在oracle中，可以利用drop语句删除schema，语法为“drop user username cascade;”；drop语句用于删除表的结构，包括schema，schema是数据库对象的集合，也可以理解为用户。

本教程操作环境：Windows10系统、Oracle 11g版、Dell G3电脑。

oracle怎么删除schema

删除schema语法如下：

drop user username cascade;

示例如下：

1)查看用户的默认表空间及临时表空间

set lines 300
col username for a30
select username ,default_tablespace,TEMPORARY_TABLESPACE from dba_users where username='MESPRD';
-----------------------------------
USERNAME   DEFAULT_TABLESPACE     TEMPORAR    Y_TABLESPACE
MESPRD    HTTBS_MESPRD                        TEMP

2)查看该用户的权限和角色

select privilege from dba_sys_privs where grantee='SYSADM'
union
select privilege from dba_sys_privs where grantee in (select granted_role from dba_role_privs where grantee='MESPRD' );
-----------------------------------
PRIVILEGE
CREATE CLUSTER
CREATE INDEXTYPE
CREATE OPERATOR
CREATE PROCEDURE
CREATE SEQUENCE
CREATE SESSION
CREATE TABLE
CREATE TRIGGER
CREATE TYPE

已选择9行。

3)获取获得授予用户权限的脚本

select 'grant '||privilege||' to SYSADM;' from (select privilege from dba_sys_privs where grantee='SYSADM'
union
select privilege from dba_sys_privs where grantee in (select granted_role from dba_role_privs where grantee='SYSADM' ));

4)执行脚本获得删除该schema下对象的脚本 mesprd为要删除的schema

connect mesprd/MESPRD
spool E:\app\Administrator\del_mesprd.sql;
select 'alter table '||table_name||' drop constraint '||constraint_name||' ;' from user_constraints where constraint_type='R';
select 'truncate table '||table_name ||';' from user_tables;
select 'drop table '||table_name ||' purge;' from user_tables;
select 'drop index '||index_name ||';' from user_indexes;
select 'drop view ' ||view_name||';' from user_views;
select 'drop sequence ' ||sequence_name||';' from user_sequences;
select 'drop function ' ||object_name||';'  from user_objects  where object_type='FUNCTION';
select 'drop procedure '||object_name||';' from user_objects  where object_type='PROCEDURE';
select 'drop package '|| object_name||';' from user_objects  where object_type='PACKAGE';
select 'drop database link '|| object_name||';' from user_objects  where object_type='DATABASE LINK';
spool off;

5)sqlplus连接到该schema下，执行如上获得的脚本

执行前查看下该schema下的对象，执行后再次查看下该schema下的对象

@？\E:\app\Administrator\del_mesprd.sql;
SQL> select object_type,count(*) from user_objects group by object_type;

6)kill掉连接数据库的session

select 'alter system kill session '''||sid||','||serial#||''' immediate;' from v$session where username='MESPRD';

7)删除该schema

drop user MESPRD cascade;