oracle中对排序的总结(按照拼音、部首、笔画排序功能 )
-- 按拼音排序 (系统默认)
select * from perexl order by nlssort(tangle,'NLS_SORT=SCHINESE_PINYIN_M');
-- 按部首排序
select * from perexl order by nlssort(tangle,'NLS_SORT=SCHINESE_STROKE_M');
-- 按笔画排序
select * from perexl order by nlssort(tangle,'NLS_SORT=SCHINESE_RADICAL_M');
--排序后获取第一行数据
select * from (select * from perexl order by nlssort(tangle,'NLS_SORT=SCHINESE_PINYIN_M') )C where rownum=1
--降序排序
select * from perexl order by zongrshu desc
--升序排序
select * from perexl order by zongrshu asc
--将nulls始终放在最前
select * from perexl order by tangle nulls first
--将nulls始终放在最后
select * from perexl order by tangle desc nulls last
--decode函数比nvl函数更强大,同样它也可以将输入参数为空时转换为一特定值
select * from perexl order by decode(tangle,null,'单位是空', tangle)
-- 标准的rownum分页查询使用方法
select *from (select c.*, rownum rn from personnel c)where rn >= 1and rn <= 5
--在oracle语句rownum对排序分页的解决方案
--但是如果, 加上order by 姓名 排序则数据显示不正确
select *from (select c.*, rownum rn from personnel c order by 出生年月)where rn >= 1and rn <= 5
--解决方法,再加一层查询,则可以解决
select *from (select rownum rn, t.*from (select 姓名, 出生年月 from personnel order by 出生年月 desc) t)where rn >= 1and rn <= 5
--如果要考虑到效率的问题,上面的还可以优化成(主要两者区别)
select *from (select rownum rn, t.*from (select 姓名,出生年月 from personnel order by 出生年月 desc) t where rownum <= 10) where rn >= 3
--nvl函数可以将输入参数为空时转换为一特定值,下面就是当单位为空的时候转换成“单位是空”
select * from perexl order by nvl(tangle,'单位是空')
select * from perexl order by nlssort(tangle,'NLS_SORT=SCHINESE_PINYIN_M');
-- 按部首排序
select * from perexl order by nlssort(tangle,'NLS_SORT=SCHINESE_STROKE_M');
-- 按笔画排序
select * from perexl order by nlssort(tangle,'NLS_SORT=SCHINESE_RADICAL_M');
--排序后获取第一行数据
select * from (select * from perexl order by nlssort(tangle,'NLS_SORT=SCHINESE_PINYIN_M') )C where rownum=1
--降序排序
select * from perexl order by zongrshu desc
--升序排序
select * from perexl order by zongrshu asc
--将nulls始终放在最前
select * from perexl order by tangle nulls first
--将nulls始终放在最后
select * from perexl order by tangle desc nulls last
--decode函数比nvl函数更强大,同样它也可以将输入参数为空时转换为一特定值
select * from perexl order by decode(tangle,null,'单位是空', tangle)
-- 标准的rownum分页查询使用方法
select *from (select c.*, rownum rn from personnel c)where rn >= 1and rn <= 5
--在oracle语句rownum对排序分页的解决方案
--但是如果, 加上order by 姓名 排序则数据显示不正确
select *from (select c.*, rownum rn from personnel c order by 出生年月)where rn >= 1and rn <= 5
--解决方法,再加一层查询,则可以解决
select *from (select rownum rn, t.*from (select 姓名, 出生年月 from personnel order by 出生年月 desc) t)where rn >= 1and rn <= 5
--如果要考虑到效率的问题,上面的还可以优化成(主要两者区别)
select *from (select rownum rn, t.*from (select 姓名,出生年月 from personnel order by 出生年月 desc) t where rownum <= 10) where rn >= 3
--nvl函数可以将输入参数为空时转换为一特定值,下面就是当单位为空的时候转换成“单位是空”
select * from perexl order by nvl(tangle,'单位是空')