Query the content of blobs

Question

Dear all,
I have a table containing blobs with only text in there. Now I would like to query the table for records where the blob contains a certain string. However I keep getting a ORA-00932 error message stating “inconsistent datatype; expecting NUMBER got BLOB”
This is the query I use where user_data is the BLOB.
select * from user_defined
where user_data like '%test_account_used%'
order by ENQ_TIME desc
Can anybody please explain what is wrong and what is the correct approach on querying a blob.

Answer 1

Hello,
Look at this:
SQL> desc bin_docs
Name                                      Null?    Type
DOC_ID                                    NOT NULL NUMBER(5)
NAME                                               VARCHAR2(128)
DOC                                                BLOB
SQL>
Declare
  b_lob  blob ;
Begin
  b_lob :=  utl_raw.cast_to_raw('One two three yargla oumbala toto' || lpad( 'x', 20000,'x') ) ;
  insert into bin_docs values (3, 'xx', b_lob ) ;
End ;
SQL> select doc_id, to_char( substr( utl_raw.cast_to_varchar2(doc), 1, 200 ) )
  2  from bin_docs
  3  where to_char( substr( utl_raw.cast_to_varchar2(doc), 1, 200 ) ) like '%yargla oumbala%'
  4  /
    DOC_ID TO_CHAR(SUBSTR(UTL_RAW.CAST_TO_VARCHAR2(DOC),1,200))
         3 One two three yargla oumbala totoxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
SQL> Francois