Parsing pipe delimited string into columns?

问题

I have a column with pipe separated values such as:

'23|12.1| 450|30|9|78|82.5|92.1|120|185|52|11'

I want to parse this column to fill a table with 12 corresponding columns: month1, month2, month3...month12.

So month1 will have the value 23, month2 the value 12.1 etc...

Is there a way to parse it by a loop or delimeter instead of having to separate one value at a time using substr?

Thanks.

回答1:

You can use regexp_substr (10g+):

SQL> SELECT regexp_substr('23|12.1| 450|30|9|', '[^|]+', 1, 1) c1,
  2         regexp_substr('23|12.1| 450|30|9|', '[^|]+', 1, 2) c2,
  3         regexp_substr('23|12.1| 450|30|9|', '[^|]+', 1, 3) c3
  4    FROM dual;

C1 C2   C3
-- ---- ----
23 12.1  450

With a loop in PL/SQL:

SQL> SET SERVEROUTPUT ON
SQL> DECLARE
  2     p_tsv  VARCHAR2(1000) := '23|12.1| 450|30|9|78|82.5|92.1|120|185|52|11';
  3     l_item VARCHAR2(100);
  4  BEGIN
  5     FOR i IN 1 .. length(p_tsv) - length(REPLACE(p_tsv, '|', '')) + 1 LOOP
  6        l_item := regexp_substr(p_tsv, '[^|]+', 1, i);
  7        dbms_output.put_line(l_item);
  8     END LOOP;
  9  END;
 10  /

23
12.1
450
30
9
78
82.5
92.1
120
185
52
11

PL/SQL procedure successfully completed

Update

You only have 12 columns, I would write the query direcly without a loop, it will be more performant and easier to maintain than dynamic SQL (not to mention infinitely easier to write):

INSERT INTO your_table
   (ID, month1, month2, month3...)
   SELECT :p_id, 
          regexp_substr(:p_tsv, '[^|]+', 1, 1) c1, 
          regexp_substr(:p_tsv, '[^|]+', 1, 2) c2,
          regexp_substr(:p_tsv, '[^|]+', 1, 3) c3
          ...
     FROM dual;

回答2:

I don't think there's something already defined.

There are few implementations at orafaq and I found this also.

回答3:

I had 99 problems So I used regular expressions Now I have 100 problems hahahahahahaha just concatenate the delim onto beginning & end of string

pure sql solution:

set define on
undefine string
undefine delim
undefine nth
accept string prompt 'Enter the string: '
accept delim prompt 'Enter the delimiter: '
accept nth prompt 'Enter nth: '
select '&&string' as string,
       '&&delim' as delimiter, 
        &&nth||decode(&&nth,1,'st',2,'nd',3,'rd','th') as nth,
 substr('&&delim'||'&&string'||'&delim',
        instr('&&delim'||'&&string'||'&&delim', '&&delim', 1, &&nth ) + length('&&delim'),
        instr('&&delim'||'&&string'||'&&delim', '&&delim', 1, &&nth + 1 ) - instr('&&delim'||'&&string'||'&&delim', '&&delim', 1, &&nth ) - length('&&delim')
       ) as val from dual

来源：https://stackoverflow.com/questions/2942052/parsing-pipe-delimited-string-into-columns

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Oracle

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