

5
jkl