PL/SQL 语句
添加图书，如果数据库里有该图书信息，就把库存量增加， 如果没有就新增加条目
这个语句怎么写？？

[解决办法]

SQL code

merge into a using bon (a.a=b.b)when matched then update xxxxxwhen not matched then insert (xxx) values(xxx);
[解决办法]
declare
  vi number :=0;
  v_rowid varchar2(18);
begin
 begin
   select t.rowid  
   into v_rowid
   from tablexxx t
   where t.idxx = 'xxxid';
 exception
   when others then
     v_rowid := '';
 end;
 if v_rowid is null then
   insert into xxx......;
 else  
   update tablexxx t
   set  ......
   where t.rowid = v_rowid;
 end if;
exception
 when others then
   null;
end;