my model definitions for both Employee and Leaves Applied table are given below two tables are :
# Class for creating employee table
class Employee(Base):
__tablename__ = "employee"
id = Column(Integer, primary_key=True, nullable=False)
name = Column(String(30), nullable=False)
designation = Column(Integer,
ForeignKey("designation.id",
use_alter=True,
name="fk_designation",
onupdate="CASCADE",
ondelete="RESTRICT"))
team = Column(Integer, ForeignKey("team.id",
use_alter=True,
name="fk_team",
onupdate="CASCADE",
ondelete="RESTRICT"))
workstation_id = Column(String(30), nullable=False)
phone_extension = Column(String(30), nullable=False)
leave_eligibility_id = Column(Integer,
ForeignKey("leaves_eligibility.id",
use_alter=True,
name="fk_leave_eligibility",
onupdate="CASCADE",
ondelete="RESTRICT"))
manager_id = Column(Integer, ForeignKey("employee.id",
use_alter=True,
name="fk_manager_id",
onupdate="CASCADE",
ondelete="RESTRICT"))
leave_approver_id = Column(Integer,
ForeignKey("employee.id",
use_alter=True,
name="fk_leaveapprover_id",
onupdate="CASCADE",
ondelete="RESTRICT"))
leave_recommender_id = Column(Integer,
ForeignKey("employee.id",
use_alter=True,
name="fk_leaverecommender_id",
onupdate="CASCADE",
ondelete="RESTRICT"))
def __init__(self, name, designation,team,workstation_id, phone_extension,leave_eligibility_id,manager_id,leave_approver_id,leave_recommender_id):
self.name = name
self.designation = designation
self.team = team
self.workstation_id = workstation_id
self.phone_extension = phone_extension
self.leave_eligibility_id = leave_eligibility_id
self.manager_id = manager_id
self.leave_approver_id = leave_approver_id
self.leave_recommender_id = leave_recommender_id
# Class for creating team table
class LeavesApplied(Base):
__tablename__ = "leaves_applied"
id = Column(Integer, primary_key=True, nullable=False)
employee_id = Column(Integer,
ForeignKey("employee.id",
use_alter=True,
name="fk_emp_id",
onupdate="CASCADE",
ondelete="RESTRICT"))
from_date = Column(Date, nullable=False)
to_date = Column(Date, nullable=False)
half_day = Column(TINYINT(1))
type_id = Column("type_id",
mysql.ENUM("CASUAL_LEAVE",
"SICK_LEAVE",
"PRIVILEGED_LEAVE",
"ON_DUTY",
"AUTHORISED_LOSS_OF_PAY"))
decided_by_id = Column(Integer,
ForeignKey("employee.id",
use_alter=True,
name="fk_decided_by_id",
onupdate="CASCADE",
ondelete="RESTRICT"))
reason = Column(TEXT)
status = Column("status",
mysql.ENUM("RECOMMENDED",
"DECLINED",
"APPROVED",
"PENDING"))
recommended_by_id = Column(Integer,
ForeignKey("employee.id",
use_alter=True,
name="fk_recommended_by_id",
onupdate="CASCADE",
ondelete="RESTRICT"))
children=relationship("Employee",
backref=backref('parent',remote_side=[employee_id]),
foreign_keys='LeavesApplied.employee_id',
# Children will be represented as a dictionary
# On the attribute of manager_id
collection_class=attribute_mapped_collection(
'id'),)
def __init__(self,employee_id,from_date,to_date,half_day,type_id,decided_by_id,reason,status,rec ommended_by_id):
self.employee_id=employee_id
self.from_date = from_date
self.to_date = to_date
self.half_day = half_day
self.type_id = type_id
self.decided_by_id=decided_by_id
self.reason = reason
self.status = status
self.recommended_by_id=recommended_by_id
am executing the below query
rows=self.db.query(LeavesApplied,Employee)
.join(Employee)
.filter(LeavesApplied.employee_id== Employee.id)
.filter(Employee.id==1255).all()
but its throwing an error
InvalidRequestError: Could not find a FROM clause to join from.
Tried joining to , but got: Can't determine join between'leaves_applied' and 'employee'; tables have more than one foreign key constraint relationship between them. Please specify the 'onclause' of this join explicitly.