dify/api/models/dataset.py
Poorandy 8a80af39c9
refactor(models&tools): switch to dify_config in models and tools. (#6394)
Co-authored-by: Poorandy <andymonicamua1@gmail.com>
2024-07-17 22:26:18 +08:00

683 lines
28 KiB
Python

import base64
import hashlib
import hmac
import json
import logging
import os
import pickle
import re
import time
from json import JSONDecodeError
from sqlalchemy import func
from sqlalchemy.dialects.postgresql import JSONB
from configs import dify_config
from core.rag.retrieval.retrival_methods import RetrievalMethod
from extensions.ext_database import db
from extensions.ext_storage import storage
from models import StringUUID
from models.account import Account
from models.model import App, Tag, TagBinding, UploadFile
class Dataset(db.Model):
__tablename__ = 'datasets'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='dataset_pkey'),
db.Index('dataset_tenant_idx', 'tenant_id'),
db.Index('retrieval_model_idx', "retrieval_model", postgresql_using='gin')
)
INDEXING_TECHNIQUE_LIST = ['high_quality', 'economy', None]
id = db.Column(StringUUID, server_default=db.text('uuid_generate_v4()'))
tenant_id = db.Column(StringUUID, nullable=False)
name = db.Column(db.String(255), nullable=False)
description = db.Column(db.Text, nullable=True)
provider = db.Column(db.String(255), nullable=False,
server_default=db.text("'vendor'::character varying"))
permission = db.Column(db.String(255), nullable=False,
server_default=db.text("'only_me'::character varying"))
data_source_type = db.Column(db.String(255))
indexing_technique = db.Column(db.String(255), nullable=True)
index_struct = db.Column(db.Text, nullable=True)
created_by = db.Column(StringUUID, nullable=False)
created_at = db.Column(db.DateTime, nullable=False,
server_default=db.text('CURRENT_TIMESTAMP(0)'))
updated_by = db.Column(StringUUID, nullable=True)
updated_at = db.Column(db.DateTime, nullable=False,
server_default=db.text('CURRENT_TIMESTAMP(0)'))
embedding_model = db.Column(db.String(255), nullable=True)
embedding_model_provider = db.Column(db.String(255), nullable=True)
collection_binding_id = db.Column(StringUUID, nullable=True)
retrieval_model = db.Column(JSONB, nullable=True)
@property
def dataset_keyword_table(self):
dataset_keyword_table = db.session.query(DatasetKeywordTable).filter(
DatasetKeywordTable.dataset_id == self.id).first()
if dataset_keyword_table:
return dataset_keyword_table
return None
@property
def index_struct_dict(self):
return json.loads(self.index_struct) if self.index_struct else None
@property
def created_by_account(self):
return db.session.get(Account, self.created_by)
@property
def latest_process_rule(self):
return DatasetProcessRule.query.filter(DatasetProcessRule.dataset_id == self.id) \
.order_by(DatasetProcessRule.created_at.desc()).first()
@property
def app_count(self):
return db.session.query(func.count(AppDatasetJoin.id)).filter(AppDatasetJoin.dataset_id == self.id,
App.id == AppDatasetJoin.app_id).scalar()
@property
def document_count(self):
return db.session.query(func.count(Document.id)).filter(Document.dataset_id == self.id).scalar()
@property
def available_document_count(self):
return db.session.query(func.count(Document.id)).filter(
Document.dataset_id == self.id,
Document.indexing_status == 'completed',
Document.enabled == True,
Document.archived == False
).scalar()
@property
def available_segment_count(self):
return db.session.query(func.count(DocumentSegment.id)).filter(
DocumentSegment.dataset_id == self.id,
DocumentSegment.status == 'completed',
DocumentSegment.enabled == True
).scalar()
@property
def word_count(self):
return Document.query.with_entities(func.coalesce(func.sum(Document.word_count))) \
.filter(Document.dataset_id == self.id).scalar()
@property
def doc_form(self):
document = db.session.query(Document).filter(
Document.dataset_id == self.id).first()
if document:
return document.doc_form
return None
@property
def retrieval_model_dict(self):
default_retrieval_model = {
'search_method': RetrievalMethod.SEMANTIC_SEARCH.value,
'reranking_enable': False,
'reranking_model': {
'reranking_provider_name': '',
'reranking_model_name': ''
},
'top_k': 2,
'score_threshold_enabled': False
}
return self.retrieval_model if self.retrieval_model else default_retrieval_model
@property
def tags(self):
tags = db.session.query(Tag).join(
TagBinding,
Tag.id == TagBinding.tag_id
).filter(
TagBinding.target_id == self.id,
TagBinding.tenant_id == self.tenant_id,
Tag.tenant_id == self.tenant_id,
Tag.type == 'knowledge'
).all()
return tags if tags else []
@staticmethod
def gen_collection_name_by_id(dataset_id: str) -> str:
normalized_dataset_id = dataset_id.replace("-", "_")
return f'Vector_index_{normalized_dataset_id}_Node'
class DatasetProcessRule(db.Model):
__tablename__ = 'dataset_process_rules'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='dataset_process_rule_pkey'),
db.Index('dataset_process_rule_dataset_id_idx', 'dataset_id'),
)
id = db.Column(StringUUID, nullable=False,
server_default=db.text('uuid_generate_v4()'))
dataset_id = db.Column(StringUUID, nullable=False)
mode = db.Column(db.String(255), nullable=False,
server_default=db.text("'automatic'::character varying"))
rules = db.Column(db.Text, nullable=True)
created_by = db.Column(StringUUID, nullable=False)
created_at = db.Column(db.DateTime, nullable=False,
server_default=db.text('CURRENT_TIMESTAMP(0)'))
MODES = ['automatic', 'custom']
PRE_PROCESSING_RULES = ['remove_stopwords', 'remove_extra_spaces', 'remove_urls_emails']
AUTOMATIC_RULES = {
'pre_processing_rules': [
{'id': 'remove_extra_spaces', 'enabled': True},
{'id': 'remove_urls_emails', 'enabled': False}
],
'segmentation': {
'delimiter': '\n',
'max_tokens': 500,
'chunk_overlap': 50
}
}
def to_dict(self):
return {
'id': self.id,
'dataset_id': self.dataset_id,
'mode': self.mode,
'rules': self.rules_dict,
'created_by': self.created_by,
'created_at': self.created_at,
}
@property
def rules_dict(self):
try:
return json.loads(self.rules) if self.rules else None
except JSONDecodeError:
return None
class Document(db.Model):
__tablename__ = 'documents'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='document_pkey'),
db.Index('document_dataset_id_idx', 'dataset_id'),
db.Index('document_is_paused_idx', 'is_paused'),
db.Index('document_tenant_idx', 'tenant_id'),
)
# initial fields
id = db.Column(StringUUID, nullable=False,
server_default=db.text('uuid_generate_v4()'))
tenant_id = db.Column(StringUUID, nullable=False)
dataset_id = db.Column(StringUUID, nullable=False)
position = db.Column(db.Integer, nullable=False)
data_source_type = db.Column(db.String(255), nullable=False)
data_source_info = db.Column(db.Text, nullable=True)
dataset_process_rule_id = db.Column(StringUUID, nullable=True)
batch = db.Column(db.String(255), nullable=False)
name = db.Column(db.String(255), nullable=False)
created_from = db.Column(db.String(255), nullable=False)
created_by = db.Column(StringUUID, nullable=False)
created_api_request_id = db.Column(StringUUID, nullable=True)
created_at = db.Column(db.DateTime, nullable=False,
server_default=db.text('CURRENT_TIMESTAMP(0)'))
# start processing
processing_started_at = db.Column(db.DateTime, nullable=True)
# parsing
file_id = db.Column(db.Text, nullable=True)
word_count = db.Column(db.Integer, nullable=True)
parsing_completed_at = db.Column(db.DateTime, nullable=True)
# cleaning
cleaning_completed_at = db.Column(db.DateTime, nullable=True)
# split
splitting_completed_at = db.Column(db.DateTime, nullable=True)
# indexing
tokens = db.Column(db.Integer, nullable=True)
indexing_latency = db.Column(db.Float, nullable=True)
completed_at = db.Column(db.DateTime, nullable=True)
# pause
is_paused = db.Column(db.Boolean, nullable=True, server_default=db.text('false'))
paused_by = db.Column(StringUUID, nullable=True)
paused_at = db.Column(db.DateTime, nullable=True)
# error
error = db.Column(db.Text, nullable=True)
stopped_at = db.Column(db.DateTime, nullable=True)
# basic fields
indexing_status = db.Column(db.String(
255), nullable=False, server_default=db.text("'waiting'::character varying"))
enabled = db.Column(db.Boolean, nullable=False,
server_default=db.text('true'))
disabled_at = db.Column(db.DateTime, nullable=True)
disabled_by = db.Column(StringUUID, nullable=True)
archived = db.Column(db.Boolean, nullable=False,
server_default=db.text('false'))
archived_reason = db.Column(db.String(255), nullable=True)
archived_by = db.Column(StringUUID, nullable=True)
archived_at = db.Column(db.DateTime, nullable=True)
updated_at = db.Column(db.DateTime, nullable=False,
server_default=db.text('CURRENT_TIMESTAMP(0)'))
doc_type = db.Column(db.String(40), nullable=True)
doc_metadata = db.Column(db.JSON, nullable=True)
doc_form = db.Column(db.String(
255), nullable=False, server_default=db.text("'text_model'::character varying"))
doc_language = db.Column(db.String(255), nullable=True)
DATA_SOURCES = ['upload_file', 'notion_import', 'website_crawl']
@property
def display_status(self):
status = None
if self.indexing_status == 'waiting':
status = 'queuing'
elif self.indexing_status not in ['completed', 'error', 'waiting'] and self.is_paused:
status = 'paused'
elif self.indexing_status in ['parsing', 'cleaning', 'splitting', 'indexing']:
status = 'indexing'
elif self.indexing_status == 'error':
status = 'error'
elif self.indexing_status == 'completed' and not self.archived and self.enabled:
status = 'available'
elif self.indexing_status == 'completed' and not self.archived and not self.enabled:
status = 'disabled'
elif self.indexing_status == 'completed' and self.archived:
status = 'archived'
return status
@property
def data_source_info_dict(self):
if self.data_source_info:
try:
data_source_info_dict = json.loads(self.data_source_info)
except JSONDecodeError:
data_source_info_dict = {}
return data_source_info_dict
return None
@property
def data_source_detail_dict(self):
if self.data_source_info:
if self.data_source_type == 'upload_file':
data_source_info_dict = json.loads(self.data_source_info)
file_detail = db.session.query(UploadFile). \
filter(UploadFile.id == data_source_info_dict['upload_file_id']). \
one_or_none()
if file_detail:
return {
'upload_file': {
'id': file_detail.id,
'name': file_detail.name,
'size': file_detail.size,
'extension': file_detail.extension,
'mime_type': file_detail.mime_type,
'created_by': file_detail.created_by,
'created_at': file_detail.created_at.timestamp()
}
}
elif self.data_source_type == 'notion_import' or self.data_source_type == 'website_crawl':
return json.loads(self.data_source_info)
return {}
@property
def average_segment_length(self):
if self.word_count and self.word_count != 0 and self.segment_count and self.segment_count != 0:
return self.word_count // self.segment_count
return 0
@property
def dataset_process_rule(self):
if self.dataset_process_rule_id:
return db.session.get(DatasetProcessRule, self.dataset_process_rule_id)
return None
@property
def dataset(self):
return db.session.query(Dataset).filter(Dataset.id == self.dataset_id).one_or_none()
@property
def segment_count(self):
return DocumentSegment.query.filter(DocumentSegment.document_id == self.id).count()
@property
def hit_count(self):
return DocumentSegment.query.with_entities(func.coalesce(func.sum(DocumentSegment.hit_count))) \
.filter(DocumentSegment.document_id == self.id).scalar()
def to_dict(self):
return {
'id': self.id,
'tenant_id': self.tenant_id,
'dataset_id': self.dataset_id,
'position': self.position,
'data_source_type': self.data_source_type,
'data_source_info': self.data_source_info,
'dataset_process_rule_id': self.dataset_process_rule_id,
'batch': self.batch,
'name': self.name,
'created_from': self.created_from,
'created_by': self.created_by,
'created_api_request_id': self.created_api_request_id,
'created_at': self.created_at,
'processing_started_at': self.processing_started_at,
'file_id': self.file_id,
'word_count': self.word_count,
'parsing_completed_at': self.parsing_completed_at,
'cleaning_completed_at': self.cleaning_completed_at,
'splitting_completed_at': self.splitting_completed_at,
'tokens': self.tokens,
'indexing_latency': self.indexing_latency,
'completed_at': self.completed_at,
'is_paused': self.is_paused,
'paused_by': self.paused_by,
'paused_at': self.paused_at,
'error': self.error,
'stopped_at': self.stopped_at,
'indexing_status': self.indexing_status,
'enabled': self.enabled,
'disabled_at': self.disabled_at,
'disabled_by': self.disabled_by,
'archived': self.archived,
'archived_reason': self.archived_reason,
'archived_by': self.archived_by,
'archived_at': self.archived_at,
'updated_at': self.updated_at,
'doc_type': self.doc_type,
'doc_metadata': self.doc_metadata,
'doc_form': self.doc_form,
'doc_language': self.doc_language,
'display_status': self.display_status,
'data_source_info_dict': self.data_source_info_dict,
'average_segment_length': self.average_segment_length,
'dataset_process_rule': self.dataset_process_rule.to_dict() if self.dataset_process_rule else None,
'dataset': self.dataset.to_dict() if self.dataset else None,
'segment_count': self.segment_count,
'hit_count': self.hit_count
}
@classmethod
def from_dict(cls, data: dict):
return cls(
id=data.get('id'),
tenant_id=data.get('tenant_id'),
dataset_id=data.get('dataset_id'),
position=data.get('position'),
data_source_type=data.get('data_source_type'),
data_source_info=data.get('data_source_info'),
dataset_process_rule_id=data.get('dataset_process_rule_id'),
batch=data.get('batch'),
name=data.get('name'),
created_from=data.get('created_from'),
created_by=data.get('created_by'),
created_api_request_id=data.get('created_api_request_id'),
created_at=data.get('created_at'),
processing_started_at=data.get('processing_started_at'),
file_id=data.get('file_id'),
word_count=data.get('word_count'),
parsing_completed_at=data.get('parsing_completed_at'),
cleaning_completed_at=data.get('cleaning_completed_at'),
splitting_completed_at=data.get('splitting_completed_at'),
tokens=data.get('tokens'),
indexing_latency=data.get('indexing_latency'),
completed_at=data.get('completed_at'),
is_paused=data.get('is_paused'),
paused_by=data.get('paused_by'),
paused_at=data.get('paused_at'),
error=data.get('error'),
stopped_at=data.get('stopped_at'),
indexing_status=data.get('indexing_status'),
enabled=data.get('enabled'),
disabled_at=data.get('disabled_at'),
disabled_by=data.get('disabled_by'),
archived=data.get('archived'),
archived_reason=data.get('archived_reason'),
archived_by=data.get('archived_by'),
archived_at=data.get('archived_at'),
updated_at=data.get('updated_at'),
doc_type=data.get('doc_type'),
doc_metadata=data.get('doc_metadata'),
doc_form=data.get('doc_form'),
doc_language=data.get('doc_language')
)
class DocumentSegment(db.Model):
__tablename__ = 'document_segments'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='document_segment_pkey'),
db.Index('document_segment_dataset_id_idx', 'dataset_id'),
db.Index('document_segment_document_id_idx', 'document_id'),
db.Index('document_segment_tenant_dataset_idx', 'dataset_id', 'tenant_id'),
db.Index('document_segment_tenant_document_idx', 'document_id', 'tenant_id'),
db.Index('document_segment_dataset_node_idx', 'dataset_id', 'index_node_id'),
db.Index('document_segment_tenant_idx', 'tenant_id'),
)
# initial fields
id = db.Column(StringUUID, nullable=False,
server_default=db.text('uuid_generate_v4()'))
tenant_id = db.Column(StringUUID, nullable=False)
dataset_id = db.Column(StringUUID, nullable=False)
document_id = db.Column(StringUUID, nullable=False)
position = db.Column(db.Integer, nullable=False)
content = db.Column(db.Text, nullable=False)
answer = db.Column(db.Text, nullable=True)
word_count = db.Column(db.Integer, nullable=False)
tokens = db.Column(db.Integer, nullable=False)
# indexing fields
keywords = db.Column(db.JSON, nullable=True)
index_node_id = db.Column(db.String(255), nullable=True)
index_node_hash = db.Column(db.String(255), nullable=True)
# basic fields
hit_count = db.Column(db.Integer, nullable=False, default=0)
enabled = db.Column(db.Boolean, nullable=False,
server_default=db.text('true'))
disabled_at = db.Column(db.DateTime, nullable=True)
disabled_by = db.Column(StringUUID, nullable=True)
status = db.Column(db.String(255), nullable=False,
server_default=db.text("'waiting'::character varying"))
created_by = db.Column(StringUUID, nullable=False)
created_at = db.Column(db.DateTime, nullable=False,
server_default=db.text('CURRENT_TIMESTAMP(0)'))
updated_by = db.Column(StringUUID, nullable=True)
updated_at = db.Column(db.DateTime, nullable=False,
server_default=db.text('CURRENT_TIMESTAMP(0)'))
indexing_at = db.Column(db.DateTime, nullable=True)
completed_at = db.Column(db.DateTime, nullable=True)
error = db.Column(db.Text, nullable=True)
stopped_at = db.Column(db.DateTime, nullable=True)
@property
def dataset(self):
return db.session.query(Dataset).filter(Dataset.id == self.dataset_id).first()
@property
def document(self):
return db.session.query(Document).filter(Document.id == self.document_id).first()
@property
def previous_segment(self):
return db.session.query(DocumentSegment).filter(
DocumentSegment.document_id == self.document_id,
DocumentSegment.position == self.position - 1
).first()
@property
def next_segment(self):
return db.session.query(DocumentSegment).filter(
DocumentSegment.document_id == self.document_id,
DocumentSegment.position == self.position + 1
).first()
def get_sign_content(self):
pattern = r"/files/([a-f0-9\-]+)/image-preview"
text = self.content
matches = re.finditer(pattern, text)
signed_urls = []
for match in matches:
upload_file_id = match.group(1)
nonce = os.urandom(16).hex()
timestamp = str(int(time.time()))
data_to_sign = f"image-preview|{upload_file_id}|{timestamp}|{nonce}"
secret_key = dify_config.SECRET_KEY.encode() if dify_config.SECRET_KEY else b''
sign = hmac.new(secret_key, data_to_sign.encode(), hashlib.sha256).digest()
encoded_sign = base64.urlsafe_b64encode(sign).decode()
params = f"timestamp={timestamp}&nonce={nonce}&sign={encoded_sign}"
signed_url = f"{match.group(0)}?{params}"
signed_urls.append((match.start(), match.end(), signed_url))
# Reconstruct the text with signed URLs
offset = 0
for start, end, signed_url in signed_urls:
text = text[:start + offset] + signed_url + text[end + offset:]
offset += len(signed_url) - (end - start)
return text
class AppDatasetJoin(db.Model):
__tablename__ = 'app_dataset_joins'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='app_dataset_join_pkey'),
db.Index('app_dataset_join_app_dataset_idx', 'dataset_id', 'app_id'),
)
id = db.Column(StringUUID, primary_key=True, nullable=False, server_default=db.text('uuid_generate_v4()'))
app_id = db.Column(StringUUID, nullable=False)
dataset_id = db.Column(StringUUID, nullable=False)
created_at = db.Column(db.DateTime, nullable=False, server_default=db.func.current_timestamp())
@property
def app(self):
return db.session.get(App, self.app_id)
class DatasetQuery(db.Model):
__tablename__ = 'dataset_queries'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='dataset_query_pkey'),
db.Index('dataset_query_dataset_id_idx', 'dataset_id'),
)
id = db.Column(StringUUID, primary_key=True, nullable=False, server_default=db.text('uuid_generate_v4()'))
dataset_id = db.Column(StringUUID, nullable=False)
content = db.Column(db.Text, nullable=False)
source = db.Column(db.String(255), nullable=False)
source_app_id = db.Column(StringUUID, nullable=True)
created_by_role = db.Column(db.String, nullable=False)
created_by = db.Column(StringUUID, nullable=False)
created_at = db.Column(db.DateTime, nullable=False, server_default=db.func.current_timestamp())
class DatasetKeywordTable(db.Model):
__tablename__ = 'dataset_keyword_tables'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='dataset_keyword_table_pkey'),
db.Index('dataset_keyword_table_dataset_id_idx', 'dataset_id'),
)
id = db.Column(StringUUID, primary_key=True, server_default=db.text('uuid_generate_v4()'))
dataset_id = db.Column(StringUUID, nullable=False, unique=True)
keyword_table = db.Column(db.Text, nullable=False)
data_source_type = db.Column(db.String(255), nullable=False,
server_default=db.text("'database'::character varying"))
@property
def keyword_table_dict(self):
class SetDecoder(json.JSONDecoder):
def __init__(self, *args, **kwargs):
super().__init__(object_hook=self.object_hook, *args, **kwargs)
def object_hook(self, dct):
if isinstance(dct, dict):
for keyword, node_idxs in dct.items():
if isinstance(node_idxs, list):
dct[keyword] = set(node_idxs)
return dct
# get dataset
dataset = Dataset.query.filter_by(
id=self.dataset_id
).first()
if not dataset:
return None
if self.data_source_type == 'database':
return json.loads(self.keyword_table, cls=SetDecoder) if self.keyword_table else None
else:
file_key = 'keyword_files/' + dataset.tenant_id + '/' + self.dataset_id + '.txt'
try:
keyword_table_text = storage.load_once(file_key)
if keyword_table_text:
return json.loads(keyword_table_text.decode('utf-8'), cls=SetDecoder)
return None
except Exception as e:
logging.exception(str(e))
return None
class Embedding(db.Model):
__tablename__ = 'embeddings'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='embedding_pkey'),
db.UniqueConstraint('model_name', 'hash', 'provider_name', name='embedding_hash_idx')
)
id = db.Column(StringUUID, primary_key=True, server_default=db.text('uuid_generate_v4()'))
model_name = db.Column(db.String(40), nullable=False,
server_default=db.text("'text-embedding-ada-002'::character varying"))
hash = db.Column(db.String(64), nullable=False)
embedding = db.Column(db.LargeBinary, nullable=False)
created_at = db.Column(db.DateTime, nullable=False, server_default=db.text('CURRENT_TIMESTAMP(0)'))
provider_name = db.Column(db.String(40), nullable=False,
server_default=db.text("''::character varying"))
def set_embedding(self, embedding_data: list[float]):
self.embedding = pickle.dumps(embedding_data, protocol=pickle.HIGHEST_PROTOCOL)
def get_embedding(self) -> list[float]:
return pickle.loads(self.embedding)
class DatasetCollectionBinding(db.Model):
__tablename__ = 'dataset_collection_bindings'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='dataset_collection_bindings_pkey'),
db.Index('provider_model_name_idx', 'provider_name', 'model_name')
)
id = db.Column(StringUUID, primary_key=True, server_default=db.text('uuid_generate_v4()'))
provider_name = db.Column(db.String(40), nullable=False)
model_name = db.Column(db.String(40), nullable=False)
type = db.Column(db.String(40), server_default=db.text("'dataset'::character varying"), nullable=False)
collection_name = db.Column(db.String(64), nullable=False)
created_at = db.Column(db.DateTime, nullable=False, server_default=db.text('CURRENT_TIMESTAMP(0)'))
class DatasetPermission(db.Model):
__tablename__ = 'dataset_permissions'
__table_args__ = (
db.PrimaryKeyConstraint('id', name='dataset_permission_pkey'),
db.Index('idx_dataset_permissions_dataset_id', 'dataset_id'),
db.Index('idx_dataset_permissions_account_id', 'account_id'),
db.Index('idx_dataset_permissions_tenant_id', 'tenant_id')
)
id = db.Column(StringUUID, server_default=db.text('uuid_generate_v4()'), primary_key=True)
dataset_id = db.Column(StringUUID, nullable=False)
account_id = db.Column(StringUUID, nullable=False)
tenant_id = db.Column(StringUUID, nullable=False)
has_permission = db.Column(db.Boolean, nullable=False, server_default=db.text('true'))
created_at = db.Column(db.DateTime, nullable=False, server_default=db.text('CURRENT_TIMESTAMP(0)'))