查询时自定义排序字段和排序规则

指定字段排序

平台默认排序字段，参考IdModel，按创建时间和ID倒序(ordering = "createDate DESC, id DESC")

方法1：模型指定排序

模型定义增加排序字段。@Model.Advanced(ordering = "xxxxx DESC, yyyy DESC")

@Model.model(PetShop.MODEL_MODEL)
@Model(displayName = "宠物店铺",summary="宠物店铺",labelFields ={"shopName"})
@Model.Code(sequence = "DATE_ORDERLY_SEQ",prefix = "P",size=6,step=1,initial = 10000,format = "yyyyMMdd")
@Model.Advanced(ordering = "createDate DESC")
public class PetShop extends AbstractDemoIdModel {
       public static final String MODEL_MODEL="demo.PetShop";
       // …………
}

方法2：Page查询中可以自定排序规则

• API参考 pro.shushi.pamirs.meta.api.dto.condition.Pagination#orderBy

  public <G, R> Pagination<T> orderBy(SortDirectionEnum direction, Getter<G, R> getter) {
   if (null == getSort()) {
       setSort(new Sort());
   }
   getSort().addOrder(direction, getter);
   return this;
  }

• 具体示例

  @Function.Advanced(type= FunctionTypeEnum.QUERY)
  @Function.fun(FunctionConstants.queryPage)
  @Function(openLevel = {FunctionOpenEnum.API})
  public Pagination<PetShop> queryPage(Pagination<PetShop> page, IWrapper<PetShop> queryWrapper){
   page.orderBy(SortDirectionEnum.DESC, PetShop::getCreateDate);
   page = new PetShop().queryPage(page, queryWrapper);
   return page;
  }

方法3：查询的wapper中指定

• API参考：pro.shushi.pamirs.framework.connectors.data.sql.AbstractWrapper#orderBy

  @Override
  public Children orderBy(boolean condition, boolean isAsc, R... columns) {
  if (ArrayUtils.isEmpty(columns)) {
      return typedThis;
  }
  SqlKeyword mode = isAsc ? ASC : DESC;
  for (R column : columns) {
      doIt(condition, ORDER_BY, columnToString(column), mode);
  }
  return typedThis;
  }

具体示例

public List<PetShop> queryList(String name) {
    List<PetShop> petShops = Models.origin().queryListByWrapper(
            Pops.<PetShop>lambdaQuery().from(PetShop.MODEL_MODEL)
                    .orderBy(true, true, PetShop::getCreateDate)
                   .orderBy(true, true, PetShop::getId)
                    .like(PetShop::getShopName, name));
    return petShops;
}

设置查询不排序

方法1：关闭平台默认排序字段，设置模型的ordering，改成：ordering = "1=1"

模型定义增加排序字段。@Model.Advanced(ordering = "1=1")

@Model.model(PetShop.MODEL_MODEL)
@Model(displayName = "宠物店铺",summary="宠物店铺",labelFields ={"shopName"})
@Model.Code(sequence = "DATE_ORDERLY_SEQ",prefix = "P",size=6,step=1,initial = 10000,format = "yyyyMMdd")
@Model.Advanced(ordering = "1=1")
public class PetShop extends AbstractDemoIdModel {
       public static final String MODEL_MODEL="demo.PetShop";
       // …………
}

在ORDER BY 1=1中，1=1是一个条件表达式，它总是会返回true（或者在某些数据库中是1），因为1等于1。因此，这个条件实际上没有改变排序的结果，结果仍然会按照默认的顺序进行排序。这种写法通常用于一些动态生成SQL语句的场景中，可以在不知道具体列名的情况下按照顺序进行排序。

所以，ORDER BY 1=1实际上等效于没有使用ORDER BY子句，或者说是按照默认顺序进行排序。

方法2：查询是设置Sortable属性

// 示例1：
LambdaQueryWrapper<PetShop> query = Pops.<PetShop>lambdaQuery();
query.from(PetShop.MODEL_MODEL);
query.setSortable(Boolean.FALSE);
query.orderBy(true, true, PetShop::getId);
List<PetShop> petShops2 = new PetShop().queryList(query);
System.out.printf(petShops2.size() + "");

// 示例2：
List<PetShop> petShops3 = new PetShop().queryList(
        Pops.<PetShop>lambdaQuery().from(PetShop.MODEL_MODEL).setSortable(Boolean.FALSE));
System.out.printf(petShops3.size() + "");

// 示例3：
IWrapper<PetShop> wrapper = Pops.<PetShop>lambdaQuery()
        .from(PetShop.MODEL_MODEL).setBatchSize(-1).setSortable(Boolean.FALSE);
List<PetShop> petShops4 = new PetShop().queryList(wrapper);
System.out.printf(petShops4.size() + "");

// 示例4：
QueryWrapper<PetShop> wrapper2 = new QueryWrapper<PetShop>().from(PetShop.MODEL_MODEL).setSortable(Boolean.FALSE);
List<PetShop> petShops5 = new PetShop().queryList(wrapper2);
System.out.printf(petShops5.size() + "");