Django 提交行时外键约束错误

Question

我刚刚创建了一个Django项目并在mysql中直接添加了2个：

1）金融控股（tbl_holdings）

2) 服务提供商 (tbl_holdings_service_providers)

他们在我的 Sql 中的两个数据定义是：

tbl_holdings

CREATE TABLE `tbl_holdings` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `item_code` varchar(5) NOT NULL,
  `product_name` varchar(45) NOT NULL,
  `service_provider` varchar(100) NOT NULL,
  `account_details` varchar(100) NOT NULL,
  `purchase_cost` int(15) NOT NULL,
  `current_value` int(15) NOT NULL,
  `purchase_date` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `item_code_UNIQUE` (`item_code`),
  KEY `fk_service_provider_name_idx` (`service_provider`),
  CONSTRAINT `fk_service_provider` FOREIGN KEY (`service_provider`) REFERENCES `tbl_holdings_service_providers` (`provider_name`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1

tbl_holdings_service_providers

CREATE TABLE `tbl_holdings_service_providers` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `provider_name` varchar(100) NOT NULL,
  `updated_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `INDEX` (`provider_name`)
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=latin1

我在 Django models.py 中创建了相关的 model

class TblHoldings(models.Model):
    item_code = models.CharField(unique=True, max_length=5)
    product_name = models.CharField(max_length=45)
    service_provider = models.ForeignKey('TblHoldingsServiceProviders', models.DO_NOTHING, related_name='service_provider',db_column='service_provider')
    account_details = models.CharField(max_length=100)
    purchase_cost = models.IntegerField()
    current_value = models.IntegerField()
    purchase_date = models.DateTimeField(blank=True, null=True)
    updated_at = models.DateTimeField(blank=True, null=True)
    created_at = models.DateTimeField(blank=True, null=True)

    class Meta:
        verbose_name = 'Holding'
        verbose_name_plural = 'Holdings'
        managed = False
        db_table = 'tbl_holdings'

class TblHoldingsServiceProviders(models.Model):
    provider_name = models.CharField(max_length=100)
    updated_at = models.DateTimeField(blank=True, null=True)
    created_at = models.DateTimeField(blank=True, null=True)

    class Meta:
        verbose_name = "Lookup For Service Provider"
        verbose_name_plural = 'Lookup For Service Providers'
        managed = False
        db_table = 'tbl_holdings_service_providers'

admin.py 中的代码是

@admin.register(TblHoldings)
class HoldingsAdmin(admin.ModelAdmin):
    list_display = ('item_code', 'product_name', 'service_provider', 'current_value', 'created_at')
    ordering = ('purchase_date',)
    search_fields = ('product_name',)

@admin.register(TblHoldingsServiceProviders)
class HoldingsServiceProviderAdmin(admin.ModelAdmin):
    list_display = ('id', 'provider_name', 'created_at')
    ordering = ('created_at',)
    search_fields = ('provider_name',)

在尝试添加控股时，我收到以下错误：与外键约束有关

IntegrityError at /admin/app_fin/tblholdings/add/ (1452, '无法添加或更新子行：外键约束失败 ( _finance , CONSTRAINT tbl_holdings FOREIGN KEY ( service_provider ) tbl_holdings_service_providers fk_service_provider provider_name ) ON DELETE NO ACTION ON UPDATE )') 请求方法：POST 请求 URL：admin/app_fin/tblholdings/add/ Django 版本：2.2.7 异常类型：IntegrityError 异常值：（1452，'不能添加或更新外键约束失败： _finance . tbl_holdings , CONSTRAINT fk_service_provider FOREIGN KEY ( service_provider ) REFERENCES tbl_holdings_service_providers ( provider_name ) ON DELETE NO ACTION ON UPDATE )') 异常位置：/root//venv/lib/python3.6/site-packages/MySQLdb/connections.py in查询，第 231 行 Python 可执行文件：/root//venv/bin/python Python 版本：3.6.8 ZA7F5F35426B9274 11FC9231B56382173Z 路径：['/root//project_'，'/root//venv/lib/python36.zip'，'/root//venv/libremoved/python3.6'，'/root//venv/lib/python3 .6/lib-dynload', '/usr/lib/python3.6', '/root/_fin/venv/lib/python3.6/site-packages'] 服务器时间：2019 年 11 月 12 日星期二 09:51： 28 +0000

有人可以指出我做错了什么。

Answer 1

看起来您使用的外键不是主键。 你可以试试这个

CREATE TABLE `tbl_holdings` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `item_code` varchar(5) NOT NULL,
  `product_name` varchar(45) NOT NULL,
  `service_provider` varchar(100) NOT NULL,
  `account_details` varchar(100) NOT NULL,
  `purchase_cost` int(15) NOT NULL,
  `current_value` int(15) NOT NULL,
  `purchase_date` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `item_code_UNIQUE` (`item_code`),
  KEY `fk_service_provider_name_idx` (`service_provider`),
  CONSTRAINT `fk_service_provider` FOREIGN KEY (`service_provider`) REFERENCES `tbl_holdings_service_providers` (`provider_id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1