急求得到记录条数SQL语句！

Question

有两个表Table A、Table B是有联系的，如下图
我现在要得到的结果如Result所示
请问如何写SQL语句？
--------------------------------
Table ANAME_ID     Record_A Record_B
1     aaa         xxx
1     bbb         yyy
1     ccc
2     ddd         zzz
2         qqq
3         ttt
4     eee         iii
4     fff         mmm
5     ggg         nnn
5
5     hhh
…     …          …--------------------------------
Table BNAME_ID     NAME
1     namea
2     nameb
3     namec
4     named
5     namee
…     …
--------------------------------
ResultNAME Record_Num_A Record_Num_B
namea     3             2
nameb     1             2
namec     0             1
named     2             2
namee     2             1
…     …              …

Answer 1

-------------------------------- 
Table   A NAME_ID   Record_A         Record_B 
1         aaa                 xxx 
1         bbb                 yyy 
1         ccc 
2         ddd                 zzz 
2                             qqq 
3                             ttt 
4         eee                 iii 
4         fff                 mmm 
5         ggg                 nnn 
5 
5         hhh 
…          …                     … -------------------------------- 
Table   B NAME_ID         NAME 
1              namea 
2              nameb 
3              namec 
4              named 
5              namee 
…                … 
-------------------------------- 
Result NAME      Record_Num_A              Record_Num_B 
namea         3                         2 
nameb         1                         2 
namec         0                         1 
named         2                         2 
namee         2                         1 
…              …                           … 

Answer 2

好像直接Group by就可以出来结果SQL> create table ta(
  2    name_id int,
  3    record_A nvarchar2(20),
  4    record_B nvarchar2(20)
  5  );Table createdSQL> create table tb(
  2    name_id int,
  3    name nvarchar2(20)
  4  );Table createdSQL> insert into ta
  2  select 1,'aaa','xxx' from dual
  3  union
  4  select 1,'bbb','yyy' from dual
  5  union
  6  select 1,'ccc',null from dual
  7  union
  8  select 2,'ddd','zzz' from dual;4 rows insertedSQL> insert into tb
  2  select 1,'namea' from dual
  3  union
  4  select 2,'nameb' from dual;2 rows insertedSQL> select b.name,count(a.record_a),count(a.record_b) from ta a
  2  inner join tb b on a.name_id=b.name_id
  3  group by b.name;NAME                                     COUNT(A.RECORD_A) COUNT(A.RECORD_B)
---------------------------------------- ----------------- -----------------
namea                                                    3                 2
nameb                                                    1                 1

Answer 3

使用Count函数的时候，COUNT(*)的时候，包括NULL的行
COUNT(字段名)は、不包括NULL的行。是不是疑惑这个？

Answer 4

select name,nvl(sum_record_A,0),nvl(sum_record_B,0) from (
select name,sum_record_A,sum_record_B from Tbl_z_b
left join (
select name_id, count(record_A) sum_record_A,count(record_B) sum_record_B from tbl_z_a  
where exists(select 1 from Tbl_z_b where Tbl_z_b.name_id = tbl_z_a.name_id)
group by name_id
) tbl_test on Tbl_z_b.name_id=tbl_test.name_id)