一个字段值作为另一张表名，怎么查询？

[yaku2688]

有一张表A，里面有id,name其中name值记录这一些表的表名，如表c,表d,表e的表名

请问如何根据表A中id查询出表c的内容。

此种语句
select * from (select name from A where id='...');
就不用说了，不正确。

[yaku2688]

看来只能用存储过程，本来意思是不用的。

[sinpoal]

--用动态sql写
declare 
table_name varchar(10);
sql_statement varchar2(100)
begin
select name into table_name from where id=&v_id;
sql_statement:='select * from '||table_name;
execute immediate sql_statement;
end;

[gelyon]

你要采用动态SQL去做。

[yaku2688]

楼上能说细点吗？

[minitoy]

先select name into 变量 from tablea;
然后open cursorname for'select * from '||变量;

[caofaping]

create table a (
       name varchar2(20)
);
insert into a(name) values ('a_test');
commit;

create or replace procedure create_table as
table_name varchar2(100);
begin
  select t.name into table_name from a t;
  execute immediate 'select * from ' || table_name; --动态SQL

end create_table;

[minitoy]

Connected to Oracle Database 10g Enterprise Edition Release 10.1.0.2.0 
Connected as scott
 
SQL> 
SQL> create table tbl_store
  2  (id number(10),
  3   name varchar2(10));
  
 
Table created
 
SQL> insert into tbl_store values(1,'emp');
 
1 row inserted
 
SQL> commit;
 
Commit complete
 
SQL> set serveroutput on
SQL> 
SQL>     declare
  2      cv_emp sys_refcursor;
  3      v_table varchar2(10);
  4      begin
  5      select name into v_table from tbl_store where rownum=1;
  6      open cv_emp for 'select ename from '||v_table;
  7      loop
  8      fetch cv_emp into v_table ;
  9      exit when cv_emp%notfound;
 10      dbms_output.put_line(v_table);
 11      end loop;
 12      close cv_emp;
 13      end;
 14  /
 
SMITH
ALLEN
WARD
JONES
MARTIN
BLAKE
CLARK
SCOTT
KING
TURNER
ADAMS
JAMES
FORD
MILLER
 
PL/SQL procedure successfully completed
 
SQL> 

[心中的彩虹]

[Quote=引用楼主 yaku2688 的回复:]
有一张表A，里面有id,name其中name值记录这一些表的表名，如表c,表d,表e的表名

请问如何根据表A中id查询出表c的内容。

此种语句
select * from (select name from A where id='...');
就不用说了，不正确。
[/Quote]

--用动态拼接

SQL> edi
已写入 file afiedt.buf

  1  declare
  2  type cur1_type is ref cursor;
  3  cur1 cur1_type;
  4  v_tb varchar2(40);
  5  v_id varchar2(20);
  6  begin
  7  select tbname into v_tb from t_tab where rownum=1;
  8  open cur1 for 'select id from  '||v_tb;
  9  fetch cur1 into v_id;
 10  while cur1%found loop
 11  dbms_output.put_line(v_id);
 12  fetch cur1 into v_id;
 13  end loop;
 14  close cur1;
 15* end;
SQL> /

PL/SQL 过程已成功完成。

SQL> set serveroutput on
SQL> /
wkc168
2
2
2
2
2
8
test
11
22
44

PL/SQL 过程已成功完成。