MyBatis foreach用法

Mapper.xml：

 
select  c.city_id as "cityId",
c.city_name as "cityName",
d.city_name as "countryName",
b.neighborhood_name as "neighborhoodName",
count(a.gather_id) NBSUM 
  from event_raw_${item} a
  left join cus_eponcustomer b on a.sourceip = b.device_olt_ip
  left join tab_city c on b.city_id = c.city_id
  left join tab_city d on b.district_id=d.city_id
  where 1=1
 
  and c.city_id=#{cityId} 
 
 
  and c.parent_id=#{cityId}
 
 
 
 
  = ${startTime}]]>

  group by c.city_id,c.city_name,d.city_name,b.neighborhood_name

  order by NBSUM desc

servImpl：

private Map queryParams(Map params)
{
try
{
// 得到指定日期内的所有符合条件的表
List tableList1 = new ArrayList();
List tableList = DBUtil.getExistTableNames(startTime * 1000L,
endTime * 1000L, Calendar.WEEK_OF_YEAR, 1, "event_raw_", "yyyy_w");
for (String tableName : tableList)
{
String tableName1 = tableName.substring(10);
tableList1.add(tableName1);
}
params.put("tablelist", tableList1);
log.info("tablelist=" + tableList1);// tablelist=[2017_13, 2017_14, 2017_15, 2017_16]
log.info("【serv params=】" + params);
}
catch (Exception e)
{
log.error("【serv 传入参数有误】" + e.getMessage());
}
return params;
}

放在order by之前，只能排序一次。

item:集合中每一个元素进行迭代时的别名

index:在迭代过程中，每次迭代到的位置

separator:每次进行迭代之间以什么符号作为分隔 符