Swift 5.2 Xcode 11.4 Vapor 4.0.0我应该如何在我的模型中编码PK？

我的

Package.swift

文件如下所示：

.package(url: "https://github.com/vapor/vapor.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent-postgres-driver.git", from: "2.0.0-rc")

app.databases.use(.postgres(
    hostname: Environment.get("DATABASE_HOST") ?? "localhost",
    username: Environment.get("DATABASE_USERNAME") ?? "postgres",
    password: Environment.get("DATABASE_PASSWORD") ?? "secret",
    database: Environment.get("DATABASE_NAME") ?? "mydb2"
), as: .psql)

import Fluent
import Vapor


final class Complaint: Model, Content {

    static let schema = "cw_complaint5"

    @ID(key: .id)
    var id: UUID?

    @Field(key: "issue_description")
    var issue_description: String

    // etc.
    init() { }
}

mydb2=# \d+ cw_complaint5
                                              Table "public.cw_complaint5"
        Column        |          Type           | Collation | Nullable | Default | Storage  | Stats target | Description 
----------------------+-------------------------+-----------+----------+---------+----------+--------------+-------------
 id                   | integer                 |           | not null |         | plain    |              | 
 row                  | smallint                |           |          |         | plain    |              | 
 document_number      | integer                 |           | not null |         | plain    |              |
...etc...
county_id            | integer                 |           |          |         | plain    |              | 
 city_id              | integer                 |           |          |         | plain    |              | 
 operator_id          | integer                 |           |          |         | plain    |              | 
Indexes:
    "cw_complaint5_pkey" PRIMARY KEY, btree (id)
Check constraints:
    "cw_complaint5_row_check" CHECK ("row" >= 0)
Foreign-key constraints:
    "cw_complaint5_city_id_fkey" FOREIGN KEY (city_id) REFERENCES cw_city5(id)
    "cw_complaint5_county_id_fkey" FOREIGN KEY (county_id) REFERENCES cw_county5(id)
    "cw_complaint5_operator_id_fkey" FOREIGN KEY (operator_id) REFERENCES cw_operator5(id)

(END)

{"id":729,"issue_description":"test","document_number":99,"api_state_code":88,"api_county_code":11,"section":22,"city_id":51,"county_id":56,"operator_id":4415}

我的

config.swift

文件如下所示：

.package(url: "https://github.com/vapor/vapor.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent-postgres-driver.git", from: "2.0.0-rc")

app.databases.use(.postgres(
    hostname: Environment.get("DATABASE_HOST") ?? "localhost",
    username: Environment.get("DATABASE_USERNAME") ?? "postgres",
    password: Environment.get("DATABASE_PASSWORD") ?? "secret",
    database: Environment.get("DATABASE_NAME") ?? "mydb2"
), as: .psql)

import Fluent
import Vapor


final class Complaint: Model, Content {

    static let schema = "cw_complaint5"

    @ID(key: .id)
    var id: UUID?

    @Field(key: "issue_description")
    var issue_description: String

    // etc.
    init() { }
}

mydb2=# \d+ cw_complaint5
                                              Table "public.cw_complaint5"
        Column        |          Type           | Collation | Nullable | Default | Storage  | Stats target | Description 
----------------------+-------------------------+-----------+----------+---------+----------+--------------+-------------
 id                   | integer                 |           | not null |         | plain    |              | 
 row                  | smallint                |           |          |         | plain    |              | 
 document_number      | integer                 |           | not null |         | plain    |              |
...etc...
county_id            | integer                 |           |          |         | plain    |              | 
 city_id              | integer                 |           |          |         | plain    |              | 
 operator_id          | integer                 |           |          |         | plain    |              | 
Indexes:
    "cw_complaint5_pkey" PRIMARY KEY, btree (id)
Check constraints:
    "cw_complaint5_row_check" CHECK ("row" >= 0)
Foreign-key constraints:
    "cw_complaint5_city_id_fkey" FOREIGN KEY (city_id) REFERENCES cw_city5(id)
    "cw_complaint5_county_id_fkey" FOREIGN KEY (county_id) REFERENCES cw_county5(id)
    "cw_complaint5_operator_id_fkey" FOREIGN KEY (operator_id) REFERENCES cw_operator5(id)

(END)

{"id":729,"issue_description":"test","document_number":99,"api_state_code":88,"api_county_code":11,"section":22,"city_id":51,"county_id":56,"operator_id":4415}

我的模型看起来像：

.package(url: "https://github.com/vapor/vapor.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent-postgres-driver.git", from: "2.0.0-rc")

app.databases.use(.postgres(
    hostname: Environment.get("DATABASE_HOST") ?? "localhost",
    username: Environment.get("DATABASE_USERNAME") ?? "postgres",
    password: Environment.get("DATABASE_PASSWORD") ?? "secret",
    database: Environment.get("DATABASE_NAME") ?? "mydb2"
), as: .psql)

import Fluent
import Vapor


final class Complaint: Model, Content {

    static let schema = "cw_complaint5"

    @ID(key: .id)
    var id: UUID?

    @Field(key: "issue_description")
    var issue_description: String

    // etc.
    init() { }
}

mydb2=# \d+ cw_complaint5
                                              Table "public.cw_complaint5"
        Column        |          Type           | Collation | Nullable | Default | Storage  | Stats target | Description 
----------------------+-------------------------+-----------+----------+---------+----------+--------------+-------------
 id                   | integer                 |           | not null |         | plain    |              | 
 row                  | smallint                |           |          |         | plain    |              | 
 document_number      | integer                 |           | not null |         | plain    |              |
...etc...
county_id            | integer                 |           |          |         | plain    |              | 
 city_id              | integer                 |           |          |         | plain    |              | 
 operator_id          | integer                 |           |          |         | plain    |              | 
Indexes:
    "cw_complaint5_pkey" PRIMARY KEY, btree (id)
Check constraints:
    "cw_complaint5_row_check" CHECK ("row" >= 0)
Foreign-key constraints:
    "cw_complaint5_city_id_fkey" FOREIGN KEY (city_id) REFERENCES cw_city5(id)
    "cw_complaint5_county_id_fkey" FOREIGN KEY (county_id) REFERENCES cw_county5(id)
    "cw_complaint5_operator_id_fkey" FOREIGN KEY (operator_id) REFERENCES cw_operator5(id)

(END)

{"id":729,"issue_description":"test","document_number":99,"api_state_code":88,"api_county_code":11,"section":22,"city_id":51,"county_id":56,"operator_id":4415}

在Xcode中，项目构建正常，此

GET

路由运行正常：

http://localhost:8080/complaint

但是当我运行

POST

路由时，我在响应正文中得到一个错误：

{
    "error": true,
    "reason": "Value of type 'UUID' required for key 'id'."
}

在Vapor 3中，

POST

路由在插入新行（在JSON请求正文中省略ID）和更新现有行方面都工作得很好。PostgreSQL 11.3上的表说明如下所示：

.package(url: "https://github.com/vapor/vapor.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent-postgres-driver.git", from: "2.0.0-rc")

app.databases.use(.postgres(
    hostname: Environment.get("DATABASE_HOST") ?? "localhost",
    username: Environment.get("DATABASE_USERNAME") ?? "postgres",
    password: Environment.get("DATABASE_PASSWORD") ?? "secret",
    database: Environment.get("DATABASE_NAME") ?? "mydb2"
), as: .psql)

import Fluent
import Vapor


final class Complaint: Model, Content {

    static let schema = "cw_complaint5"

    @ID(key: .id)
    var id: UUID?

    @Field(key: "issue_description")
    var issue_description: String

    // etc.
    init() { }
}

mydb2=# \d+ cw_complaint5
                                              Table "public.cw_complaint5"
        Column        |          Type           | Collation | Nullable | Default | Storage  | Stats target | Description 
----------------------+-------------------------+-----------+----------+---------+----------+--------------+-------------
 id                   | integer                 |           | not null |         | plain    |              | 
 row                  | smallint                |           |          |         | plain    |              | 
 document_number      | integer                 |           | not null |         | plain    |              |
...etc...
county_id            | integer                 |           |          |         | plain    |              | 
 city_id              | integer                 |           |          |         | plain    |              | 
 operator_id          | integer                 |           |          |         | plain    |              | 
Indexes:
    "cw_complaint5_pkey" PRIMARY KEY, btree (id)
Check constraints:
    "cw_complaint5_row_check" CHECK ("row" >= 0)
Foreign-key constraints:
    "cw_complaint5_city_id_fkey" FOREIGN KEY (city_id) REFERENCES cw_city5(id)
    "cw_complaint5_county_id_fkey" FOREIGN KEY (county_id) REFERENCES cw_county5(id)
    "cw_complaint5_operator_id_fkey" FOREIGN KEY (operator_id) REFERENCES cw_operator5(id)

(END)

{"id":729,"issue_description":"test","document_number":99,"api_state_code":88,"api_county_code":11,"section":22,"city_id":51,"county_id":56,"operator_id":4415}

失败的

POST

请求（更新现有行）的请求正文如下所示：

.package(url: "https://github.com/vapor/vapor.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent.git", from: "4.0.0-rc"),
.package(url: "https://github.com/vapor/fluent-postgres-driver.git", from: "2.0.0-rc")

app.databases.use(.postgres(
    hostname: Environment.get("DATABASE_HOST") ?? "localhost",
    username: Environment.get("DATABASE_USERNAME") ?? "postgres",
    password: Environment.get("DATABASE_PASSWORD") ?? "secret",
    database: Environment.get("DATABASE_NAME") ?? "mydb2"
), as: .psql)

import Fluent
import Vapor


final class Complaint: Model, Content {

    static let schema = "cw_complaint5"

    @ID(key: .id)
    var id: UUID?

    @Field(key: "issue_description")
    var issue_description: String

    // etc.
    init() { }
}

mydb2=# \d+ cw_complaint5
                                              Table "public.cw_complaint5"
        Column        |          Type           | Collation | Nullable | Default | Storage  | Stats target | Description 
----------------------+-------------------------+-----------+----------+---------+----------+--------------+-------------
 id                   | integer                 |           | not null |         | plain    |              | 
 row                  | smallint                |           |          |         | plain    |              | 
 document_number      | integer                 |           | not null |         | plain    |              |
...etc...
county_id            | integer                 |           |          |         | plain    |              | 
 city_id              | integer                 |           |          |         | plain    |              | 
 operator_id          | integer                 |           |          |         | plain    |              | 
Indexes:
    "cw_complaint5_pkey" PRIMARY KEY, btree (id)
Check constraints:
    "cw_complaint5_row_check" CHECK ("row" >= 0)
Foreign-key constraints:
    "cw_complaint5_city_id_fkey" FOREIGN KEY (city_id) REFERENCES cw_city5(id)
    "cw_complaint5_county_id_fkey" FOREIGN KEY (county_id) REFERENCES cw_county5(id)
    "cw_complaint5_operator_id_fkey" FOREIGN KEY (operator_id) REFERENCES cw_operator5(id)

(END)

{"id":729,"issue_description":"test","document_number":99,"api_state_code":88,"api_county_code":11,"section":22,"city_id":51,"county_id":56,"operator_id":4415}

---

这里的问题是

投诉

型号的ID类型是

UUID

，但在

POST

请求正文中，您传递的是

Int

值。由于您要迁移的现有项目已使用整数ID定义了数据库，因此最好的解决方案是更改模型的ID类型

由于Fluent 4尝试支持所有数据库，因此默认情况下它只支持UUID类型。您可以有一个自定义ID类型，如下所示：

@ID（自定义：“ID”，生成者：。数据库）变量ID:Int？

这将允许您的模型使用当前的数据库表结构，并在

POST

请求正文中接受整数ID

您的模型最终将如下所示：

最后一节课投诉：型号、内容{
静态let schema=“cw\u complaint5”
@ID（自定义：“ID”，生成者：。数据库）
变量id:Int？
@字段（关键字：“问题描述”）
变量问题描述：字符串
//等等。
init（）{}
}

解决方案：在PostgreSQL中序列化表：

mydb2=# ALTER TABLE cw_complaint5 DROP COLUMN id;

mydb2=# ALTER TABLE cw_complaint5 ADD COLUMN id SERIAL PRIMARY KEY;

然后，要插入一行（在xcode 11.4 vapor 4 fluentpostgresql中），请从POST请求json中删除id，例如：

{"section":1,"operator_id":4415 ... etc.}

要更新现有行，请在json中包含id。routes.swift中的以下命令同时处理插入和更新：

app.post("complaint") { req -> EventLoopFuture<Complaint> in
    let complaint = try req.content.decode(Complaint.self)
    if let id = complaint.id {
        print("60p \(id)") // Optional(6005)
    }
    return complaint.save(on: req.db)
        .map { complaint }
}

app.post（“投诉”）{req->EventLoopFuture
让投诉=尝试请求内容解码（投诉.self）
如果let id=complaint.id{
打印（“60p\（id）”//可选（6005）
}
返回投诉。保存（on:req.db）
.map{投诉}
}

您可以显示POST端点的代码吗？好的，这里是（成功的）GET和（不成功的）POST:app.GET（“投诉”）{req in complaint.query（on:req.db）.all（）}app.POST（“投诉”）{req->EventLoopFuture in let complaint=try req.content.decode（complaint.self）return complaint.create（on:req.db）.map{complaint}我看到它做了一个create，所以我不希望它更新现有的行。如果我从json请求体中删除id并希望它插入一行，我得到：{“error”：true，“reason”：“server:column\“id”的类型是integer，但表达式的类型是uuid（transformAssignedExpr）}我尝试了模型中id的各种排列。这是生成唯一接受的：@id（键：.id）变量id:UUID？如果数据库中的

id

列已经是autoincrement integer，那么您不应该将模型的id更改为

UUID

。要流畅地使用autoincrement，据我所知，您只需将您的id标记为可自动生成的，例如

@id（自定义：“id”，generatedBy:.database）var id:Int？

按照您的建议对id进行编码，并尝试POST插入一行（json请求中没有id），我得到“服务器：列\“id\”中的null值违反了非null约束（ExecConstraints）”