爱喝咖啡的番薯(提问者)其实这句话我之前是明白,完整的句子是这样的:case when datename between to_char(ADD_MONTHS(trunc(to_date(\'${datename}\',\'yyyymmdd\'),\'Q\'),-3),\'yyyymmdd\') and \'${datename}\' then QUARTER_NAME end QUARTER_NAME,
case when datename between to_char(ADD_MONTHS(trunc(to_date(\'${datename}\',\'yyyymmdd\'),\'mm\'),-2),\'yyyymmdd\') and \'${datename}\' then MONTH_NAME end MONTH_NAME,
case when datename between to_char(trunc(to_date(\'${datename}\',\'yyyymmdd\'),\'iw\')-21,\'yyyymmdd\') and \'${datename}\' then week_name end week_name,
这句话是在定义什么嘞