oracle查询锁表及解锁,修改表字段名与复制表结构和数据的方法

select count(*) from v$locked_ ;
select * from v$locked_ ;

select b.owner,b. _name,a.session_id,a.locked_mode from v$locked_  a,dba_ s b where b. _id = a. _id;

select b.username,b.sid,b.serial#,logon_time from v$locked_  a,v$session b where a.session_id = b.sid order by b.logon_time; 

alter table tb modify (name nvarchar2(20));

alter table sft_bfwo rename column bfwoid to wid;
alter table sft_bfwo add bfwoid char(16);
update sft_bfwo set bfwoid=trim(wid);
alter table sft_bfwo drop column wid;

create table table_name_new as select * from table_name_old

create table table_name_new as select * from table_name_old where 1=2;

create table table_name_new like table_name_old

insert into table_name_new select * from table_name_old

insert into table_name_new(column1,column2...) select column1,column2... from table_name_old