两个表是什么导致了这种行为？

-- 创建用户表
CREATE TABLE Users (
    UserID INT PRIMARY KEY,
    UserName VARCHAR(255) NOT NULL
);

-- 创建用户详情表
CREATE TABLE UserDetails (
    DetailID INT PRIMARY KEY,
    UserID INT,
    Address VARCHAR(255),
    FOREIGN KEY (UserID) REFERENCES Users(UserID)
);

-- 创建订单表
CREATE TABLE Orders (
    OrderID INT PRIMARY KEY,
    UserID INT,
    OrderDate DATE,
    FOREIGN KEY (UserID) REFERENCES Users(UserID)
);

-- 创建订单项表
CREATE TABLE OrderItems (
    ItemID INT PRIMARY KEY,
    OrderID INT,
    ProductID INT,
    Quantity INT,
    FOREIGN KEY (OrderID) REFERENCES Orders(OrderID)
);

-- 创建产品表
CREATE TABLE Products (
    ProductID INT PRIMARY KEY,
    ProductName VARCHAR(255),
    Price DECIMAL(10, 2)
);