为什么我不断收到错误代码 1146 in MySQL 之类的错误？

Question

我一直收到 1146 错误代码：1146。Table 'world.itemsintransactions' 不存在，在我继续收到许多其他不同的错误代码之前，我最终修复只是为了转移到另一个错误代码。请记住这是我的第一个 MySQL 作业，在此作业之前从未使用过 MySQL，所以如果我错过了一些非常明显的东西，我们深表歉意！

这是我的代码...

Create DATABASE CS_Store;
USE CS_Store;

CREATE TABLE customers (
    birth_day date,
    first_name VARCHAR(20),
    last_name VARCHAR(20),
    c_id VARCHAR(20),
    CONSTRAINT PK_Customers PRIMARY KEY (c_id));
INSERT INTO customers (birth_day, first_name, last_name, c_id) VALUES ('1993-07-11','Victor','Davis',1);
INSERT INTO customers (birth_day, first_name, last_name, c_id) VALUES ('2001-03-28','Katarina','Williams',2);
INSERT INTO customers (birth_day, first_name, last_name, c_id) VALUES ('1965-12-11','David','Jones',3);
INSERT INTO customers (birth_day, first_name, last_name, c_id) VALUES ('1980-10-10','Evelyn','Lee',4);


CREATE TABLE employees (
    birth_day date,
    first_name VARCHAR(20),
    last_name VARCHAR(20),
    e_id int,
    CONSTRAINT PK_Employees PRIMARY KEY (e_id)
);
INSERT INTO employees (birth_day, first_name, last_name, e_id) VALUES ('1983-09-02','David','Smith',1);
INSERT INTO employees (birth_day, first_name, last_name, e_id) VALUES ('1990-07-23','Olivia','Brown',2);
INSERT INTO employees (birth_day, first_name, last_name, e_id) VALUES ('1973-05-11','David','Johnson',3);
INSERT INTO employees (birth_day, first_name, last_name, e_id) VALUES ('1999-11-21','Mia','Taylor',4);

CREATE TABLE transactions (
    e_id int,
    c_id int,
    date date,
    t_id int,
    CONSTRAINT PK_transactions PRIMARY KEY (t_id),
    FOREIGN KEY (e_id) REFERENCES employees(e_id),
    FOREIGN KEY (c_id) REFERENCES customers(c_id)
);
INSERT INTO transactions (e_id, c_id, date, t_id) VALUES (1,1,'2020-8-11',1);
INSERT INTO transactions (e_id, c_id, date, t_id) VALUES (3,1,'2020-8-15',2);
INSERT INTO transactions (e_id, c_id, date, t_id) VALUES (1,4,'2020-9-01',3);
INSERT INTO transactions (e_id, c_id, date, t_id) VALUES (2,2,'2020-9-07',4);
INSERT INTO transactions (e_id, c_id, date, t_id) VALUES (4,3,'2020-9-07',5);


CREATE TABLE items (
    amount int,
    price_for_each int,
    name VARCHAR(20),
    CONSTRAINT PK_items PRIMARY KEY (name)
);
INSERT INTO items (price_for_each, amount, name) VALUES (110,22,'2lof milk');
INSERT INTO items (price_for_each, amount, name) VALUES (99,30,'6 cans of lemonade');
INSERT INTO items (price_for_each, amount, name) VALUES (150,20,'Pack of butter');
INSERT INTO items (price_for_each, amount, name) VALUES (450,13,'Roast chicken');
INSERT INTO items (price_for_each, amount, name) VALUES (99,30,'Pack of rice');
INSERT INTO items (price_for_each, amount, name) VALUES (20,50,'Banana');
INSERT INTO items (price_for_each, amount, name) VALUES (200,30,'3kg sugar');
INSERT INTO items (price_for_each, amount, name) VALUES (150,15,'Toast bread');
INSERT INTO items (price_for_each, amount, name) VALUES (150,18,'Earl Grey tea');

CREATE TABLE promotions (
    discount int,
    p_id int,
    CONSTRAINT PK_promotions PRIMARY KEY (p_id)
);
INSERT INTO promotions (discount, p_id) VALUES (99,1);
INSERT INTO promotions (discount, p_id) VALUES (200,2);
INSERT INTO promotions (discount, p_id) VALUES (150,3);
INSERT INTO promotions (discount, p_id) VALUES (150,4);

CREATE TABLE itemsinpromotions (
    name VARCHAR(20),
    p_id int,
    amount int,
    FOREIGN KEY (name) REFERENCES items(name),
    FOREIGN KEY (p_id) REFERENCES promotions(p_id)
);
INSERT INTO itemsinpromotions (name, p_id, amount) VALUES ('6 cans of lemonade',1,2);
INSERT INTO itemsinpromotions (name, p_id, amount) VALUES ('Roast chicken',2,1);
INSERT INTO itemsinpromotions (name, p_id, amount) VALUES ('Pack of rice',2,1);
INSERT INTO itemsinpromotions (name, p_id, amount) VALUES ('Pack of butter',3,1);
INSERT INTO itemsinpromotions (name, p_id, amount) VALUES ('Toast bread',3,2);
INSERT INTO itemsinpromotions (name, p_id, amount) VALUES ('2lof milk',4,2);
INSERT INTO itemsinpromotions (name, p_id, amount) VALUES ('Banana',4,3);
INSERT INTO itemsinpromotions (name, p_id, amount) VALUES ('3kg sugar',4,2);

CREATE TABLE itemsintransactions (
    name VARCHAR(20),
    t_id int,
    amount int,
    FOREIGN KEY (name) REFERENCES items(name),
    FOREIGN KEY (t_id) REFERENCES transactions(t_id)
);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES('6 cans of lemonade',1,1);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Roast chicken',1,1);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Pack of butter',1,1);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Toast bread',1,1);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('2lof milk',1,2);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Banana',1,3);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('3kg sugar',1,1);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('6 cans of lemonade',2,5);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Pack of rice',2,1);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('6 cans of lemonade',3,3);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Roast chicken',3,2);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Pack of rice',3,1);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Pack of butter',3,1);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('2lof milk',4,5);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Banana',4,20);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('3kg sugar',4,8);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('6 cans of lemonade',5,10);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Roast chicken',5,10);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Pack of rice',5,10);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Pack of butter',5,10);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Toast bread',5,10);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('2lof milk',5,10);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Banana',5,10);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('3kg sugar',5,10);
INSERT INTO itemsintransactions (name, t_id, amount) VALUES ('Earl Grey tea',5,10);



CREATE VIEW DavidSoldTo AS 
    SELECT birth_day, first_name, last_name
    FROM customers
    WHERE EXISTS (SELECT 1 FROM Transactions WHERE e_id=1)
    ORDER BY birth_day
;

CREATE VIEW PeopleInShop AS 
    SELECT DISTINCT birth_day, first_name, last_name
    FROM Employees
    UNION
    SELECT DISTINCT birth_day, first_name, last_name
    FROM Customers
    WHERE EXISTS (SELECT 1 FROM Transactions WHERE date=2020-9-07)
    ORDER BY birth_day
;


CREATE VIEW ItemsLeft AS 
    SELECT amount AS amount_left, name
    FROM Items
    WHERE amount_left NOT IN (SELECT COUNT(t_id) FROM Transactions)
    GROUP BY name
;
    
    
    -- Not yet completed
CREATE VIEW PromotionItemsSatisfiedByTransactions AS
    SELECT name, p_id, COUNT(t_id) AS number_of_times
    FROM Promotions NATURAL JOIN Transactions
    SELECT number_of_times 
    WHERE number_of_times >= 1;c_id

Answer 1

一个mysql数据库服务器可以有多个数据库，如CS_Store。当访问当前 USE 以外的数据库时，您使用数据库名称限定 table 名称。 world.itemsintransactions 是对 world 数据库中 itemsintransactions table 的引用，您似乎并未实际创建它。也许您的说明打算让您使用 world 而不是 CS_Store?

Answer 2

除了@ysth 解释的与架构名称相关的错误之外，您的代码还有另一个问题。考虑这些 table 声明：

create table customers (
    birth_day date,
    first_name varchar(20),
    last_name varchar(20),
    c_id varchar(20),
    constraint pk_customers primary key (c_id)
);

create table transactions (
    e_id int,
    c_id int,
    date date,
    t_id int,
    constraint pk_transactions primary key (t_id),
    foreign key (e_id) references employees(e_id),
    foreign key (c_id) references customers(c_id)
);

问题是 customers(c_id) 的数据类型是 varchar(20)，而引用列 transactions(c_id) 是 int。因此，外键约束创建失败，table transactions 的创建也是如此。缺少的 table 会在脚本的其余部分传播错误。

修复其中一种数据类型，使它们完全相同。我希望称为 ..._id 的东西是 int。然后，整个脚本应该就可以正常工作了。

Demo on DB Fiddle

为什么我不断收到错误代码 1146 in MySQL 之类的错误？

Why do I keep on getting errors like Error Code 1146 in MySQL?

mysql

sql

foreign-keys

create-table

sql-insert