How to add new dict to list of dict with SQLAlchemy

Question

Let's say this is a sample json.

{
  "id": 1,
  "details": [
    {
      "a": "100",
    }
  ]
}

The result that i want is add {'b': '200'} to details and it will look like this.

{
  "id": 1,
  "details": [
    {
      "a": "100",
    },
    {
      "b": "200",
    },
  ]
}

In my file, I have tried many times but it still doesn't work So, how to add dict with sqlalchemy

class Models(Base):
    __tablename__ = 'Table'
    id = Column(Integer, primary_key=True)
    details = Column(JSONB, nullable=False, server_default='[]')


@router.post("/post2")
async def post2(id: int = 1):
    session = Session()
    user = session.query(Models).filter(
        Models.id == id).first()
    for var in user.details:
        var.append({"b": "200"})
    session.commit()
    return user

Answer 1

You probably need to use flag_modified , becuase you cannot update JSONB directly:

from sqlalchemy.orm.attributes import flag_modified

@router.post("/post2")
async def post2(id: int = 1):
    session = Session()
    user = session.query(Models).filter(
        Models.id == id
    ).first()
    
    user.details.append({"b": "200"})
    flag_modified(user, "details")    
    session.commit()
    return user

or rewrite whole collection:

import copy

@router.post("/post2")
async def post2(id: int = 1):
    session = Session()
    user = session.query(Models).filter(
        Models.id == id
    ).first()
    
    details = copy.deepcopy(user.details)
    details.append({"b": "200"})
    user.details = details   
    session.commit()
    return user

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