sql - 如何在结果数据中添加字母

Question

当我运行以下查询时，

select
 NVL(week, 'SUM) week
  , sum(A) AS A, sum(B) AS B
from
  (
  select b.* 
     from TABLE  b
    where b.week between '2013051' and '2013052'
  )
 group by ROLLUP(WEEK)

我得到像

   |  WEEK  | 

    2013051

    2013052

但我希望数据命名如下。

   |  WEEK  | 

2013. 05. 1 WEEK 

2013. 05. 2 WEEK

谁能帮我解决这个问题？

Answer 1

假设week是一个字符串：

select substr(week, 1, 4)
    ||'. '|| substr(week, 5, 2)
    ||'. '|| substr(week, 7, 1) ||' WEEK' as week,
...

或者如果week可以为空（由于您的子查询的过滤器，它不能从您的数据中获取，但您从您的数据中获得了一个rollup我最初错过的生成的空值）：

select case when week is null then 'SUM'
    else substr(week, 1, 4)
        ||'. '|| substr(week, 5, 2)
        ||'. '|| substr(week, 7, 1) ||' WEEK' end as week,
...

WEEK                      A          B
---------------- ---------- ----------
2013. 05. 1 WEEK          1          2 
2013. 05. 2 WEEK          3          4 
SUM                       4          6 

SQL Fiddle 演示；一个没有 subquery，这在这里似乎是多余的。

Answer 2

如果您的 Oracle RDBMS 版本为 10g 或更高版本，则regexp_replace函数也可用于执行自定义字符串格式化：

select regexp_replace( 
         week, -- if week is of varchar2 datatype or to_char(week) if it's of number datatype
         '^([[:digit:]]{4})([[:digit:]]{2})([[:digit:]]{1})$', '\1. \2. \3  WEEK'
       )
  from your_table_name_or_subquery

结果：

WEEK    
------------------
2013. 05. 1 WEEK 
2013. 05. 2 WEEK