如何使用引用復合主鍵的復合外鍵將行插入到表中

Question

我有一張名為 BB 的表：

CREATE TABLE BB (
    SID INTEGER PRIMARY KEY,
    FName TEXT,
    LName TEXT
);

還有一個名為 QR 的表，其中包含一個復合外鍵，引用 BB 表上的 FName 和 LName 行。

CREATE TABLE QR (
    QID INTEGER PRIMARY KEY AUTOINCREMENT,
    FName TEXT,
    LName TEXT,
    DateTime_IN TEXT,
    Sid4 INTEGER,
    Mode TEXT,
    FOREIGN KEY (FName, LName) REFERENCES BB (FName, LName)
);

並且 BB 表中填充了以下數據：

INSERT INTO BB (SID, FName, LName) VALUES
(12345678, "R", "B"),
(23456789, "X", "C"),
(34567890, "M", "S"),
(45678901, "Z", "H"),
(56789012, "T", "A"),
(67890123, "N", "F"),
(78901234, "H", "M"),
(89012345, "A", "S"),
(90123456, "F", "F"),
(12345677, "M", "M");

並且需要將此數據插入到 QR 表中：

INSERT INTO QR
(FName, LName, DateTime_IN, Sid4, Mode)
VALUES
("R", "B", "2021-08-10 14:00:02", 12345678, "ZOOM"),
("X", "C", "2021-08-10 14:00:02", 23456789, "ZOOM"),
("M", "S", "2021-08-10 14:00:03", 34567890, "ZOOM"),
("Z", "H", "2021-08-10 15:01:01", 45678901, "ZOOM"),
("T", "A", "2021-08-10 14:01:01", 56789012, "ZOOM"),
("N", "F", "2021-08-10 14:02:02", 67890123, "ZOOM"),
("H", "M", "2021-08-10 14:03:03", 78901234, "ZOOM"),
("A", "S", "2021-08-11 14:04:04", 89012345, "ZOOM");

但是當我在數據庫瀏覽器中運行它時，我得到了這個錯誤：

Execution finished with errors.
Result: foreign key mismatch - "QR" referencing "BB"
At line 1:
INSERT INTO QR
(FName, LName, DateTime_IN, Sid4, Mode)
VALUES
("R", "B", "2021-08-10 14:00:02", 12345678, "ZOOM"),
("X", "C", "2021-08-10 14:00:02", 23456789, "ZOOM"),
("M", "S", "2021-08-10 14:00:03", 34567890, "ZOOM"),
("Z", "H", "2021-08-10 15:01:01", 45678901, "ZOOM"),
("T", "A", "2021-08-10 14:01:01", 56789012, "ZOOM"),
("N", "F", "2021-08-10 14:02:02", 67890123, "ZOOM"),
("H", "M", "2021-08-10 14:03:03", 78901234, "ZOOM"),
("A", "S", "2021-08-11 14:04:04", 89012345, "ZOOM");

為什么它不讓我插入這些數據。 所有數據均正確且與 BB 表匹配。 我正在使用帶有 DB Browser 的 SQLite 版本 3.34.1

Answer 1

您的代碼的問題是父表BB的FName和LName的組合未定義為UNIQUE 。
通過此更改：

CREATE TABLE BB (
    SID INTEGER PRIMARY KEY,
    FName TEXT,
    LName TEXT, 
    UNIQUE(FName, LName)
);

它會正常工作。

但是，在您的情況下，正確的設計是在QR中定義一個引用BB列SID而不是復合外鍵的整數列：

CREATE TABLE QR (
    QID INTEGER PRIMARY KEY AUTOINCREMENT,
    SID INTEGER REFERENCES BB (SID),
    DateTime_IN TEXT,
    Sid4 INTEGER,
    Mode TEXT
);