如何使用sqlalchemy利用sqlite清单类型/类型关联?

好吧,我想到的是:

根据定义自定义列类型 http://www.sqlalchemy.org/docs/reference/sqlalchemy/types.html#custom-types

文档和一些试用版的结合;错误告诉我:

class MyDuckType(sqlalchemy.types.TypeDecorator):
    """
    SQLALchemy custom column type, designed to let sqlite handle the typing 
    using 'numeric affinity' which intelligently handles both numbers and strings
    """
    impl = sqlite.NUMERIC

    def bind_processor(self, dialect):
        #function for type coercion during db write
        return None #ie pass value as-is, let sqlite do the typing

    def result_processor(self, dialect, coltype):
        #function for type coercion during db read
        return None #ie pass value as sqlite has stored it, should be ducktyped already

    def process_bind_param(self, value, dialect):
        #any changes to an individual value before store in DN
        return value

    def process_result_value(self, value, dialect):
        #any changes to an individual value after retrieve from DB
        return value

    def copy(self):
        #not quite sure what this is for
        return MyDuckType()

当前的sqlalchemy方言类型返回到bind\u处理器中的\u float,这就是我之前得到错误的原因。i、 m.v.v.h.o.,这是个虫子。

对于我的加分:在my metadata.reflect()代码中将列类型手动设置为MyDuckType:

def get_database_tables(engine):
    meta = MetaData()
    meta.reflect(bind=engine)
    tables = meta.raw_tables
    for tbl in tables.values():
        for col in tbl.c:
            col.type = MyDuckType()
    return tables

似乎对我有用。有什么建议/改进吗?

基本上,如果我设置列的 作为“数字”,它将回避 键入整数或浮点数来存储它们 如果我愿意的话。

123 从 '123' .