分页

easy-query提供了非常简易的分页查询功能,方便用户进行数据结果的分页查询

简单分页

   EasyPageResult<Topic> 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

join分页

EasyPageResult<BlogEntity> page = easyQuery
            .queryable(Topic.class)
            .innerJoin(BlogEntity.class, (t, t1) -> t.eq(t1, Topic::getId, BlogEntity::getId))
            .where((t, t1) -> t1.isNotNull(BlogEntity::getTitle).then(t).eq(Topic::getId, "3"))
            .select(BlogEntity.class, (t, t1) -> t1.columnAll().columnIgnore(BlogEntity::getId))
            .toPageResult(1, 20);

==> Preparing: SELECT  COUNT(1)  FROM t_topic t INNER JOIN t_blog t1 ON t.`id` = t1.`id` WHERE t1.`title` IS NOT NULL AND t.`id` = ?
==> Parameters: 3(String)
<== Total: 1, Query Use: 3(ms)
==> Preparing: SELECT t1.`create_time`,t1.`update_time`,t1.`create_by`,t1.`update_by`,t1.`deleted`,t1.`title`,t1.`content`,t1.`url`,t1.`star`,t1.`publish_time`,t1.`score`,t1.`status`,t1.`order`,t1.`is_top`,t1.`top` FROM t_topic t INNER JOIN t_blog t1 ON t.`id` = t1.`id` WHERE t1.`title` IS NOT NULL AND t.`id` = ? LIMIT 1
==> Parameters: 3(String)
<== Total: 1, Query Use: 2(ms)

group分页

EasyPageResult<BlogEntity> page = easyQuery
                .queryable(Topic.class)
                .innerJoin(BlogEntity.class, (t, t1) -> t.eq(t1, Topic::getId, BlogEntity::getId))
                .where((t, t1) -> t1.isNotNull(BlogEntity::getTitle))
                .groupBy((t, t1)->t1.column(BlogEntity::getId))
                .select(BlogEntity.class, (t, t1) -> t1.column(BlogEntity::getId).columnSum(BlogEntity::getScore))
                .toPageResult(1, 20);

==> Preparing: SELECT  COUNT(1)  FROM (SELECT t1.`id`,SUM(t1.`score`) AS `score` FROM t_topic t INNER JOIN t_blog t1 ON t.`id` = t1.`id` WHERE t1.`title` IS NOT NULL GROUP BY t1.`id`) t2
<== Total: 1, Query Use: 8(ms)
==> Preparing: SELECT t1.`id`,SUM(t1.`score`) AS `score` FROM t_topic t INNER JOIN t_blog t1 ON t.`id` = t1.`id` WHERE t1.`title` IS NOT NULL GROUP BY t1.`id` LIMIT 20
<== Total: 20, Query Use: 2(ms)

自定义分页返回结果

easy-query提供了自定义分页返回结果,用户可以自行定义分页结果,《替换框架行为❗️❗️❗️》

替换接口

EasyPageResultProvider

方法	参数	描述
createPageResult	long pageIndex, long pageSize,long total, List<T> data	返回toPageResult的分页对象
createShardingPageResult	long pageIndex, long pageSize,long total, List<T> data,SequenceCountLine sequenceCountLine	返回toShardingPageResult的分页对象

默认实现

public class DefaultEasyPageResultProvider implements EasyPageResultProvider{
    @Override
    public <T> EasyPageResult<T> createPageResult(long pageIndex, long pageSize,long total, List<T> data) {
        return new DefaultPageResult<>(total,data);
    }

    @Override
    public <T> EasyPageResult<T> createShardingPageResult(long pageIndex, long pageSize,long total, List<T> data,SequenceCountLine sequenceCountLine) {
        return new DefaultShardingPageResult<>(total,data,sequenceCountLine);
    }
}


public class DefaultPageResult<T> implements EasyPageResult<T> {
    private final long total;
    private final List<T> data;

    public DefaultPageResult(long total, List<T> data) {
        this.total = total;

        this.data = data;
    }

    public long getTotal() {
        return total;
    }

    public List<T> getData() {
        return data;
    }
}

public interface EasyShardingPageResult<T> extends EasyPageResult<T>{
    List<Long> getTotalLines();
}


public class DefaultShardingPageResult<T> implements EasyShardingPageResult<T> {
    private final long total;
    private final List<T> data;
    private final SequenceCountLine sequenceCountLine;

    public DefaultShardingPageResult(long total, List<T> data,SequenceCountLine sequenceCountLine) {
        this.total = total;

        this.data = data;
        this.sequenceCountLine = sequenceCountLine;
    }

    public long getTotal() {
        return total;
    }

    public List<T> getData() {
        return data;
    }

    @Override
    public List<Long> getTotalLines() {
        return sequenceCountLine.getTotalLines();
    }
}

无依赖使用自己的PageResult

很多时候框架提供的EasyPageResult<T>提供了方便的同时让整个项目高度依赖easy-query这是一个非常不好的事情,所以easy-query在1.4.25提供了自定义PageResult<TResult>结果,并且提供了链式方法调用方便开发人员

框架提供的分页器

Pager<TEntity,TPageResult> 用户可以自行实现分页

添加自己的分页返回结果接口

//接口
public interface PageResult<T> {
    /**
     * 返回总数
     * @return
     */
    long getTotalCount();

    /**
     * 结果内容 
     * @return
     */
    List<T> getList();
}

//实现
public class MyPageResult<TEntity> implements PageResult<TEntity> {
    private final long total;
    private final List<TEntity> list;

    public MyPageResult(long total, List<TEntity> list){

        this.total = total;
        this.list = list;
    }
    @Override
    public long getTotalCount() {
        return total;
    }

    @Override
    public List<TEntity> getList() {
        return list;
    }
}

自定义pager

public class MyPager<TEntity> implements Pager<TEntity,PageResult<TEntity>> {
    private final long pageIndex;
    private final long pageSize;
    private final long pageTotal;

    public MyPager(long pageIndex, long pageSize){
        this(pageIndex,pageSize,-1);
    }
    public MyPager(long pageIndex, long pageSize, long pageTotal){

        this.pageIndex = pageIndex;
        this.pageSize = pageSize;
        this.pageTotal = pageTotal;
    }
    @Override
    public PageResult<TEntity> toResult(Query<TEntity> query) {
        EasyPageResult<TEntity> pageResult = query.toPageResult(pageIndex, pageSize,pageTotal);
        return new MyPageResult<>(pageResult.getTotal(),pageResult.getData());
    }
}

测试代码

//业务代码返回自定义PageResult<TEntity>
PageResult<TopicGenericKey> pageResult = easyQuery
        .queryable(TopicGenericKey.class)
        .whereById("1")
        .toPageResult(new MyPager<>(1, 2));
Assert.assertEquals(1,pageResult.getTotalCount());
Assert.assertEquals("1",pageResult.getList().get(0).getId());