Mysql 计算有利百分比

我有一个调查答复表，范围包括以下选择。 强烈同意=5，同意=4，中立=3，不同意=2，强烈不同意=1

该表看起来有点像这样：

ID:  Q1  Q2  Q3  Q4  Qn
1    5   4   5   3   2
2    4   5   2   1   4
3    4   4   3   2   3
4    5   4   3   4   3

我使用下面的MySQL代码获取一个列，并为百分比有利、中性和不利生成3个附加列

Select 
(case when Q1 = 5 or Q1 = 4 then 1 else null end) as Q1Fav,
(case when Q1 = 3 then 1 else null end) as Q1Neu,
(case when Q1 = 2 or Q1 = 1 then 1 else null end) as Q1UnFav
From survey_data

这给了我一列中Q1的有利响应，另一列中的中性响应，等等

有没有办法扩展它，让MySQL继续生成这些列，直到它到达Qn？（其中Qn是调查的最后一个问题，也是我列表中的最后一列）

提前感谢您的帮助

——这应该是您所需要的全部

--你可以进行900万次调查

--一个可以有200个问题，另一个可以有4个。不管怎样

create table users
(
    userId int auto_increment primary key,
    fName varchar(100) not null,    -- Stan 
    lName varchar(100) not null     -- Smith
)ENGINE=MyIsam;

create table surveys
(
    surveyId int auto_increment primary key,
    sTitle varchar(255) not null,
    dtCreated date not null -- date created in system
)ENGINE=MyIsam;

-- create table questions
-- (    -- to keep things simple to start, assume questions are not in mysql
    -- that can be for version Beta 0.02
-- );

create table UserTakesSurvey
(   -- A user takes a survey (this is going to be useful)
    -- 1 row for each combo kinda obvious
    userId int not null,
    surveyId int not null,
    dtTaken date not null,

    -- Foreign Key constraints go here:
    -- to Users Table:
    FOREIGN KEY (userId) REFERENCES users(userId),
    -- to Surveys Table:
    FOREIGN KEY (surveyId) REFERENCES surveys(surveyId),
    -- so no row can exist here with a wrong (non-existing) userId or surveyId

    -- addition indexes here:
    primary key (userid,surveyid),
    key (surveyid,userid)
)ENGINE=MyIsam;

create table answers
(   id int auto_increment primary key,
    userId int not null,
    surveyId int not null, -- survey id
    qNum int not null,  -- question number
    answer int not null,    -- 5 to 1

    -- Foreign Key constraints go here:
    -- to Users Table:
    FOREIGN KEY (userId) REFERENCES users(userId),
    -- to Surveys Table:
    FOREIGN KEY (surveyId) REFERENCES surveys(surveyId),
    -- so no row can exist here with a wrong (non-existing) userId or surveyId

    -- Additional indexes go here:
    -- create a composite (combo) key incorporating two columns
    KEY (userId,surveyId),
    KEY (surveyId,userId)
)ENGINE=MyIsam;

insert users (fName,lName) values ('Stan','Smith'),('Sally','Higgins');

-- first survey will have 7 questions hypothetically, 2nd 101 questions
insert surveys (sTitle,dtCreated) values ('Feelings about Milk','2013-01-17');
insert surveys (sTitle,dtCreated) values ('Thoughts on Global Warming',curdate());

--这应该是你所需要的

--你可以进行900万次调查

--一个可以有200个问题，另一个可以有4个。不管怎样

create table users
(
    userId int auto_increment primary key,
    fName varchar(100) not null,    -- Stan 
    lName varchar(100) not null     -- Smith
)ENGINE=MyIsam;

create table surveys
(
    surveyId int auto_increment primary key,
    sTitle varchar(255) not null,
    dtCreated date not null -- date created in system
)ENGINE=MyIsam;

-- create table questions
-- (    -- to keep things simple to start, assume questions are not in mysql
    -- that can be for version Beta 0.02
-- );

create table UserTakesSurvey
(   -- A user takes a survey (this is going to be useful)
    -- 1 row for each combo kinda obvious
    userId int not null,
    surveyId int not null,
    dtTaken date not null,

    -- Foreign Key constraints go here:
    -- to Users Table:
    FOREIGN KEY (userId) REFERENCES users(userId),
    -- to Surveys Table:
    FOREIGN KEY (surveyId) REFERENCES surveys(surveyId),
    -- so no row can exist here with a wrong (non-existing) userId or surveyId

    -- addition indexes here:
    primary key (userid,surveyid),
    key (surveyid,userid)
)ENGINE=MyIsam;

create table answers
(   id int auto_increment primary key,
    userId int not null,
    surveyId int not null, -- survey id
    qNum int not null,  -- question number
    answer int not null,    -- 5 to 1

    -- Foreign Key constraints go here:
    -- to Users Table:
    FOREIGN KEY (userId) REFERENCES users(userId),
    -- to Surveys Table:
    FOREIGN KEY (surveyId) REFERENCES surveys(surveyId),
    -- so no row can exist here with a wrong (non-existing) userId or surveyId

    -- Additional indexes go here:
    -- create a composite (combo) key incorporating two columns
    KEY (userId,surveyId),
    KEY (surveyId,userId)
)ENGINE=MyIsam;

insert users (fName,lName) values ('Stan','Smith'),('Sally','Higgins');

-- first survey will have 7 questions hypothetically, 2nd 101 questions
insert surveys (sTitle,dtCreated) values ('Feelings about Milk','2013-01-17');
insert surveys (sTitle,dtCreated) values ('Thoughts on Global Warming',curdate());

---

德鲁，非常感谢你的帮助。我听不懂你的回答。我是MySQL的新手，非常感谢您的帮助。没问题，让我添加更多内容需要15分钟谢谢。如果有帮助的话，如果不清楚的话，我正在处理的表格中的每一条记录都代表一个调查对象，列代表调查问题本身。我知道。我正在介绍我认为更聪明的设计，并将解释原因。你可以把它放在架子上思考一下，如果这些答案有帮助，然后向上投票，如果很糟糕，然后向下投票，绿色复选标记回答，所以它对你（和其他人都知道）关闭Drew，非常感谢你的帮助。我听不懂你的回答。我是MySQL的新手，非常感谢您的帮助。没问题，让我添加更多内容需要15分钟谢谢。如果有帮助的话，如果不清楚的话，我正在处理的表格中的每一条记录都代表一个调查对象，列代表调查问题本身。我知道。我正在介绍我认为更聪明的设计，并将解释原因。你可以把它放在一个架子上，思考一下这些答案是否有用，然后向上投票，如果很糟糕，然后向下投票，绿色复选标记回答，这样它就对你关闭了（其他人也知道）