StringField(Field): def __init__(self, name=None, primary_key=False, default=None, ddl='varchar(100)'): super().__init__(name, ddl, primary_key, default) 注意到 Model 只是一个基类，如何将具体的子类如 User 的映射信息读取 出来呢？答案就是通过 default=next_id, ddl='varchar(50)') email = StringField(ddl='varchar(50)') passwd = StringField(ddl='varchar(50)') admin = BooleanField() name = StringField(ddl='varchar(50)') StringField(ddl='varchar(500)') created_at = FloatField(default=time.time) class Blog(Model): __table__ = 'blogs' id = StringField(primary_key=True, default=next_id, ddl='varchar(50)')

point). MySQL 8.0 introduced significant performance enhancements for DDL operations [https://dev.mysql.com/doc/refman/en/innodb-online-ddl-operations.html], making them more efficient and reducing the need databases that support DDL transactions (SQLite and PostgreSQL), all migration operations will run inside a single transaction by default. In contrast, if a database doesn’t support DDL transactions (e.g. RunPython will have their original uuid’s overwritten. Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use

point). MySQL 8.0 introduced significant performance enhancements for DDL operations [https://dev.mysql.com/doc/refman/en/innodb-online-ddl-operations.html], making them more efficient and reducing the need databases that support DDL transactions (SQLite and PostgreSQL), all migration operations will run inside a single transaction by default. In contrast, if a database doesn’t support DDL transactions (e.g. RunPython will have their original uuid’s overwritten. Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use

point). MySQL 8.0 introduced significant performance enhancements for DDL operations [https://dev.mysql.com/doc/refman/en/innodb-online-ddl-operations.html], making them more efficient and reducing the need databases that support DDL transactions (SQLite and PostgreSQL), all migration operations will run inside a single transaction by default. In contrast, if a database doesn’t support DDL transactions (e.g. RunPython will have their original uuid’s overwritten. Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use

RunPython will have their original uuid’s overwritten. Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use atomic attribute doesn’t have an effect on databases that don’t support DDL transactions (e.g. MySQL, Oracle). (MySQL’s atomic DDL statement support refers to individual statements rather than multiple ignores an explicit null option on fields that have the empty string as a possible value and generates DDL as if null=True. When fetching from the database, it is assumed that a NULL value in one of these fields

RunPython will have their original uuid’s overwritten. Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use atomic attribute doesn’t have an effect on databases that don’t support DDL transactions (e.g. MySQL, Oracle). (MySQL’s atomic DDL statement support refers to individual statements rather than multiple ignores an explicit null option on fields that have the empty string as a possible value and generates DDL as if null=True. When fetching from the database, it is assumed that a NULL value in one of these fields

RunPython will have their original uuid’s overwritten. Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use atomic attribute doesn’t have an effect on databases that don’t support DDL transactions (e.g. MySQL, Oracle). (MySQL’s atomic DDL statement support refers to individual statements rather than multiple ignores an explicit null option on fields that have the empty string as a possible value and generates DDL as if null=True. When fetching from the database, it is assumed that a NULL value in one of these fields

databases that support DDL transactions (SQLite and PostgreSQL), all migration operations will run inside a single transaction by default. In contrast, if a database doesn’t support DDL transactions (e.g. Documentation, Release 4.0.11.dev20230214085346 Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use atomic attribute doesn’t have an effect on databases that don’t support DDL transactions (e.g. MySQL, Oracle). (MySQL’s atomic DDL statement support refers to individual statements rather than multiple

databases that support DDL transactions (SQLite and PostgreSQL), all migration operations will run inside a single transaction by default. In contrast, if a database doesn’t support DDL transactions (e.g. RunPython will have their original uuid’s overwritten. Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use atomic attribute doesn’t have an effect on databases that don’t support DDL transactions (e.g. MySQL, Oracle). (MySQL’s atomic DDL statement support refers to individual statements rather than multiple

databases that support DDL transactions (SQLite and PostgreSQL), all migration operations will run inside a single transaction by default. In contrast, if a database doesn’t support DDL transactions (e.g. RunPython will have their original uuid’s overwritten. Non-atomic migrations On databases that support DDL transactions (SQLite and PostgreSQL), migrations will run inside a transaction by default. For use atomic attribute doesn’t have an effect on databases that don’t support DDL transactions (e.g. MySQL, Oracle). (MySQL’s atomic DDL statement support refers to individual statements rather than multiple