mysql-如何使用typeorm中具有自动增量id列的表进行级联插入

我正在尝试使用typeorm实现级联插入.子表条目包括对父表ID字段的外键引用.

看来typeorm并未从父行中捕获自动增量id并将其提供给子插入.

这是父实体：

import ...
@Entity("parent")
export class Parent {
    @PrimaryGeneratedColumn()
    id: number;

    @OneToOne(type => Account, accountId => accountId.provider)
    @JoinColumn({name: "account_id"})
    accountId: Account;

    @Column("varchar", {
        name: "name",
        nullable: false,
        length: 255,
    })
    name: string;

    @OneToMany(type => Child, Children => Children.parentId, {
        cascadeInsert: true,
        cascadeUpdate: true
    })
    Children: Child[];

}

子实体：

import ...

@Entity("child")
export class Child{
    @PrimaryGeneratedColumn()
    id: number;

    @ManyToOne(type => Parent, parentId => parentId.children)
    @JoinColumn({name: "parent_id"})
    parentId: Parent;

    @Column("varchar", {
        name: "number",
        nullable: true,
        length: 45,
    })
    number: string;

}

控制台日志显示所生成的sql不包含外键列,从而产生明显的错误ER_NO_DEFAULT_FOR_FIELD：字段“ parent_id”没有默认值

info: executing query:  START TRANSACTION
info: executing query:  INSERT INTO parent(name, account_id) VALUES (?,?) -- PARAMETERS: ["Name","id"]
info: executing query:  INSERT INTO child(number) VALUES (?) -- PARAMETERS: ["12345678"]
info: query failed:  INSERT INTO child(number) VALUES (?) -- PARAMETERS: ["12345678"]
info: error:  { Error: ER_NO_DEFAULT_FOR_FIELD: Field 'parent_id' doesn't have a default value

是否可以通过某种方式指示typeorm捕获LAST_INSERT_ID()或以其他方式填充子行上的foregin键id字段？

解决方法:

如果ID不是自动生成的,而是在保存实体之前分配的,则该ID有效.

使用uuid作为主键.

import ...
@Entity("parent")
export class Parent {

    @PrimaryColumn()
    id: string;

    @OneToOne(type => Account, accountId => accountId.provider)
    @JoinColumn({name: "account_id"})
    accountId: Account;

    @Column("varchar", {
        name: "name",
        nullable: false,
        length: 255,
    })
    name: string;

    @OneToMany(type => Child, Children => Children.parentId, {
        cascadeInsert: true,
        cascadeUpdate: true
   })
   Children: Child[];
}

和创建实体时.

const parent: Parent = new Parent();
parent.id = "896b677f-fb14-11e0-b14d-d11ca798dbac"; // your uuid goes here

不幸的是,您也不能使用@PrimaryGeneratedColumn(“ uuid”).

有很多库可以在JS中生成uuid.

uuid-js的示例-https://github.com/pnegri/uuid-js

const parent: Parent = new Parent();
parent.id = UUID.create(4).toString();

我认为这更像是一种解决方法,而不是问题的解决方案.但是我找不到一种让TypeORM在级联孩子时考虑生成的ID的方法.

标签：node-js,typeorm,mysql
来源： https://codeday.me/bug/20191110/2013397.html