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
