JAVA下唯一一款搞定OLTP+OLAP的强类型查询这就是最好用的ORM相见恨晚

介绍

首先非常感谢 FreeSQL 提供的部分源码,让我借鉴了不少功能点,整体设计并没有参考FreeSQL(因为java压根没有expression所以没办法参考)只是在数据库方言上FreeSQL提供的SQL让我少走了很多弯路,所以才让easy-query可以走的这么迅速

丑话说在前头,这是java下面唯一一款可以完全替代SQL的强类型ORM,完美支持OLTP和OLAP语法筛选记住是唯一一款

想体验完整版请查看文档博客篇幅有限见谅本次仅展示OLTP的对象关联查询

easy-query

文档地址 https://xuejmnet.github.io/easy-query-doc/ (为什么没有gitee的文档因为gitee pages挂掉了目前没办法更新)

GITHUB地址 https://github.com/xuejmnet/easy-query

GITEE地址 https://gitee.com/xuejm/easy-query

java下面唯一一款支持强类型OLTP和OLAP语法并且支持分表分库的最好用的ORM,为什么是最好用的OLTP那么我们先来看一个简单的例子

• 用户、角色、菜单典型的多对多关联关系(隐式子查询)
• 其中用户和用户所在地址为一对一关系(隐式join)

  @Table("t_user") @Data @EntityProxy public class SysUser implements ProxyEntityAvailable<SysUser , SysUserProxy> { @Column(primaryKey = true) private String id; private String name; private LocalDateTime createTime; @Navigate(value = RelationTypeEnum.ManyToMany, mappingClass = UserRole.class, selfMappingProperty = "userId", targetMappingProperty = "roleId") private List<SysRole> roles; @Navigate(value = RelationTypeEnum.OneToOne,targetProperty = "userId") private SysUserAddress address; @Override public Class<SysUserProxy> proxyTableClass() { return SysUserProxy.class; } } @Table("t_role") @Data @EntityProxy public class SysRole implements ProxyEntityAvailable<SysRole, SysRoleProxy> { @Column(primaryKey = true) private String id; private String name; private LocalDateTime createTime; @Navigate(value = RelationTypeEnum.ManyToMany, mappingClass = UserRole.class, selfMappingProperty = "roleId", targetMappingProperty = "userId") private List<SysUser> users; @Navigate(value = RelationTypeEnum.ManyToMany, mappingClass = RoleMenu.class, selfMappingProperty = "roleId", targetMappingProperty = "menuId") private List<SysMenu> menus; @Override public Class<SysRoleProxy> proxyTableClass() { return SysRoleProxy.class; } } @Table("t_user_role") @Data @EntityProxy public class UserRole implements ProxyEntityAvailable<UserRole , UserRoleProxy> { @Column(primaryKey = true) private String id; private String userId; private String roleId; @Override public Class<UserRoleProxy> proxyTableClass() { return UserRoleProxy.class; } } @Table("t_menu") @Data @EntityProxy public class SysMenu implements ProxyEntityAvailable<SysMenu , SysMenuProxy> { @Column(primaryKey = true) private String id; private String name; private String route; private String icon; @Navigate(value = RelationTypeEnum.ManyToMany, mappingClass = RoleMenu.class, selfMappingProperty = "menuId", targetMappingProperty = "roleId") private List<SysRole> roles; @Override public Class<SysMenuProxy> proxyTableClass() { return SysMenuProxy.class; } } @Table("t_role_menu") @Data @EntityProxy public class RoleMenu implements ProxyEntityAvailable<RoleMenu , RoleMenuProxy> { @Column(primaryKey = true) private String id; private String roleId; private String menuId; @Override public Class<RoleMenuProxy> proxyTableClass() { return RoleMenuProxy.class; } } @Table("t_user_address") @Data @EntityProxy public class SysUserAddress implements ProxyEntityAvailable<SysUserAddress , SysUserAddressProxy> { @Column(primaryKey = true) private String id; private String userId; private String province; private String city; private String area; private String addr; @Override public Class<SysUserAddressProxy> proxyTableClass() { return SysUserAddressProxy.class; } } 

对应关系为用户和角色是多对多,角色和菜单也是多对多

案例1

查询杭州或绍兴的用户

  List<SysUser> userInHz = easyEntityQuery.queryable(SysUser.class) .where(s -> { //隐式子查询会自动join用户表和地址表 s.or(()->{ s.address().city().eq("杭州市"); s.address().city().eq("绍兴市"); }); }).toList(); SELECT t.`id`, t.`name`, t.`create_time` FROM `t_user` t LEFT JOIN `t_user_address` t1 ON t1.`user_id` = t.`id` WHERE ( t1.`city` = '杭州市' OR t1.`city` = '绍兴市' ) 

查询用户叫做小明的返回小明的姓名和小明所在地址

  List<Draft2<String, String>> userNameAndAddr = easyEntityQuery.queryable(SysUser.class) .where(s -> { s.name().eq("小明"); }).select(s -> Select.DRAFT.of( s.name(), s.address().addr()//隐式join因为用户返回了地址标的地址信息 )).toList(); SELECT t.`name` AS `value1`, t1.`addr` AS `value2` FROM `t_user` t LEFT JOIN `t_user_address` t1 ON t1.`user_id` = t.`id` WHERE t.`name` = '小明' 

案例2

查询用户下面存在角色是收货员的用户

  List<SysUser> 收货员 = easyEntityQuery.queryable(SysUser.class) .where(s -> { s.roles().where(role -> { role.name().eq("收货员"); }).any(); }).toList(); SELECT t.`id`, t.`name`, t.`create_time` FROM `t_user` t WHERE EXISTS ( SELECT 1 FROM `t_role` t1 WHERE EXISTS ( SELECT 1 FROM `t_user_role` t2 WHERE t2.`role_id` = t1.`id` AND t2.`user_id` = t.`id` LIMIT 1 ) AND t1.`name` = '收货员' LIMIT 1 ) 

案例3

查询用户下面存在角色是XX员,并且存在个数大于5个的用户,就是说需要满足用户下面的角色是xx员的起码有5个及以上的

  List<SysUser> 收货员 = easyEntityQuery.queryable(SysUser.class) .where(s -> { //筛选条件为角色集合里面有角色名称叫做xx员的 s.roles().where(role -> { role.name().likeMatchRight("员"); }).count().gt(5L);//count数量大于5个 }).toList(); -- 第1条sql数据 SELECT t.`id`, t.`name`, t.`create_time` FROM `t_user` t WHERE ( SELECT COUNT(*) FROM `t_role` t1 WHERE EXISTS ( SELECT 1 FROM `t_user_role` t2 WHERE t2.`role_id` = t1.`id` AND t2.`user_id` = t.`id` LIMIT 1 ) AND t1.`name` LIKE '%员' ) > 5 

案例4

查询用户下面存在的任意角色不大于2022年创建的

  LocalDateTime localDateTime = LocalDateTime.of(2022, 1, 1, 0, 0); List<SysUser> 收货员 = easyEntityQuery.queryable(SysUser.class) .where(s -> { //筛选条件为角色集合里面有角色最大时间不能大于2022年的 s.roles().max(role -> role.createTime()).lt(localDateTime); }).toList(); SELECT t.`id`, t.`name`, t.`create_time` FROM `t_user` t WHERE ( SELECT MAX(t1.`create_time`) FROM `t_role` t1 WHERE EXISTS ( SELECT 1 FROM `t_user_role` t2 WHERE t2.`role_id` = t1.`id` AND t2.`user_id` = t.`id` LIMIT 1 ) ) < '2022-01-01 00:00' 

案例5

查询每个用户和前3个最早创建的角色(支持分页)适用于评论和评论子表前N个

  List<SysUser> 收货员 = easyEntityQuery.queryable(SysUser.class) //前面的表达式表示要返回roles后面的表示如何返回返回按时间正序的3个 .includes(s -> s.roles(),x->{ x.orderBy(r->r.createTime().asc()).limit(3); }) .toList(); 

案例6

查询用户小明下面的菜单

  //方式1多次查询 List<SysMenu> menus = easyEntityQuery.queryable(SysUser.class) .where(s -> { s.name().eq("小明"); }) .toList(x -> x.roles().flatElement().menus().flatElement()); //方式2一次次查询 List<SysMenu> menus = easyEntityQuery.queryable(SysMenu.class) .where(s -> { //判断菜单下的角色存在角色的用户叫做小明的 s.roles().any(role -> { role.users().any(user -> { user.name().eq("小明"); }); }); }).toList(); -- 第1条sql数据 SELECT t.`id`, t.`name`, t.`route`, t.`icon` FROM `t_menu` t WHERE EXISTS ( SELECT 1 FROM `t_role` t1 WHERE EXISTS ( SELECT 1 FROM `t_role_menu` t2 WHERE t2.`role_id` = t1.`id` AND t2.`menu_id` = t.`id` LIMIT 1 ) AND EXISTS ( SELECT 1 FROM `t_user` t3 WHERE EXISTS ( SELECT 1 FROM `t_user_role` t4 WHERE t4.`user_id` = t3.`id` AND t4.`role_id` = t1.`id` LIMIT 1 ) AND t3.`name` = '小明' LIMIT 1 ) LIMIT 1 ) 

最后

这边展示了非常强大的OLTP查询模式,OLAP也是非常强大可以group+join，实现from (匿名sql) 也可以join (匿名sql)

一款具有强类型OLTP+OLAP的完美解决方案,并且完美支持mybatis系列的任意架构逐步构建迁移,不会产生任何冲突,因为easy-query本身就是零依赖,并且完全免费,完全开源(包括文档！！！包括文档！！！包括文档！！！)

我相信easy-query是一款可以完完全全打动您的ORM作品,也是全java唯一一款全sql替代性产品