0
我正在编写一个Django应用程序,该应用程序使用现有遗留数据与重新映射的表和关系。我已经给出了一个包含表之间的主 - 外键关系的表,但是无法理解如何将它适配到Django模型。Django模型和主要 - 外键关系
例如,表country_metrics
被定义为
+-------------+---------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------+---------------+------+-----+---------+-------+
| ContractNum | varchar(10) | NO | | NULL | |
| fips | varchar(5) | NO | | NULL | |
| metric_id | int(10) | NO | | NULL | |
| time_id | int(10) | NO | | NULL | |
| value | decimal(12,3) | NO | | NULL | |
| eff_date | date | NO | | NULL | |
| exp_date | date | YES | | NULL | |
+-------------+---------------+------+-----+---------+-------+
,我已经被赋予其在类
class ContractCountyMetrics(models.Model):
contractnum = models.CharField(max_length=10L, db_column='ContractNum', primary_key = true) # Field name made lowercase.
fips = models.CharField(max_length=5L)
metric_id = models.IntegerField()
time_id = models.IntegerField()
value = models.DecimalField(max_digits=14, decimal_places=3)
eff_date = models.DateField()
exp_date = models.DateField(null=True, blank=True)
contractKey = models.ForeignKey(Contracts)
fipsKey = models.ForeignKey(Counties)
metricKey = models.ForeignKey(Metrics)
timeKey = models.ForeignKey(Time)
class Meta:
db_table = 'txn_contract_county_metrics'
unique_together("contractKey", "fipsKey", "metricKey", "timeKey")
被建模的
ContractNum primary key, foreign key references table contracts
fips primary key, foreign key references table country
metric_id primary key, foreign key references table metrics
time_id primary key, foreign key references table time
的关系映射从我读的,unique_together
基本上模拟一个复合键,并允许多个字段具有主键功能。我在正确的轨道上吗?
谢谢。我刚刚与数据架构师就此问题进行了联系,并可能会导致一些关系性的重新思考。 – Jason