Entity D 语言的 ORM 框架 项目简介
Entity 是 D 语言(dlang)数据库操作 ORM 框架,设计参照 javax JPA 实现,具有很好的扩展性和规范性,数据库驱动依赖 Huntlabs 开发的 database for dlang 。特性实现了完整的 CriteriaQuery 支持对 Repository 也有部分封装完全对象化查询,不用考虑底层数据库驱动支持的数据库PostgreSQL 9.0+MySQL 5.1+SQLite 3.7.11+使用示例import entity;
@Table("user")
class User : Entity
{
@PrimaryKey
@AutoIncrement
int id;
string name;
double money;
string email;
bool status;
}
void main()
{
DatabaseOption options = new DatabaseOption("mysql://root:123456@localhost:3306/huntblog?charset=utf-8");
EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("default", options);
EntityManager em = entityManagerFactory.createEntityManager();
// begin transaction
em.getTransaction().begin();
// define your database existing row id in here
int id = 10;
auto user = em.find!User(id);
log("User name is: ", user.name);
// commit transaction
em.getTransaction().commit();
em.close();
entityManagerFactory.close();
}Insert rowauto user = new User();
user.name = "Brian";
user.email = "[email protected]";
user.money = 99.9;
// insert user
em.persist(user);
log("User id is: ", user.id);Delete rowint n = em.remove!User(id);
log("The number of users deleted is: ", n);Update rowauto user = em.find!User(id);
log("User name is: ", user.name);
user.name = "zoujiaqing";
em.merge!User(user);
log("The number of users updated is: ", n);Use CriteriaQuery to find// create CriteriaBuilder object from em
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery!User criteriaQuery = builder.createQuery!User;
Root!User root = criteriaQuery.from();
Predicate p1 = builder.equal(root.User.id, id);
TypedQuery!User typedQuery = em.createQuery(criteriaQuery.select(root).where(p1));
auto user = typedQuery.getSingleResult();
log("User name is: ", user.name);Use CriteriaQuery to Multi-condition find// create CriteriaBuilder object from em
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery!User criteriaQuery = builder.createQuery!User;
Root!User root = criteriaQuery.from();
Predicate p1 = builder.lt(root.User.id, 1000); // User id is less than 1000.
Predicate p2 = builder.gt(root.User.money, 0); // User money is greater than 0.
Predicate p3 = builder.like(root.User.name, "z%"); // User name prefix is z.
TypedQuery!User typedQuery = em.createQuery(criteriaQuery.select(root).where(builder.and(p1, p2), p3));
User[] users = typedQuery.getResultList();
log("The number of users found is: ", users.length);
@Table("user")
class User : Entity
{
@PrimaryKey
@AutoIncrement
int id;
string name;
double money;
string email;
bool status;
}
void main()
{
DatabaseOption options = new DatabaseOption("mysql://root:123456@localhost:3306/huntblog?charset=utf-8");
EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("default", options);
EntityManager em = entityManagerFactory.createEntityManager();
// begin transaction
em.getTransaction().begin();
// define your database existing row id in here
int id = 10;
auto user = em.find!User(id);
log("User name is: ", user.name);
// commit transaction
em.getTransaction().commit();
em.close();
entityManagerFactory.close();
}Insert rowauto user = new User();
user.name = "Brian";
user.email = "[email protected]";
user.money = 99.9;
// insert user
em.persist(user);
log("User id is: ", user.id);Delete rowint n = em.remove!User(id);
log("The number of users deleted is: ", n);Update rowauto user = em.find!User(id);
log("User name is: ", user.name);
user.name = "zoujiaqing";
em.merge!User(user);
log("The number of users updated is: ", n);Use CriteriaQuery to find// create CriteriaBuilder object from em
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery!User criteriaQuery = builder.createQuery!User;
Root!User root = criteriaQuery.from();
Predicate p1 = builder.equal(root.User.id, id);
TypedQuery!User typedQuery = em.createQuery(criteriaQuery.select(root).where(p1));
auto user = typedQuery.getSingleResult();
log("User name is: ", user.name);Use CriteriaQuery to Multi-condition find// create CriteriaBuilder object from em
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery!User criteriaQuery = builder.createQuery!User;
Root!User root = criteriaQuery.from();
Predicate p1 = builder.lt(root.User.id, 1000); // User id is less than 1000.
Predicate p2 = builder.gt(root.User.money, 0); // User money is greater than 0.
Predicate p3 = builder.like(root.User.name, "z%"); // User name prefix is z.
TypedQuery!User typedQuery = em.createQuery(criteriaQuery.select(root).where(builder.and(p1, p2), p3));
User[] users = typedQuery.getResultList();
log("The number of users found is: ", users.length);