Question

我正在写一个查询，其中一个字段是DIAL_NUMBER。某些值为11位，有些值为该字段中的10位数。它是11位数我需要第2到第7个字符，而它是10位数我需要第1到第6个字符。然后我需要计算每个系列。我尝试使用以下方法，这是错误的。请帮我确定解决方案。

select dialled number, case
when length(Dialled_Number) = '11' then Substr(Dialled_Number, 2, 7)
else Substr(Dialled_Number, 1, 6)
end
count(*)
from Error_Event

Answer 1

在不知道您的预期结果的情况下，我想您需要在查询中使用group by。

也许是这样的：

select case
       when length(Dialled_Number) = 11 then Substr(Dialled_Number, 2, 7)
       else Substr(Dialled_Number, 1, 6)
       end, 
    count(*)
from Error_Event
group by case
       when length(Dialled_Number) = 11 then Substr(Dialled_Number, 2, 7)
       else Substr(Dialled_Number, 1, 6)
       end

SQL Fiddle Demo

Answer 2

如果是MS SQL，您可以使用ROW_NUMBER()和COUNT函数来获得所需的输出。

DECLARE @TABLE TABLE(DIAL_NUMBER VARCHAR(20))
INSERT INTO @TABLE
SELECT '81243193812' UNION
SELECT '1829321874' UNION
SELECT '182932'


SELECT NPANXX, [Count] FROM
(
    SELECT NPANXX,
    COUNT(NPANXX) OVER (PARTITION BY NPANXX) AS [Count], DIAL_NUMBER,
    ROW_NUMBER() OVER (PARTITION BY NPANXX ORDER BY DIAL_NUMBER) RN
     FROM
    (
        SELECT DIAL_NUMBER, 
        CASE
            WHEN LEN(DIAL_NUMBER) = 11 THEN SUBSTRING(DIAL_NUMBER,2, 7)
            ELSE SUBSTRING(DIAL_NUMBER,1, 6)
        END AS NPANXX
        FROM @table
    ) Tmp
)FTMp
WHERE RN = 1

Sql Fiddle

用于计算每个NPANXX系列的SQL语句

2 个答案: