我想通过这样做来获得计数 join 有了这两张table，我正在做什么 group by 以及 left join .
但是如果那条记录与另一个表不匹配，我就不会得到所有的行。
在给定的查询中：

create table UserTable (
  Id integer not null,
  Name varchar(12) not null
);

insert into UserTable  values (1,  'A B');
insert into UserTable  values (2,  'A C');
insert into UserTable  values (3,  'A C A C');
insert into UserTable  values (4,  'A C C');
insert into UserTable  values (5,  'A C B');
insert into UserTable  values (6,  'A C C');
insert into UserTable  values (7,  'A C D');
insert into UserTable  values (8,  'A C E');
insert into UserTable  values (9,  'A C F');

create table LogTable (
  LogId integer not null,
  Username varchar(12) not null,
  Event varchar(12) not null
);

insert into LogTable  values (1, 'A C A C', 'Read');
insert into LogTable  values (2, 'A C F', 'Write');
insert into LogTable  values (3, 'A C F', 'Read');
insert into LogTable  values (4, 'A C C', 'Update');
insert into LogTable  values (5,'A C C', 'Read');
insert into LogTable  values (6,'A C F', 'Read');
insert into LogTable  values (7,'A C F', 'Update');
insert into LogTable  values (7,'A C F', 'Write');
insert into LogTable  values (7,'A C E','Update');
insert into LogTable  values (7,'A C F', 'Delete');
insert into LogTable  values (10,'A C B', 'Delete');
insert into LogTable  values (11, 'A C F','Copy');
insert into LogTable  values (12, 'A C B','Read');
insert into LogTable  values (13, 'A C F','Update');
insert into LogTable  values (14, 'A C F','Copy');
insert into LogTable  values (15, 'A C F','Read');
insert into LogTable  values (16, 'A C F','Update');
insert into LogTable  values (17, 'A C F','Copy');
insert into LogTable  values (18, 'A C C','Read');
insert into LogTable  values (19, 'A C D','Update');

我在做：

SELECT COUNT(*) as Read,UT.Name, UT.Id 
FROM UserTable UT 
LEFT JOIN LogTable LT ON LT.Username = UT.Name 
WHERE LT.Event = 'Read'
GROUP by UT.Name, UT.Id

我要的是从 UserTable ，如果在 LogTable 如果不存在 ReadCount 作为0。
为什么在这个查询中没有从usertable返回所有记录？
期望输出：

Id  |   Name    |   ReadCount
-----------------------------
1   |   A B     |   0
2   |   A C     |   0
3   |   A C A C |   1
4   |   A C C   |   2
5   |   A C B   |   1
6   |   A C C   |   2
7   |   A C D   |   0
8   |   A C E   |   0
9   |   A C F   |   3