models.py

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, nullable=False)
    password_hash = db.Column(db.String(128), nullable=False)
    searches = db.relationship('SearchHistory', backref='user', lazy=True)

class SearchHistory(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    query = db.Column(db.String(512), nullable=False)
    filters = db.Column(db.String(256), nullable=True)
    timestamp = db.Column(db.DateTime, nullable=False)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=False)