关于统计的一些查询？

create table question_history(

ID int  primary key identity(1,1) not null,

uID int not null,

questionID int not null,

true smallint not null

)

insert into question_history(uID,questionID,ture) value (123,800456,1)
insert into question_history(uID,questionID,ture) value (123,800456,0)
insert into question_history(uID,questionID,ture) value (123,800456,1)
insert into question_history(uID,questionID,ture) value (123,800123,1)
insert into question_history(uID,questionID,ture) value (123,800123,0)
insert into question_history(uID,questionID,ture) value (456,800456,1)
insert into question_history(uID,questionID,ture) value (456,800123,0)
insert into question_history(uID,questionID,ture) value (456,800123,1)



--查询某用户总做题数（去重）
select count(distinct(questionID)) from question_history
where uID = 123

--查询某用户总作对题数
select count(distinct(questionid)) from question_history
where uID = 123
and true = 1

历史记录数据较多

如果将以上两个查询合并为一个查询


另外一个问题，如果查询出这样的列表出来



uid,total,true
--------------------------
123  5    3
456  3    2

[解决办法]

我知道了 是这样

create table question_history(
 
ID int  primary key identity(1,1) not null,
 
uID int not null,
 
questionID int not null,
 
true smallint not null
 
)
 
insert into question_history(uID,questionID,true) values (123,800456,1)
insert into question_history(uID,questionID,true) values (123,800456,0)
insert into question_history(uID,questionID,true) values (123,800456,1)
insert into question_history(uID,questionID,true) values (123,800123,1)
insert into question_history(uID,questionID,true) values (123,800123,0)
insert into question_history(uID,questionID,true) values (456,800456,1)
insert into question_history(uID,questionID,true) values (456,800123,0)
insert into question_history(uID,questionID,true) values (456,800123,1)

SELECT 
  UID,
  COUNT(DISTINCT questionID) AS TOTAL,
  SUM(CASE WHEN true=1 THEN 1 ELSE 0 END) AS 'TRUE'
FROM
  (SELECT DISTINCT uID,questionID,true  FROM question_history)t
GROUP BY
  UID


DROP TABLE question_history

/*UID         TOTAL       TRUE
----------- ----------- -----------
123         2           2
456         2           2

(2 行受影响)*/