背景
转java后的几年时间里面一直在寻找一个类似.net的orm，不需要很特别的功能，仅希望90%的场景都可以通过强类型语法来编写符合直觉的sql，来操作数据库编写业务。
但是一直没有找到，Mybatis-Plus的单表让我在最初的时间段内看到了希望，不过随着使用的深入越发的觉得Mybatis-Plus只是一个残缺的orm，因为大部分场景不支持表达式或者强类型会导致它本身的很多特性都无法使用，比如你配置了软删除，那么如果你遇到了join不好意思软删除你需要自己处理，很多配置会随着手写sql的加入变的那么的不智能，甚至表现得和sql helper没区别。
别说Mybatis-Plus-Join了，这玩意更逆天，如果一个orm想写出符合自己的sql，需要不断地调试尝试来“拼接”出想要的语句，那么他就称不上一个ORM，连sql builder也算不上。Mybatis-Plus-Join就是这样。
所以在4-5年后我终于忍受不了了，决定自研一款orm。参考现有.net生态十分完整的orm代码和几乎完美符合扩展性和语义性的链式表达式，让.net的orm带到java中。
查询
查询第一条数据
Topic topic = easyQuery.queryable(Topic.class)
.where(o -> o.eq(Topic::getId, "123"))
.firstOrNull();
==> Preparing: SELECT `id`,`stars`,`title`,`create_time` FROM `t_topic` WHERE `id` = ? LIMIT 1
==> Parameters: 123(String)
<== Time Elapsed: 2(ms)
<== Total: 0
查询并断言至多一条数据
Topic topic = easyQuery.queryable(Topic.class)
.where(o -> o.eq(Topic::getId, "123"))
.singleOrNull();
==> Preparing: SELECT `id`,`stars`,`title`,`create_time` FROM `t_topic` WHERE `id` = ?
==> Parameters: 123(String)
<== Time Elapsed: 2(ms)
<== Total: 0
查询多条数据
List topics = easyQuery.queryable(Topic.class)
.where(o -> o.eq(Topic::getId, "123"))
.toList();
==> Preparing: SELECT `id`,`stars`,`title`,`create_time` FROM `t_topic` WHERE `id` = ?
==> Parameters: 123(String)
<== Time Elapsed: 2(ms)
<== Total: 0
查询自定义列
Topic topic = easyQuery.queryable(Topic.class)
.where(o -> o.eq(Topic::getId, "1"))
.select(o->o.column(Topic::getId).column(Topic::getTitle))
.firstOrNull();
==> Preparing: SELECT `id`,`title` FROM `t_topic` WHERE `id` = ? LIMIT 1
==> Parameters: 1(String)
<== Time Elapsed: 2(ms)
<== Total: 1
分页查询
EasyPageResult topicPageResult = easyQuery
.queryable(Topic.class)
.where(o -> o.isNotNull(Topic::getId))
.toPageResult(1, 20);
==> Preparing: SELECT COUNT(1) FROM t_topic t WHERE t.`id` IS NOT NULL
<== Total: 1
==> Preparing: SELECT t.`id`,t.`stars`,t.`title`,t.`create_time` FROM t_topic t WHERE t.`id` IS NOT NULL LIMIT 20
<== Total: 20
将表达式转成匿名表嵌套查询
// SELECT `id`,`title` FROM `t_topic` WHERE `id` = ?
Queryable query = easyQuery.queryable(Topic.class)
.where(o -> o.eq(Topic::getId, "1"))
.select(Topic.class, o -> o.column(Topic::getId).column(Topic::getTitle));
List list = query.leftJoin(Topic.class, (t, t1) -> t.eq(t1, Topic::getId, Topic::getId))
.where((t, t1) -> {
t1.eq(Topic::getId, "123");
t.eq(Topic::getId, "456");
}).toList();
SELECT t1.`id`,t1.`title`
FROM (SELECT t.`id`,t.`title` FROM `t_topic` t WHERE t.`id` = ?) t1
LEFT JOIN `t_topic` t2 ON t1.`id` = t2.`id` WHERE t2.`id` = ? AND t1.`id` = ?
==> Preparing: SELECT t1.`id`,t1.`title` FROM (SELECT t.`id`,t.`title` FROM `t_topic` t WHERE t.`id` = ?) t1 LEFT JOIN `t_topic` t2 ON t1.`id` = t2.`id` WHERE t2.`id` = ? AND t1.`id` = ?
==> Parameters: 1(String),123(String),456(String)
<== Time Elapsed: 5(ms)
<== Total: 0
子查询
//SELECT * FROM `t_blog` t1 WHERE t1.`deleted` = ? AND t1.`id` = ?
Queryable subQueryable = easyQuery.queryable(BlogEntity.class)
.where(o -> o.eq(BlogEntity::getId
, "1"));
List x = easyQuery
.queryable(Topic.class).where(o -> o.exists(subQueryable.where(q -> q.eq(o, BlogEntity::getId, Topic::getId)))).toList();
==> Preparing: SELECT t.`id`,t.`stars`,t.`title`,t.`create_time` FROM `t_topic` t WHERE EXISTS (SELECT 1 FROM `t_blog` t1 WHERE t1.`deleted` = ? AND t1.`id` = ? AND t1.`id` = t.`id`)
==> Parameters: false(Boolean),1(String)
<== Time Elapsed: 3(ms)
<== Total: 1
多表join查询
Topic topic = easyQuery
.queryable(Topic.class)
.leftJoin(BlogEntity.class, (t, t1) -> t.eq(t1, Topic::getId, BlogEntity::getId))
.where(o -> o.eq(Topic::getId, "3"))
.firstOrNull();
==> Preparing: SELECT t.`id`,t.`stars`,t.`title`,t.`create_time` FROM t_topic t LEFT JOIN t_blog t1 ON t1.`deleted` = ? AND t.`id` = t1.`id` WHERE t.`id` = ? LIMIT 1
==> Parameters: false(Boolean),3(String)
<== Total: 1
流式结果大数据迭代返回
try(JdbcStreamResult streamResult = easyQuery.queryable(BlogEntity.class).where(o -> o.le(BlogEntity::getStar, 100)).orderByAsc(o -> o.column(BlogEntity::getCreateTime)).toStreamResult()){
LocalDateTime begin = LocalDateTime.of(2020, 1, 1, 1, 1, 1);
int i = 0;
for (BlogEntity blog : streamResult.getStreamIterable()) {
String indexStr = String.valueOf(i);
Assert.assertEquals(indexStr, blog.getId());
Assert.assertEquals(indexStr, blog.getCreateBy());
Assert.assertEquals(begin.plusDays(i), blog.getCreateTime());
Assert.assertEquals(indexStr, blog.getUpdateBy());
Assert.assertEquals(begin.plusDays(i), blog.getUpdateTime());
Assert.assertEquals("title" + indexStr, blog.getTitle());
// Assert.assertEquals("content" + indexStr, blog.getContent());
Assert.assertEquals("http://blog.easy-query.com/" + indexStr, blog.getUrl());
Assert.assertEquals(i, (int) blog.getStar());
Assert.assertEquals(0, new BigDecimal("1.2").compareTo(blog.getScore()));
Assert.assertEquals(i % 3 == 0 ? 0 : 1, (int) blog.getStatus());
Assert.assertEquals(0, new BigDecimal("1.2").multiply(BigDecimal.valueOf(i)).compareTo(blog.getOrder()));
Assert.assertEquals(i % 2 == 0, blog.getIsTop());
Assert.assertEquals(i % 2 == 0, blog.getTop());
Assert.assertEquals(false, blog.getDeleted());
i++;
}
} catch (SQLException e) {
throw new RuntimeException(e);
}
==> Preparing: SELECT `id`,`create_time`,`update_time`,`create_by`,`update_by`,`deleted`,`title`,`content`,`url`,`star`,`publish_time`,`score`,`status`,`order`,`is_top`,`top` FROM `t_blog` WHERE `deleted` = ? AND `star` <= ? ORDER BY `create_time` ASC
==> Parameters: false(Boolean),100(Integer)
<== Time Elapsed: 6(ms)
自定义VO返回
List list = easyQuery
.queryable(Topic.class)
//第一个join采用双参数,参数1表示第一张表Topic 参数2表示第二张表 BlogEntity
.leftJoin(BlogEntity.class, (t, t1) -> t.eq(t1, Topic::getId, BlogEntity::getId))
//第二个join采用三参数,参数1表示第一张表Topic 参数2表示第二张表 BlogEntity 第三个参数表示第三张表 SysUser
.leftJoin(SysUser.class, (t, t1, t2) -> t.eq(t2, Topic::getId, SysUser::getId))
.where(o -> o.eq(Topic::getId, "123"))//单个条件where参数为主表Topic
//支持单个参数或者全参数,全参数个数为主表+join表个数 链式写法期间可以通过then来切换操作表
.where((t, t1, t2) -> t.eq(Topic::getId, "123").then(t1).like(BlogEntity::getTitle, "456")
.then(t2).eq(BaseEntity::getCreateTime, LocalDateTime.now()))
//如果不想用链式的then来切换也可以通过lambda 大括号方式执行顺序就是代码顺序,默认采用and链接
.where((t, t1, t2) -> {
t.eq(Topic::getId, "123");
t1.like(BlogEntity::getTitle, "456");
t1.eq(BaseEntity::getCreateTime, LocalDateTime.now());
})
.select(QueryVO.class, (t, t1, t2) ->
//将第一张表的所有属性的列映射到vo的列名上,第一张表也可以通过columnAll将全部字段映射上去
// ,如果后续可以通过ignore方法来取消掉之前的映射关系
t.column(Topic::getId)
.then(t1)
//将第二张表的title字段映射到VO的field1字段上
.columnAs(BlogEntity::getTitle, QueryVO::getField1)
.then(t2)
//将第三张表的id字段映射到VO的field2字段上
.columnAs(SysUser::getId, QueryVO::getField2)
).toList();
表单条件动态查询
BlogQuery2Request query = new BlogQuery2Request();
query.setContent("标题");
query.setPublishTimeEnd(LocalDateTime.now());
query.setStatusList(Arrays.asList(1,2));
List queryable = easyQuery.queryable(BlogEntity.class)
.whereObject(query).toList();
==> Preparing: SELECT `id`,`create_time`,`update_time`,`create_by`,`update_by`,`deleted`,`title`,`content`,`url`,`star`,`publish_time`,`score`,`status`,`order`,`is_top`,`top` FROM `t_blog` WHERE `deleted` = ? AND `content` LIKE ? AND `publish_time` <= ? AND `status` IN (?,?)
==> Parameters: false(Boolean),%标题%(String),2023-07-14T22:37:47.880(LocalDateTime),1(Integer),2(Integer)
<== Time Elapsed: 2(ms)
<== Total: 0
基本类型结果返回
List list = easyQuery.queryable(Topic.class)
.where(o -> o.eq(Topic::getId, "1"))
.select(String.class, o -> o.column(Topic::getId))
.toList();
==> Preparing: SELECT t.`id` FROM `t_topic` t WHERE t.`id` = ?
==> Parameters: 1(String)
<== Time Elapsed: 2(ms)
<== Total: 1
分组查询
List topicGroupTestDTOS = easyQuery.queryable(Topic.class)
.where(o -> o.eq(Topic::getId, "3"))
.groupBy(o->o.column(Topic::getId))
.select(TopicGroupTestDTO.class, o->o
