自定义 Django 二进制字段和 SQL Server 2008

Question

我有一张小桌子：

CREATE TABLE [organization_division] (
[id] int IDENTITY (1, 1) NOT NULL PRIMARY KEY,
[uuid] binary(16) NOT NULL
)

我可以用 SQL 查询插入一条记录：

INSERT INTO [organization_division] ([uuid]) VALUES (0x244c71c6c9444f38b67ab1dcfbb5fc32)

这个表的 Django 模型是：

from apps.lib.fields import GUIDField

class Division(models.Model):
    uuid = GUIDField() 

GUIDField 是我创建自定义字段的尝试：

class GUIDField(models.Field):    
    description = "GUID binary field"
    __metaclass__ = models.SubfieldBase

    def __init__(self, *args, **kwargs):
        kwargs['max_length'] = 16
        super(GUIDField, self).__init__(*args, **kwargs)

    def db_type(self, connection):
        return 'binary(16)'

我需要将 16 字节的二进制数据从 ORM 实例传递到数据库。很可能我必须在 SQL Server 端获得一个不带引号的字符串，后跟 0x ......但是如何？

我正在使用 unixodbc、pyodbc、django-odbc。

Answer 1

from django.db import models
import pyodbc

class GUIDField(models.Field):    
    description = "GUID binary field"
    __metaclass__ = models.SubfieldBase

    def __init__(self, *args, **kwargs):
        kwargs['max_length'] = 16
        super(GUIDField, self).__init__(*args, **kwargs)

    def db_type(self, connection):
        return 'binary(16)'

    def get_db_prep_value(self, value):
        if value is None:
            return None
        return pyodbc.BINARY(value)