SQLite3 UNIQUE 约束失败错误

Question

我正在尝试创建一个数据库，允许用户创建“待办事项”列表并在其中填写要完成的项目。但是，当向表中插入数据时，它给了我一个 UNIQUE 约束失败错误，我不知道如何解决它。这是我创建数据库和插入数据的代码。

CREATE TABLE user (
    user_id integer  NOT NULL   PRIMARY KEY,
    first_name varchar(15)  NOT NULL,
    title varchar(5)  NOT NULL,
    username varchar(15)  NOT NULL,
    password varchar(20)  NOT NULL,
    email varchar(50)  NOT NULL,
    bio text  NOT NULL
);


CREATE TABLE list (
    list_id integer  NOT NULL   PRIMARY KEY,
    list_name varchar(10)  NOT NULL,
    user_user_id integer  NOT NULL,
    FOREIGN KEY (user_user_id) REFERENCES user(user_id)
);


CREATE TABLE item (
    item_id integer  NOT NULL   PRIMARY KEY,
    item text  NOT NULL,
    completed boolean  NOT NULL,
    list_list_id integer  NOT NULL,
    FOREIGN KEY (list_list_id) REFERENCES list(list_id)
);


-- Data:
INSERT INTO user VALUES (1, "Name1", "Title1", "Username1", "Password1", "Email1", "Bio1");
INSERT INTO user VALUES (2, "Name2", "Title2", "Username2", "Password2", "Email2", "Bio2");
INSERT INTO user VALUES (3, "Name3", "Title3", "Username3", "Password3", "Email3", "Bio3");

INSERT INTO list VALUES (1, "user1-list1", 1);
INSERT INTO list VALUES (2, "user1-list2", 1);
INSERT INTO list VALUES (3, "user1-list3", 1);
INSERT INTO list VALUES (1, "user2-list1", 2);
INSERT INTO list VALUES (1, "user3-list1", 3);
INSERT INTO list VALUES (2, "user3-list2", 3);

INSERT INTO item VALUES (1, "user1-list1-item1", "FALSE", 1);
INSERT INTO item VALUES (2, "user1-list1-item2", "FALSE", 1);
INSERT INTO item VALUES (1, "user1-list2-item1", "FALSE", 2);
INSERT INTO item VALUES (1, "user1-list3-item1", "FALSE", 3);
INSERT INTO item VALUES (2, "user1-list3-item2", "FALSE", 3);
INSERT INTO item VALUES (1, "user2-list1-item1", "FALSE", 1);
INSERT INTO item VALUES (2, "user2-list1-item1", "FALSE", 1);
INSERT INTO item VALUES (1, "user3-list1-item1", "FALSE", 1);
INSERT INTO item VALUES (1, "user3-list3-item1", "FALSE", 2);

我已复制以下收到的错误：

Error: near line 43: UNIQUE constraint failed: list.list_id
Error: near line 44: UNIQUE constraint failed: list.list_id
Error: near line 45: UNIQUE constraint failed: list.list_id
Error: near line 49: UNIQUE constraint failed: item.item_id
Error: near line 50: UNIQUE constraint failed: item.item_id
Error: near line 51: UNIQUE constraint failed: item.item_id
Error: near line 52: UNIQUE constraint failed: item.item_id
Error: near line 53: UNIQUE constraint failed: item.item_id
Error: near line 54: UNIQUE constraint failed: item.item_id
Error: near line 55: UNIQUE constraint failed: item.item_id

任何帮助将不胜感激！

Answer 1

当您插入的数据有一个条目已经在您要插入的表的相应列中时，您会收到UNIQUE constraint failed 错误。

如果您希望 SQL 忽略该错误并继续添加其他记录，请执行以下操作：

---

INSERT or IGNORE into tablename VALUES (value1,value2 , so on );

---

如果您想在条目已经存在时替换表中的值，请执行以下操作：

---

INSERT or REPLACE into tablename VALUES (value1,value2 , so on );

这可以节省您的大量处理时间并且非常有用。

Answer 2

您已将 list_id 设置为列表表的主键，这意味着每个记录的值必须是唯一的。因此，尝试使用相同的 list_id 表插入多条记录会导致错误。

item 表的问题是一样的。