删除用户，创建用户命令
drop user goda cascade；删除用户及其下所有对象，包括表
CREATE USER qdcenter
IDENTIFIED BY qdcenter
DEFAULT TABLESPACE data1
TEMPORARY TABLESPACE temp1
QUOTA unlimited ON data1
QUOTA unlimited ON temp1
QUOTA unlimited ON idx1
QUOTA unlimited ON rbs1
QUOTA 10M ON system;
GRANT DBA TO qdcenter;
grant create table to qdcenter;
grant insert any table to qdcenter;
grant select any table to qdcenter;
grant update any table to qdcenter;
grant delete any table to qdcenter;
grant create any view to qdcenter;
grant drop any view to qdcenter;
grant alter any sequence to qdcenter;
grant create any sequence to qdcenter;
grant select any sequence to qdcenter;
grant drop any sequence to qdcenter;
grant create public synonym to qdcenter;
grant create any synonym to qdcenter;
grant drop public synonym to qdcenter;
grant drop any synonym to qdcenter;