oracle字符串拼接更新,oracle 使用拼接字符串更新表

//数据

ta

col_1 col_2

-----------

a

b

c

d

//结果：

col_1 col_2

-----------

a z0001

b z0002

c z0003

d z0004

//

create table ta(

col_1 varchar2(2),

col_2 varchar2(7))

/

insert into ta

select 'a','' from dual union all

select 'b','' from dual union all

select 'c','' from dual union all

select 'd','' from dual

/

//解法一：

declare

rn number :=0;

begin

for cl in (select col_1 from ta order by col_1) loop

rn :=rn+1;

update ta

set col_2='z'||lpad(rn,4,'0')

where col_1=cl.col_1;

commit;

end loop;

end;

/

//将表还原为原来的状态：

update ta

set col_2=''

where col_1 in ('a','b','c','d');//col_1 is not null;

//解法二：

begin

for c in (select rowid rid,

row_number() over (order by col_1) rn

from ta)

loop

update ta

set col_2='z000'||c.rn

where rowid=c.rid;

end loop;

commit;

end;

/

//解法三：

create table tb as

select * from ta where 1=0

/

insert into tb

select col_1,'z000'||rn

from (

select rownum rn,ta.col_1 col_1

from ta)

/