仅当表存在时才删除行

declare
    table_name_l    user_tables.table_name%type;
begin
    select table_name into table_name_l from user_tables where table_name = 'TB_FIELD';
    -- if we didn't raise an exception the table must exist 
    execute immediate 'delete from tb_field where id = :1' using '213';

    exception 
        when no_data_found then 
            -- do nothing - table doesn't exist
            null;
end;

最简单的方法是捕获并忽略“table not found”异常:

declare
  l_id number := 12345;
begin
  execute immediate 'delete tb_field where id=:1' using l_id;
exception
  when others then
    if sqlcode != -942 /*table or view does not exist*/ then
      raise;
    end if;
end;
/