Drop tables from USERS tablesapce

Question

Hello,
I am newbie to Oracle
1) I want to DROP all tables we created except from those that begins with QNT letters. I tried
BEGIN
FOR T IN (SELECT TABLE_NAME FROM USER_TABLES)
LOOP
EXECUTE IMMEDIATE ('DROP TABLE MyUserName.' || T.TABLE_NAME);
END LOOP;
END;
but I get error
ORA-00933: SQL command not properly ended
or when changing line 4
EXECUTE IMMEDIATE ('DROP TABLE ' || T.TABLE_NAME);
I get
ORA-00903: Invalid table name
What's the problem? How Can I ignore QNTxxxx tables?
2) In addition, I get error when log in to Oracle Schema Manager (though, I log in successfully to SQL WorkSheet)
MGR-02150: an unrecognized database version was encountered.
why?
The server app is 10g, and my computer client app is 8.0.5
Your help will be appreciated,
Ori

Answer 1

note: I made little change: 'Q' instead of 'QNT'
On sql plus i got error
ERROR at line 1:
ORA-06550: line 2, column 0:
PLS-00103: Encountered the symbol "end-of-file" when expecting one of the following:
:= . ( @ % ;
And on sql worksheet the result is:
SQLWKS> DECLARE v_sql VARCHAR2(50);
2> BEGIN FOR t IN ( SELECT table_name FROM user_tables WHERE SUBSTR(table_name,1,1) <> 'Q' ) LOOP v_sql := 'drop table ' || t.table_name;
3> EXECUTE IMMEDIATE v_sql;
4> END LOOP;
5> EXCEPTION WHEN OTHERS THEN RAISE_APPLICATION_ERROR ( -20000 , 'Error executing command:' || CHR(10) || v_sql , TRUE );
6> END;
7>
ORA-20000: Error executing command:
drop table Table1
ORA-06512: at line 5
ORA-00942: table or view does not exist