oracle 主键自增函数

1、创建一个function 函数 ，参数分别是“表名”和“自增列明”

函数如下：

create or replace function auto_nid(tab_name in varchar2,sell in varchar2) return varchar2
is
inx varchar2(20);
iny number;
inz number;
revalues varchar2(20);
v_sql varchar2(4000);
begin
inx:=1;
inz:=1;
v_sql:='select count(1) from ' || tab_name ;
execute immediate v_sql into iny;
if (iny is null or iny=0 ) then
  return '1';
else
  while to_number(inx)<=iny loop
  begin
    v_sql:='select max(to_number('||sell||')) from ' ||tab_name;
    execute immediate v_sql into inz;
      if inz>0 then
           inx:=to_number(inz)+1;
           revalues:=inx;
      else
           exit;
      end if;
  end;
  end loop;
end if;
return revalues;
end;

 

2、调用方法

 

 insert into table_name  values (auto_nid('table_name','table_id')');