SQLite View 利用忽略数据值的计算

Question

大家下午好，

利用下面的代码，我创建了一个视图，用于计算每英里的平均时间。

CREATE VIEW AverageRunTime AS
SELECT UserDetails.username AS username,
CardiovascularRecords.distance_in_miles AS distance,
CardiovascularRecords.start_time AS starttime,
CardiovascularRecords.end_time AS endtime,
sum(strftime('%s', end_time) - strftime('%s', start_time) / distance_in_miles) AS averagespeedpermile
FROM UserDetails INNER JOIN CardiovascularRecords
ON Userdetails.username=CardiovascularRecords.username

我遇到的问题是考虑到距离变量，使用 REAL 数据类型时，我有几个十进制值，例如从 0.1 到 1 的范围。

执行上述求和时，视图将仅显示与整数相关的数据，而完全忽略任何包含十进制值的记录。

非常欢迎对此问题提供任何帮助，与我的架构相关的代码也包含在下面，以允许其他人复制我的工作。

CREATE TABLE "CardiovascularRecords" ("record_ID" INTEGER PRIMARY KEY  AUTOINCREMENT  NOT NULL  UNIQUE CHECK (record_ID>0) , "distance_in_miles" REAL NOT NULL CHECK (distance_in_miles>0) , "username" TEXT NOT NULL , "date" DATETIME DEFAULT CURRENT_DATE, "notes" TEXT(50), "start_time" TEXT, "end_time" TEXT, FOREIGN KEY(distance_in_miles) REFERENCES DistanceinMiles(distance_in_miles) ON DELETE CASCADE ON UPDATE CASCADE,FOREIGN KEY(username) REFERENCES UserDetails(username) ON DELETE CASCADE ON UPDATE CASCADE)

CREATE TABLE "UserDetails" ("username" TEXT PRIMARY KEY  NOT NULL  UNIQUE  CHECK (length(username)>0), "password" TEXT NOT NULL  CHECK (length(password)>3), "email_address" TEXT NOT NULL  UNIQUE CHECK (length(email_address)>3) , "weight_in_pounds" REAL NOT NULL CHECK(weight_in_pounds>0) CHECK (length(weight_in_pounds)>0), "height_in_inches" REAL NOT NULL CHECK(height_in_inches>0) CHECK (length(height_in_inches)>0), "age" INTEGER CHECK(age>0), WITHOUT ROWID)

提前谢谢你。

Answer 1

SQLite 使用dynamic typing，因此可以将字符串插入distance_in_miles 列。

检查distance_in_miles>0 没有帮助，因为any string compares larger than any number。

修复您的程序以将值存储为数字。