关于ORACLE的问题，是不是ORACLE的一个BUG？

悬赏园豆：100 [待解决问题]

环境：oracle11g，PLSQL9.0

1.不加条件查询结果

2.添加MOTYPE = '16'的条件查询结果

3.添加MOTYPE = '11'的查询结果

说明：从1中我们可以看出，有两条符合MOTYPE = '16'的数据，但是我们添加条件查询不到数据，有两条符合MOTYPE = '11'，添加查询条件后可以查到，所以，遇到的问题是为什么MOTYPE = '16'查不到数据？

分析：其中符合MOTYPE = '16'的两条数据的特点是TBLNaturalOrderQty有，但是TBLWHMOCOEFFICIENT没有，这两张表用 full join进行连接。

求大牛帮我分析一下原因是为什么,非常感谢。

-- Create table
create table TBLNATURALORDERQTY
(
  yearmonth       VARCHAR2(40) not null,
  motype          VARCHAR2(40) not null,
  orgid           VARCHAR2(40),
  naturalorderqty NUMBER(22,2)
)
tablespace FHDEMO
  pctfree 10
  initrans 1
  maxtrans 255
  storage
  (
    initial 64
    next 8
    minextents 1
    maxextents unlimited
  );
-- Add comments to the columns 
comment on column TBLNATURALORDERQTY.yearmonth
  is '年月';
comment on column TBLNATURALORDERQTY.motype
  is '工单类型';
comment on column TBLNATURALORDERQTY.orgid
  is '组织代码';
comment on column TBLNATURALORDERQTY.naturalorderqty
  is '自然订单量';


-- Create table
create table TBLWHMOCOEFFICIENT
(
  motype      VARCHAR2(40) not null,
  coefficient NUMBER(22,10) not null,
  muser       VARCHAR2(40) not null,
  mdate       NUMBER(8) not null,
  mtime       NUMBER(6) not null
)
tablespace FHDEMO
  pctfree 10
  initrans 1
  maxtrans 255
  storage
  (
    initial 64
    next 1
    minextents 1
    maxextents unlimited
  );
-- Create/Recreate primary, unique and foreign key constraints 
alter table TBLWHMOCOEFFICIENT
  add constraint TBLWHMOCOEFFICIENT_PK primary key (MOTYPE)
  using index 
  tablespace FHDEMO
  pctfree 10
  initrans 2
  maxtrans 255
  storage
  (
    initial 64K
    next 1M
    minextents 1
    maxextents unlimited
  );

建表脚本

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('12', 1.0000000000, '0211001888', 20151210, 145319);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('77', 3.0200000000, 'ADMIN', 20151203, 113907);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('78', 3.3300000000, 'ADMIN', 20151203, 114033);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('99', 1.2500000000, 'ADMIN', 20151207, 134046);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('50', 2.0900000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('11', 0.1500000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('14', 0.9600000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('15', 0.6400000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('18', 0.1000000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('19', 0.2400000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('20', 0.4100000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('51', 2.0900000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('52', 0.7600000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('53', 0.2000000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('56', 4.9900000000, 'ADMIN', 20151105, 120000);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('70', 4.0400000000, 'ADMIN', 20151206, 231146);

insert into TBLWHMOCOEFFICIENT (MOTYPE, COEFFICIENT, MUSER, MDATE, MTIME)
values ('79', 3.3230000000, 'ADMIN', 20151203, 114434);

第一张表数据脚本

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201511', '11', '100', 300.00);

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201511', '12', '100', 350.00);

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201511', '15', '100', 200.00);

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201511', '16', '100', 250.00);

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201511', '50', '100', 100.00);

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201510', '11', '100', 2000.00);

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201510', '12', '100', 2500.00);

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201510', '15', '100', 3000.00);

insert into TBLNaturalOrderQty (YEARMONTH, MOTYPE, ORGID, NATURALORDERQTY)
values ('201510', '16', '100', 3500.00);