org.postgresql.util.PSQLException:错误：语法错误位于或接近；及；

我得到了这个postgresql异常。这是我的疑问：

select * from (\
  select \
   st.station_type_id as "id", \
     case when \
      ( \
        mast.station_type_desc is null \
      ) \
      then st.station_type_desc else mast.station_type_desc end as "description" \
      from station_type st left outer \
           join master_agent_station_type mast on st.station_type_id = mast.station_type_id \
      and mast.party_id='%s' where st.is_active='Y'\
) as result

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我是postgresql新手。

删除那些反斜杠它们在SQL语句中无效请用位置引用整个错误。。。