pgsql怎么 获取一段时间日期的星期几。比如我查询今年一整年的数据，不仅要每天的日期还要带上星期几。这个sql怎么写啊？
参考下
select case
when (EXTRACT (dow FROM DATE (now( ))))='0.0' then '星期日'
when (EXTRACT (dow FROM DATE (now( ))))='1.0' then '星期一'
when (EXTRACT (dow FROM DATE (now( ))))='2.0' then '星期二'
when (EXTRACT (dow FROM DATE (now( ))))='3.0' then '星期三'
when (EXTRACT (dow FROM DATE (now( ))))='4.0' then '星期四'
when (EXTRACT (dow FROM DATE (now( ))))='5.0' then '星期五'
when (EXTRACT (dow FROM DATE (now( ))))='6.0' then '星期六'
end