CODEWITHSUNDEEP
sqloracle-databasecsvplsql
Hooplator15
Hooplator15

Reputation: 1550

PL SQL - How to loop results of splitting a csv string?

So I have a string 

test = 'a,b,c,d';

I want to split this string up into each word deliminated by a comma. Then I want to loop the results.

I have seen this solution:

WITH t AS
( SELECT 'a,b,c,d,e' AS txt FROM dual
)
SELECT CAST(REGEXP_SUBSTR (txt, '[^,]+', 1, level) AS CHAR(12))
FROM t
CONNECT BY level <= LENGTH(regexp_replace(txt,'[^,]*'))+1;

However, it does not allow me to loop the result set. I have additional processing that needs to be done with each substring.

How can I go about looping this result set?

Upvotes: 1

Views: 1014

Answers (1)

MT0
MT0

Reputation: 167811

You can just use an inline view with your query:

WITH t AS (
  SELECT 'a,b,c,d,e' AS txt FROM dual
)
SELECT extra_processing( value )
FROM   (
  SELECT CAST(REGEXP_SUBSTR (txt, '[^,]+', 1, level) AS CHAR(12)) AS value
  FROM t
  CONNECT BY level <= LENGTH(regexp_replace(txt,'[^,]*'))+1
);

Since this is tagged with PL/SQL - why use SQL at all:

Oracle Setup:

A small helper function to split a string on a delimiter:

CREATE OR REPLACE FUNCTION split_String(
  i_str    IN  VARCHAR2,
  i_delim  IN  VARCHAR2 DEFAULT ','
) RETURN SYS.ODCIVARCHAR2LIST DETERMINISTIC
AS
  p_result       SYS.ODCIVARCHAR2LIST := SYS.ODCIVARCHAR2LIST();
  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_result.EXTEND;
      p_result( p_result.COUNT ) := 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_result.EXTEND;
      p_result( p_result.COUNT ) := SUBSTR( i_str, p_start, c_len - p_start + 1 );
    END IF;
  END IF;
  RETURN p_result;
END;
/

Code:

DECLARE
  list SYS.ODCIVARCHAR2LIST := split_String( 'a,b,c,d,e' );
BEGIN
  FOR i IN 1 .. list.LAST LOOP
    -- do your extra processing
  END LOOP;
END;
/

or you can just do it in SQL:

SELECT extra_processing( COLUMN_VALUE )
FROM   TABLE( split_String( 'a,b,c,d,e' ) )

(Note: COLUMN_VALUE is the column name Oracle gives to values generated by the TABLE operator.)

Upvotes: 2

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