orm

问题 I have two models. User and Manager User Model const UserMaster = sequelize.define('User', { UserId: { type: DataTypes.BIGINT, allowNull: false, primaryKey: true, autoIncrement: true }, RelationshipId: { type: DataTypes.STRING, allowNull: true, foreignKey: true }, UserName: { type: DataTypes.STRING, allowNull: true } }) Manager model const Manager = sequelize.define('Manager', { ManagerId: { type: DataTypes.BIGINT, allowNull: false, primaryKey: true, autoIncrement: true }, RelationshipId: {

问题 I am developing web applications, APIs, and backends using the Django MVC framework. A major aspect of Django is its implementation of an ORM for models. It is an exceptionally good ORM. Typically when using Django, one utilizes an existing interface that maps one's Django model to a specific DBMS like Postgres, MySQL, or Oracle for example. I have some specific needs, requirements regarding performance and scalability, so I really want to use AWS's Dynamo DB because it is highly cost

问题 I am developing web applications, APIs, and backends using the Django MVC framework. A major aspect of Django is its implementation of an ORM for models. It is an exceptionally good ORM. Typically when using Django, one utilizes an existing interface that maps one's Django model to a specific DBMS like Postgres, MySQL, or Oracle for example. I have some specific needs, requirements regarding performance and scalability, so I really want to use AWS's Dynamo DB because it is highly cost

问题 I have following model in django Business ID Business Name Business Revenue Date Here is the sample data: Business ID | Business Name | Business Revenue | Date 1 B1 1000 2012-10-13 2 B2 20000 2013-10-16 1 B1 2000 2013-04-13 2 B2 24000 2014-09-02 I want to fetch all businesses having latest date. Here is the output I want: Business ID | Business Name | Business Revenue | Date 1 B1 2000 2013-04-13 2 B2 24000 2014-09-02 I have tried this: model.objects.filter(date__gte = date.today()).order_by(

问题 I have following model in django Business ID Business Name Business Revenue Date Here is the sample data: Business ID | Business Name | Business Revenue | Date 1 B1 1000 2012-10-13 2 B2 20000 2013-10-16 1 B1 2000 2013-04-13 2 B2 24000 2014-09-02 I want to fetch all businesses having latest date. Here is the output I want: Business ID | Business Name | Business Revenue | Date 1 B1 2000 2013-04-13 2 B2 24000 2014-09-02 I have tried this: model.objects.filter(date__gte = date.today()).order_by(

问题 I have following model in django Business ID Business Name Business Revenue Date Here is the sample data: Business ID | Business Name | Business Revenue | Date 1 B1 1000 2012-10-13 2 B2 20000 2013-10-16 1 B1 2000 2013-04-13 2 B2 24000 2014-09-02 I want to fetch all businesses having latest date. Here is the output I want: Business ID | Business Name | Business Revenue | Date 1 B1 2000 2013-04-13 2 B2 24000 2014-09-02 I have tried this: model.objects.filter(date__gte = date.today()).order_by(

问题 I am getting a very strange problem with sequelize, When I try to call the function findAll it works fine (same for create and destroy), but when I try to call function "findById", it throws "findById is not a function" (same for "FindOne"). //works fine var gammes = models.gamme.findAll().then(function(gammes) { res.render('admin/gammes/gestion_gamme',{ layout: 'admin/layouts/structure' , gammes : gammes, js: "gammes" }); }); // throws models.gamme.findById is not a function models.gamme

问题 How to work with Django models inside Airflow tasks? According to official Airflow documentation, Airflow provides hooks for interaction with databases (like MySqlHook / PostgresHook / etc) that can be later used in Operators for row query execution. Attaching the core code fragments: Copy from https://airflow.apache.org/_modules/mysql_hook.html class MySqlHook(DbApiHook): conn_name_attr = 'mysql_conn_id' default_conn_name = 'mysql_default' supports_autocommit = True def get_conn(self): """

问题 How to work with Django models inside Airflow tasks? According to official Airflow documentation, Airflow provides hooks for interaction with databases (like MySqlHook / PostgresHook / etc) that can be later used in Operators for row query execution. Attaching the core code fragments: Copy from https://airflow.apache.org/_modules/mysql_hook.html class MySqlHook(DbApiHook): conn_name_attr = 'mysql_conn_id' default_conn_name = 'mysql_default' supports_autocommit = True def get_conn(self): """

问题 From the SQLAlchemy ORM Tutorial: You can control the names using the label() construct for scalar attributes and aliased for class constructs: >>> from sqlalchemy.orm import aliased >>> user_alias = aliased(User, name='user_alias') >>> for row in session.query(user_alias, user_alias.name.label('name_label')).all(): ... print row.user_alias, row.name_label This seems to be a lot more typing and a lot less readable than the plain class-instrumented descriptors: >>> for row in session.query