我有一个目前是CLOB的列(COMMENTS)。有没有办法可以将COMMENTS CLOB列拆分为oracle SQL中的单独(4k)VARCHAR2列?
提前致谢
以下是我的尝试:
create or replace procedure longsubstr(p_rowid in rowid,
comment in comment)
return varchar2
as l_tmp long;
begin
select COMMENT into l_tmp from table_name
where rowid = p_rowid;
return substr(l_tmp, p_form, p_for);
end;
/
答案 0 :(得分:2)
SELECT DBMS_LOB.SUBSTR( t.comments, 4000, l.COLUMN_VALUE )
FROM table_name t
CROSS JOIN
TABLE(
CAST(
MULTISET(
SELECT LEVEL * 4000 - 3999
FROM DUAL
CONNECT BY LEVEL * 4000 - 3999 <= DBMS_LOB.GETLENGTH( t.comments )
) AS SYS.ODCINUMBERLIST
)
) l
或
WITH positions ( comments, pos ) AS (
SELECT comments,
1
FROM table_name
UNION ALL
SELECT comments,
pos + 4000
FROM positions
WHERE pos + 4000 <= DBMS_LOB.GETLENGTH( comments )
)
SELECT DBMS_LOB.SUBSTR( comments, 4000, pos ) AS split_comment
FROM positions
答案 1 :(得分:1)
您可以使用
dbms_lob.substr( clob_column, for_how_many_bytes, from_which_byte )
功能
为此:
declare
type typ_comment is table of varchar2(4000);
v_varchar typ_comment := typ_comment();
v_clob table_name.comments%type;
k number;
j number := 4000;
begin
select comments into v_clob from table_name where rowid = '&p_rowid'; -- like AAAS9BAAEAAAAEeAAA without quotation
k := ceil(dbms_lob.getlength(v_clob)/j);
v_varchar.extend(k);
for i in 1..k
loop
v_varchar(i):= dbms_lob.substr( v_clob, j, 1 + j * ( i - 1 ) );
end loop;
end;