Error 1452: Unable to add or update child row: foreign key constraint failed

Question

我在 MySQL Workbench 中创建了表，如下所示：

ORDRE 表：

CREATE TABLE Ordre (
  OrdreID   INT NOT NULL,
  OrdreDato DATE DEFAULT NULL,
  KundeID   INT  DEFAULT NULL,
  CONSTRAINT Ordre_pk PRIMARY KEY (OrdreID),
  CONSTRAINT Ordre_fk FOREIGN KEY (KundeID) REFERENCES Kunde (KundeID)
)
  ENGINE = InnoDB;

产品表：

CREATE TABLE Produkt (
  ProduktID          INT NOT NULL,
  ProduktBeskrivelse VARCHAR(100) DEFAULT NULL,
  ProduktFarge       VARCHAR(20)  DEFAULT NULL,
  Enhetpris          INT          DEFAULT NULL,
  CONSTRAINT Produkt_pk PRIMARY KEY (ProduktID)
)
  ENGINE = InnoDB;

和ORDRELINJE表：

CREATE TABLE Ordrelinje (
  Ordre         INT NOT NULL,
  Produkt       INT NOT NULL,
  AntallBestilt INT DEFAULT NULL,
  CONSTRAINT Ordrelinje_pk PRIMARY KEY (Ordre, Produkt),
  CONSTRAINT Ordrelinje_fk FOREIGN KEY (Ordre) REFERENCES Ordre (OrdreID),
  CONSTRAINT Ordrelinje_fk1 FOREIGN KEY (Produkt) REFERENCES Produkt (ProduktID)
)
  ENGINE = InnoDB;

因此，当我尝试将值插入 ORDRELINJE 表时，我得到：

错误代码：1452。无法添加或更新子行：外键约束失败（srdjank.Ordrelinje，CONSTRAINT Ordrelinje_fk FOREIGN关键（Ordre）参考Ordre（OrdreID））

我看过有关此主题的其他帖子，但没有运气。 我是否在监督某些事情或知道要做什么？

Answer 1

Taken fromUsing foreign key constraints

Thus, your error Error code: 1452. Unable to add or update child row: Foreign key constraint failure Essentially means, you are trying to add a row to OrdrelinjeOrdre The code> for the matching row (OrderID) does not exist in the table surface.

You must first insert the row into the Ordre table.