[英]Python peewee foreign key constraint incorrectly formed
I'm currently working on a python project using peewee to connect to MySQLDatabase.我目前正在使用 peewee 连接到 MySQLDatabase 的 python 项目。
If I want to create a table using database.create_tables(tables=[])
(create_table does not work)如果我想使用
database.create_tables(tables=[])
创建一个表(create_table 不起作用)
I get the following error message from my logger:我从我的记录器中收到以下错误消息:
ERROR session[5924]: (1005, 'Can't create table example_database.example_table (errno: 150 "Foreign key constraint is incorrectly formed")')
ERROR session[5924]: (1005, 'Can't create table example_database.example_table (errno: 150 "外键约束的格式不正确")')
example_table is specified as: example_table 指定为:
class Example_Table(BaseModel):
id = PrimaryKeyField()
example_table2 = ForeignKeyField(Modul)
class Meta:
db_table = 'Example_Table'
BaseModel is defined as follows: BaseModel 定义如下:
class BaseModel(Model):
class Meta:
database = database
and database is my MySQLDatabase Object.和数据库是我的 MySQLDatabase 对象。
The Problem is, why doesnt the foreign key constraint work and why are the tables all saved in Lowercase, but I defined them in Uppercase问题是,为什么外键约束不起作用,为什么表都以小写形式保存,但我用大写形式定义了它们
If I run the program again, It creates the tables but gives me a duplicate key_name error如果我再次运行该程序,它会创建表但给我一个重复的 key_name 错误
Version: peewee==3.0.17版本:peewee==3.0.17
So, in peewee 3.x, you use table_name
rather than db_table
to explicitly declare a non-default table name.因此,在 peewee 3.x 中,您使用
table_name
而不是db_table
来显式声明非默认表名。
I ran some sample code locally to give a test:我在本地运行了一些示例代码来进行测试:
class User(Model):
username = TextField()
class Meta:
database = db
table_name = 'UserTbl'
class Note(Model):
user = ForeignKeyField(User, backref='notes')
content = TextField()
class Meta:
database = db
table_name = 'NoteTbl'
I created the tables and checked the SQL output, which looks correct to me:我创建了表并检查了 SQL 输出,这对我来说是正确的:
CREATE TABLE IF NOT EXISTS `UserTbl` (`id` INTEGER AUTO_INCREMENT NOT NULL PRIMARY KEY, `username` TEXT NOT NULL)
CREATE TABLE IF NOT EXISTS `NoteTbl` (`id` INTEGER AUTO_INCREMENT NOT NULL PRIMARY KEY, `user_id` INTEGER NOT NULL, `content` TEXT NOT NULL, FOREIGN KEY (`user_id`) REFERENCES `UserTbl` (`id`))
CREATE INDEX `note_user_id` ON `NoteTbl` (`user_id`)
Hope that helps.希望有帮助。
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