I'm creating a Flask app with SQLAlchemy.
In Odoo ORM, we have a column or a field named 'Selection'.
I wanna do something great like this into SQLAlchemy:
STATUS = [('admin','Admin'),('guest','Guest')]
status = db.Column(db.Selection, selection=STATUS)
With Odoo's ORM:
status = fields.Selection(STATUS, default='guest')
I don't wanna create a new Model to store these : 'admin','guest','superadmin'.
Thanks for all
You can use SQLAlchemy enum. Check SQLAlchemy 1.3 Documentation here: class sqlalchemy.types.Enum(*enums, **kw)
class Status(enum.Enum):
ADMIN = "admin"
GUEST = "guest"
class MyTable(db.Model):
id = db.Column(db.Integer, primary_key = True)
status = db.Column(db.Enum(Status), default=Status.GUEST)
Related
I am trying to use the dajngo-import-export package to export data from two tables with a one to many relationship. I have a custom ForeignKeyWidget class that overrides the get_queryset method.
The problem is that the export returns an empty field - no errors, just an empty field. I also tried just using the ForeignKeyWidget without the custom class/get_queryset - but I get the same result.
Does anyone see what I'm doing wrong here?
#admin.py
from import_export import resources
from import_export.fields import Field
from import_export.widgets import ForeignKeyWidget
class SlateDocResource(resources.ModelResource):
actbreaks = Field(
column_name="actbreaks",
attribute="id",
widget=ActBreaksForeignKeyWidget(ActTimecodes, "slatedoc_id"),
)
class Meta:
model = SlateDoc
fields = [
"actbreaks",
]
class ActBreaksForeignKeyWidget(ForeignKeyWidget):
def get_queryset(self, value, row, *args, **kwargs):
qs = ActTimecodes.objects.filter(slatedoc_id=self.pk)
print(qs.values())
return qs
#models.py
class SlateDoc(models.Model):
#primary Model - fields not listed here.
class ActTimecodes(models.Model):
#Secondary model - every slatedoc can have multiple instances of ActTimecodes
slatedoc = models.ForeignKey(
SlateDoc,
on_delete=models.CASCADE,
related_name="acts"
)
act_number = models.IntegerField(verbose_name="Act", default=1)
tc_in = models.CharField(max_length=11, default="00:00:00:00")
tc_out = models.CharField(max_length=11, default="00:00:00:00")
dur = models.CharField(max_length=11, default="00:00:00:00")
objects = ActTimecodesQuerySet.as_manager()
class Meta:
ordering = ["act_number", "tc_in", "tc_out"]
#version info
"python_version": { "version": ==3.10" }
"django": { "version": "==4.1.1" },
"django-import-export": { "version": "==2.8.0"},
Here is the solution that I figured out.
The answer is very simple compared to what I was attempting to do - using the ForeignKey was totally unnecessary.
#admin.py
class SlateDocResource(resources.ModelResource):
actbreaks = Field(column_name="Act Breaks")
def dehydrate_actbreaks(self, slatedoc):
actbreaks = []
count = 1
for x in ActTimecodes.objects.filter(slatedoc_id=slatedoc.id):
tc_in = f"{count}_in"
tc_out = f"{count}_out"
duration = f"{count}_dur"
actbreak = {tc_in: x.tc_in, tc_out: x.tc_out, duration: x.dur}
actbreaks.append(actbreak)
count += 1
return actbreaks
the code above returns each actbreak as a dict in a list:
[{'tc_1_in': '01:00:00:00', 'tc_1_out': '01:13:34:00', 'act_1_dur': '00:13:34;00'}, {'tc_2_in': '01:13:36:00', 'tc_2_out': '01:19:03:00', 'act_2_dur': '00:05:26;28'}, {'tc_3_in': '01:19:05:00', 'tc_3_out': '01:26:13:00', 'act_3_dur': '00:07:08;02'}, {'tc_4_in': '01:26:15:00', 'tc_4_out': '01:31:16:00', 'act_4_dur': '00:05:01;02'}, {'tc_5_in': '01:31:18:00', 'tc_5_out': '01:37:39:00', 'act_5_dur': '00:06:21;00'}, {'tc_6_in': '01:37:41:00', 'tc_6_out': '01:44:10:00', 'act_6_dur': '00:06:29;00'}]
I have a model with multiple fields being checked for uniqueness:
class AudQuestionList(BaseTimeStampModel):
aud_ques_list_id = models.AutoField(primary_key=True,...
aud_ques_list_num = models.CharField(max_length=26,...
aud_ques_list_doc_type = models.ForeignKey(DocType,...
short_text = models.CharField(max_length=55,...
aud_scope_standards = models.ForeignKey(ScopeStandard, ...
aud_freqency = models.ForeignKey(AuditFrequency, ...
aud_process = models.ForeignKey(AuditProcesses, ...
unique_together = [['aud_scope_standards', 'aud_freqency', 'aud_process',],]
My model form is as described below:
class CreateAudQuestionListForm(forms.ModelForm):
class Meta:
model = AudQuestionList
fields = ('aud_ques_list_doc_type', 'aud_scope_standards', 'aud_freqency', 'aud_process', 'short_text', ...
def validate_unique(self):
try:
self.instance.validate_unique()
except ValidationError:
self._update_errors({'aud_scope_standards': _('Record exists for the combination of key values.')})
The scenario works perfectly well, only that the field names (labels) itself are missing from the message.
Is there a way to add the field names to the message above, say something like:
Record exists for the combination of key fields + %(field_labels)s.
I'm stuck on a pretty simple issue with peewee-async regarding JOINs, or perhaps I need to use a subquery, or prefetch... I can't figure it out what kind of query I need to do.
I have 2 database tables (parent/child):
class Group(PeeweeModel):
id = peewee.AutoField()
name = peewee.TextField()
class Channel(PeeweeModel):
id = peewee.AutoField()
name = peewee.TextField()
group = peewee.ForeignKeyField(Group, backref="channels")
I need to fetch 1 group object, and this object has multiple channel objects.
I tried:
q = Group.select(Group, Channel).join(Channel)
But my backref 'channels' is always a ModelQuery instance, not the actual resultset.
Full code
import asyncio
import peewee
import peewee_async
from peewee_async import Manager, PooledPostgresqlDatabase
database = PooledPostgresqlDatabase('test', max_connections=4, user='postgres', password='', host='127.0.0.1')
objects = peewee_async.Manager(database)
class PeeweeModel(peewee.Model):
class Meta:
database = database
class Group(PeeweeModel):
id = peewee.AutoField()
name = peewee.TextField()
class Channel(PeeweeModel):
id = peewee.AutoField()
name = peewee.TextField()
group = peewee.ForeignKeyField(Group, backref="channels")
Group.create_table()
Channel.create_table()
database.set_allow_sync(False)
async def handler():
# create 1 group object
group = await objects.create(Group, name="TestGroup")
# create 2 channel objects, assign to group
await objects.create(Channel, name="TestName1", group=group)
await objects.create(Channel, name="TestName2", group=group)
# Query 1 group, and hopefully it will have the channels
q = Group.select(Group, Channel).join(Channel)
results = await objects.execute(q)
for result in results:
print(result.channels) # problem: Channels is not a list of channel objects, but a `ModelSelect` instead
with objects.allow_sync():
Channel.drop_table(True)
Group.drop_table(True)
loop = asyncio.get_event_loop()
loop.run_until_complete(handler())
loop.close()
I was able to get help from an expert™ and the solution is to use prefetch():
async def handler():
# create 1 group object
group = await objects.create(Group, name="TestGroup")
# create 2 channel objects, assign to group
await objects.create(Channel, name="TestName", group=group)
await objects.create(Channel, name="TestName", group=group)
# Query 1 group, and hopefully it will have the channels
q = Group.select(Group)
groups = await objects.prefetch(q, Channel.select(Channel))
for group in groups:
print(group, group.channels) # channels is a list of channels.
with objects.allow_sync():
Channel.drop_table(True)
Group.drop_table(True)
Peewee will figure out the relationship (backref) by itself.
I am trying to create a one-to-one mapping using Pony ORM.
class ApplierIngress(ApplierObjectMapper.db.Entity):
correlation_id = orm.PrimaryKey(str)
ticket_number = orm.Required(str)
username = orm.Required(str)
status = orm.Required(str)
request_date = orm.Required(datetime)
class ApplierResult(ApplierObjectMapper.db.Entity):
correlation_id = orm.Required(ApplierIngress)
result = orm.Required(orm.LongStr)
request_date = orm.Required(datetime)
It throws error while generating the mapping
pony.orm.core.ERDiagramError: Reverse attribute for ApplierResult.correlation_id not found
I want correlation_id in ApplierResult table be the foreign key referencing to correlation_id in ApplierIngress table
Please let me know what am I doing wrong?
As error said you need to specify reverse attribute. Entities is not just Tables.
class ApplierIngress(ApplierObjectMapper.db.Entity):
correlation_id = orm.PrimaryKey(str)
ticket_number = orm.Required(str)
username = orm.Required(str)
status = orm.Required(str)
request_date = orm.Required(datetime)
result_id = orm.Optional('ApplierResult') # this attribute should be added
class ApplierResult(ApplierObjectMapper.db.Entity):
correlation_id = orm.Required(ApplierIngress)
result = orm.Required(orm.LongStr)
request_date = orm.Required(datetime)
Since this class is not yet declared you should use it as string or lambda
result_id = orm.Optional('ApplierResult')
result_id = orm.Optional(lambda: ApplierResult)
See here
Am using the featuretools documentation to learn entityset and am currently getting error KeyError: 'Variable: device not found in entity' for the following piece of code:
import featuretools as ft
data = ft.demo.load_mock_customer()
customers_df = data["customers"]
customers_df
sessions_df = data["sessions"]
sessions_df.sample(5)
transactions_df = data["transactions"]
transactions_df.sample(10)
products_df = data["products"]
products_df
### Creating an entity set
es = ft.EntitySet(id="transactions")
### Adding entities
es = es.entity_from_dataframe(entity_id="transactions", dataframe=transactions_df, index="transaction_id", time_index="transaction_time", variable_types={"product_id": ft.variable_types.Categorical})
es
es["transactions"].variables
es = es.entity_from_dataframe(entity_id="products",dataframe=products_df,index="product_id")
es
### Adding new relationship
new_relationship = ft.Relationship(es["products"]["product_id"],
es["transactions"]["product_id"])
es = es.add_relationship(new_relationship)
es
### Creating entity from existing table
es = es.normalize_entity(base_entity_id="transactions",
new_entity_id="sessions",
index = "session_id",
additional_variables=["device",customer_id","zip_code"])
This is as per the URL - https://docs.featuretools.com/loading_data/using_entitysets.html
From the API es.normalise_entity it appears that the function would create new entity 'sessions' with index as 'session_id', and rest of the 3 variables however the error is:
C:\Users\s_belvi\AppData\Local\Continuum\Anaconda2\lib\site-packages\featuretools\entityset\entity.pyc in _get_variable(self, variable_id)
250 return v
251
--> 252 raise KeyError("Variable: %s not found in entity" % (variable_id))
253
254 #property
KeyError: 'Variable: device not found in entity'
Do we need to create entity "sessions" separately before using es.normalize_entity? Looks like something syntactically has gone wrong in the flow, some minor mistake..
The error here arises from device not being a column in your transactions_df. The "transactions" table referenced in that page of the documentation has more columns than demo.load_mock_customer in its dictionary form. You can find the rest of the columns using the return_single_table argument. Here's a full working example of normalize_entity which is only slightly modified from the code that you tried:
import featuretools as ft
data = ft.demo.load_mock_customer(return_single_table=True)
es = ft.EntitySet(id="Mock Customer")
es = es.entity_from_dataframe(entity_id="transactions",
dataframe=data,
index="transaction_id",
time_index="transaction_time",
variable_types={"product_id": ft.variable_types.Categorical})
es = es.normalize_entity(base_entity_id="transactions",
new_entity_id="sessions",
index = "session_id",
additional_variables=["device","customer_id","zip_code"])
This will return an EntitySet with two Entities and one Relationship:
Entityset: Mock Customer
Entities:
transactions [Rows: 500, Columns: 8]
sessions [Rows: 35, Columns: 5]
Relationships:
transactions.session_id -> sessions.session_id