sql case查询的使用

select a.branchcode,
       (case a.branchname
         when '全国' then
          '全国'
         when '广东' then
          '粤'
         when '湖南' then
          '湘'
         when '湖北' then
          '鄂'
         when '四川' then
          '川'
         when '山东' then
          '鲁'
         when '江苏' then
          '苏'
         when '重庆' then
          '渝'
         when '河北' then
          '冀'
         when '上海' then
          '沪'
         when '安徽' then
          '皖'
         when '天津' then
          '津'
         when '浙江' then
          '浙'
         when '北京' then
          '京'
         when '河南' then
          '豫'
         when '辽宁' then
          '辽'
         when '深圳' then
          '深'
         when '福建' then
          '闽'
         when '大连' then
          '粤'
         when '广东' then
          '粤'
         when '厦门' then
          '粤'
       end) branchname,
       (case branchname
         when '全国' then
          dayvalueprem_pre || '万'
         else
          dayvalueprem_pre || ''
       end) aaadayvalueprem_pre, --日预收
       a.monthvalueprem_pre, --月预收
       a.monthvalueprem, --月核保价保
       a.achievementrate, --月核保达成
       a.activeresource --人力
  from reportbroker a
 where a.reportdate = '2012-06-07'
   and a.reporttype in ('A01_0', 'A01_1')
   and a.branchname not in ('厦门', '大连')
 order by branchcode;