Default for clob

Question

Hi friends,
I'm getting the below error when I use where clause in clob field.. mname is a clob field with default ' '
SQL>select * from test where mname=' ';
select * from test where mname=' '
ERROR at line 1:
ORA-00932: inconsistent datatypes: expected - got CLOBThanks a lot

Answer 1

SQL doesn't know how to compare CLOBs. Use DBMS_LOB.COMPARE:
SQL> create table test(
  2                    id number,
  3                    mname clob
  4                   )
  5  /
Table created.
SQL> insert
  2    into test
  3    values(
  4           1,
  5           ' '
  6          )
  7  /
1 row created.
SQL> insert
  2    into test
  3    values(
  4           2,
  5           'abc'
  6          )
  7  /
1 row created.
SQL> select  *
  2    from  test
  3    where mname = ' '
  4  /
  where mname = ' '
ERROR at line 3:
ORA-00932: inconsistent datatypes: expected - got CLOB
SQL> select  *
  2    from  test
  3    where dbms_lob.compare(mname,' ') = 0
  4  /
        ID MNAME
         1SY.
Edited by: Solomon Yakobson on Oct 10, 2012 3:47 PM