How to Interact with Multiple Temporary Tables with Identical Schemas in Django?

Single Django Model for Multiple Temporary Tables

When working with MySQL databases, it is possible to have multiple temporary tables with identical schemas but dynamic names. To interact with these tables in Django, you can employ a factory function that generates models with a specified db_table value.

Dynamic Model Creation

The following code demonstrates how to create a model dynamically based on a database table name:

<code class="python">def getModel(db_table):
    class MyClass(models.Model):
        # Define model fields here...

        class Meta:
            db_table = db_table

    return MyClass</code>

By calling getModel(db_table), you obtain a model that uses the specified db_table name. For instance, to retrieve data from the table 29345794_table, you can use:

<code class="python">newClass = getModel('29345794_table')
results = newClass.objects.filter(...)</code>

Custom Metaclass for Dynamic Class Names

Initially, Django caches the metaclass information for each class based on its name. To circumvent this limitation, you can employ a custom metaclass that modifies the class name at runtime:

<code class="python">def getModel(db_table):
    class MyClassMetaclass(models.base.ModelBase):
        def __new__(cls, name, bases, attrs):
            name += db_table
            return models.base.ModelBase.__new__(cls, name, bases, attrs)

    class MyClass(models.Model):
        __metaclass__ = MyClassMetaclass

        class Meta:
            db_table = db_table

    return MyClass</code>

Alternative Solution: Dynamic db_table Setting

Instead of creating new models each time, you can dynamically modify the db_table attribute of an existing model:

<code class="python">MyModel._meta.db_table = '10293847_table'
results = MyModel.objects.all()</code>

This approach allows you to dynamically switch between different table names for the same model.

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