using long string(over 4000) in oracle query
I know that in sql varchar2 can only be around 4000.
I know that in oracle PL varchcar2 can be around 32000.
I have a varchar2 variable defined that is over 4000 characters long and I want to use it in a query. I don't want to insert the value into a table. The value is a dilimited string that I am parsing and inserting into a table with this query. This query works when the variable is less than 4000 characters long. Is there a way to make it work with up to 32000 characters?
create global temporary table t(single_element varchar(500),element_no number);
declare
--declared as 32767 but this string contains less than 4000 characters.
--This will work. If you expand the string to 32000 characters it will not work.
myvar varchar2(32767) := 'tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4^~tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testmsg4';
begin
delete from t;
insert into t
SELECT SUBSTR(str, start_pos, (next_pos-start_pos)) AS single_element, element_no
FROM (
SELECT
ilv.str,
nt.column_value AS element_no,
INSTR(ilv.str, '^~', DECODE(nt.column_value, 1, 0, 1), DECODE(nt.column_value, 1, 1, nt.column_value-1)) + 2 AS start_pos,
INSTR(ilv.str, '^~', 1, DECODE(nt.column_value, 1, 1, nt.column_value)) AS next_pos
FROM (
select '~' || myvar || '^~' as str,
(Length(myvar) - length(replace(myvar,'^~','')))/2 + 2 as no_of_elements
from dual) ilv,
TABLE(
CAST(
MULTISET(
SELECT ROWNUM FROM dual CONNECT BY ROWNUM < ilv.no_of_elements
) AS number_ntt )) nt
);
end;
The error I get when expanding "myvar" to 32000 characters is
can bind a LONG value only for insert into a LONG column
Is there a way I can get around this size restraint because i'm not actually inserting this value into a table, i'm just using it in the query?
Answer
Do you have to define the variable as a VARCHAR2? Could you define it as a CLOB instead?
If I change the declaration of MYVAR from a VARCHAR2(32767) to a CLOB and define the NUMBER_NTT type, your code runs for me
SQL> ed
Wrote file afiedt.buf
SP2-0161: line 2 truncated.
1 declare
2 myvar clob := 'tcd1~#testmsg1^~tcd2~#testmsg2^~tcd3~#testmsg3^~tcd4~#testms
<<snip>>
~tcd3~#testmsg3^~tcd4~#testmsg4';
4 begin
5 delete from t;
6 insert into t
7 SELECT SUBSTR(str, start_pos, (next_pos-start_pos)) AS single_element, elem
ent_no
8 FROM (
9 SELECT
10 ilv.str,
11 nt.column_value AS element_no,
12 INSTR(ilv.str, '^~', DECODE(nt.column_value, 1, 0, 1), DECODE
(nt.column_value, 1, 1, nt.column_value-1)) + 2 AS start_pos,
13 INSTR(ilv.str, '^~', 1, DECODE(nt.column_value, 1, 1, nt.colu
mn_value)) AS next_pos
14 FROM (
15 select '~' || myvar || '^~' as str,
16 (Length(myvar) - length(replace(myvar,'^~','')))/2 + 2 as n
o_of_elements
17 from dual) ilv,
18 TABLE(
19 CAST(
20 MULTISET(
21 SELECT ROWNUM FROM dual CONNECT BY ROWNUM < ilv.n
o_of_elements
22 ) AS number_ntt )) nt
23 );
24* end;
25 /
PL/SQL procedure successfully completed.
SQL> select count(*) from t;
COUNT(*)
----------
172
That being said, that's not how I'd parse a delimited string, particularly in PL/SQL. But it does the job.