Concatenate Blobs ...

Question

Hi,
I have two tables, each of them contain a blob column. My need is to concatenate the content of the two columns and store the new blob content in a new column (in one of the two tables or in an new table).
Can I have help for : from where can I start please ?
Thanks

Answer 1

for me this works just fine:
(tested on 10g XE)
SQL> create table testblob (id number, data blob);
Tabelle wurde erstellt.
SQL> insert into testblob (id, data) values (1, empty_blob());
1 Zeile wurde erstellt.
SQL> insert into testblob (id, data) values (2, empty_blob());
1 Zeile wurde erstellt.
SQL> declare
  2    cursor cr is
  3      select data
  4        from testblob
  5          for update of data nowait;
  6    vcText VARCHAR2(30):='this is a text';
  7  begin
  8    for rec in cr loop
  9      dbms_lob.open(rec.data, dbms_lob.LOB_READWRITE);
10      dbms_lob.write(rec.data, length(vcText), 1, utl_raw.cast_to_raw(vcText));
11      dbms_lob.close(rec.data);
12    end loop;
13  end;
14  /
PL/SQL-Prozedur erfolgreich abgeschlossen.
SQL> select dbms_lob.getlength(data) from testblob;
DBMS_LOB.GETLENGTH(DATA)
                      14
                      14
SQL> declare
  2    cursor cr(i_nId in number) is
  3      select data
  4        from testblob
  5       where id=i_nId
  6          for update of data nowait;
  7    blob1 BLOB;
  8    blob2 BLOB;
  9  begin
10    open cr(1);
11    fetch cr into blob1;
12    close cr;
13    open cr(2);
14    fetch cr into blob2;
15    close cr;
16
17    dbms_lob.open(blob1, dbms_lob.LOB_READWRITE);
18    dbms_lob.append(blob1, blob2);
19    dbms_lob.close(blob1);
20  end;
21  /
PL/SQL-Prozedur erfolgreich abgeschlossen.
SQL> select dbms_lob.getlength(data) from testblob;
DBMS_LOB.GETLENGTH(DATA)
                      28
                      14
SQL>