Question

我有一个使用Postgresql 11数据库的Peewee 3.6（带烧瓶）应用程序。在使用create_tables创建模型的过程中，数据库会抛出relation "table" does not exist是否存在尚未创建引用关系的外键。我如何配置数据库或peewee在数据库初始化期间忽略它们或在以后的更改中创建FK？

这是我连接到数据库的方式：

from playhouse.pool import PooledPostgresqlExtDatabase
from playhouse.pool import PooledSqliteDatabase

def database_init(app, models):
    logging.info("Init database connection: %s %s" % (app.config["DATABASE"], app.config["DATABASE_NAME"]))
    if app.config["DATABASE"] == "postgresql":
        database = PooledPostgresqlExtDatabase(app.config["DATABASE_NAME"], max_connections=16, stale_timeout=300, **app.config["DATABASE_AUTH"])

    elif app.config["DATABASE"] == "sqlite":
        database = PooledSqliteDatabase(app.config["DATABASE_PATH"], pragmas={
            "journal_mode": "wal",
            "cache_size": -1024 * 64,
            "foreign_keys": 1
        })
    else:
        raise RuntimeError("No database set or invalid")
    try:
        DB.initialize(database)
    except:
        logging.exception("Could not initialize database")


def database_connect():
    try:
        DB.connect()
    except:
        logging.exception("Could not connect to database")

app.config["DATABASE_AUTH"]仅包含必要的user，password，host和port字段。函数database_connect稍后将由应用程序的其余部分调用。

创建初始表非常简单：

def create_tables(app, models):
    try:
        DB.create_tables(models, safe=True)
    except:
        logging.exception("Could not create tables")

其中models是模型的列表，按初始化顺序从不同的模块（例如不依依顺序。

我最复杂的模型使用自引用，但是我的大多数模型只有一个owner字段，该字段引用了users。

对于第一个模型，它会产生这样的错误，包括create语句：

STATEMENT:  CREATE TABLE IF NOT EXISTS "category" ("id" SERIAL NOT NULL PRIMARY KEY, "created" TIMESTAMP NOT NULL, "edited" TIMESTAMP NOT NULL, "is_deleted" BOOLEAN NOT NULL, "owner_id" INTEGER, "name" TEXT NOT NULL, "comment" TEXT NOT NULL, "is_archived" BOOLEAN NOT NULL, "is_protected" BOOLEAN NOT NULL, "order" INTEGER NOT NULL, "path" TEXT NOT NULL, "parent_id" INTEGER, FOREIGN KEY ("owner_id") REFERENCES "user" ("id"), FOREIGN KEY ("parent_id") REFERENCES "category" ("id"))

ERROR:  current transaction is aborted, commands ignored until end of transaction block

但是对于这个特定的查询，我的模型看起来像这样，包括所有引用类：

class BaseModel(peewee.Model):
    """ Peewee's Base model
    """
    class Meta:
        database = DB

class BaseUser(BaseModel):
    """ Base model for user
    """
    class Meta:
        table_name = "users"  # 'user' is reserved in most of dbs
    name = peewee.TextField(null=False, unique=True)
    password = peewee.TextField(null=False)
    pass

class BaseDocumentModel(BaseModel):
    created = peewee.DateTimeField(null=False, default=datetime.now)
    edited = peewee.DateTimeField(null=False, default=datetime.now, index=True)
    is_deleted = peewee.BooleanField(null=False, default=False)

    owner = peewee.ForeignKeyField(BaseUser, null=True)

    def changed(self):
        self.edited = datetime.now()

class Category(components.BaseDocumentModel):
    name = peewee.TextField()
    comment = peewee.TextField(default="")
    is_archived = peewee.BooleanField(default=False)
    is_protected = peewee.BooleanField(default=False)
    order = peewee.IntegerField(default=0)
    path = peewee.TextField()
    parent = peewee.ForeignKeyField("self", backref="children", null=True)

创建具有外键引发关系的表

0 个答案: