How to combine and match 2 tables in Flask - flask

Question

The id is associated with the postID. How can I get the contact information and comment information of that id when I enter the id(/postComments/id)?
I'm getting an internal error...
class posts(db.Model):
__tablename__ = "posts"
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(100))
postName = db.Column(db.String(100))
postDescription = db.Column(db.String(500))
postLike = db.Column(db.Integer)
class postComment(db.Model):
__tablename__ = "postComment"
id = db.Column(db.Integer, primary_key=True)
postID = db.Column(db.Integer)
senderName = db.Column(db.String(20))
commentPost = db.Column(db.String(300))
#app.route('/postComments/<id>',methods=['GET'])
def get_comment_post(id):
userList = posts.query\
.join(postComment, posts.id == postComment.postID)\
.add_columns(posts.id, posts.name, posts.postDescription, postComment.commentPost, postComment.senderName)\
.filter(posts.id == id)

Answer 1

Modify your models (and perform migrations) to allow reference for foreign keys:
class postComment(db.Model):
__tablename__ = "postComment"
id = db.Column(db.Integer, primary_key=True)
postID = db.Column(db.Integer, db.ForeignKey("posts.id")) # <--- Set to Foreign Key
senderName = db.Column(db.String(20))
commentPost = db.Column(db.String(300))
# Establish relationship
post = db.Relationship("posts", backref="postComment") # <--- backref makes this relationship available in the other class
# This should get simpler...
#app.route('/postComments/<id>',methods=['GET'])
def get_comment_post(id):
# Get the comment based on id
my_comment = postComment.query.get(id)
# Get the post associated with that comment
my_post = my_comment.post
# It looks like you're doing an intricate data transformation.
# Do that here...
# Also, for debugging, consider using the following print statements
print(my_comment.__dict__)
print(my_post.__dict__)
Consider reading this slightly more detailed explanation for establishing relationships.