Question

我想做的是：

1月表

Cusip编号：1,2,3

当前因素：.123，.140，.045

二月表

Cusip编号：1,2,3

当前因素：.184，.163，.033

然后在FEB表中找到一个新列，找到每个CUSIP号的2月因子/ jan因子的值：

= 123 / 0.184

=。140 / 0.163

等。

这是我到目前为止从上个月拉出因子并将其显示在2月表之下

SELECT [CURRENT FACTOR]
FROM DBO.mbs012013, DBO.mbs022013
WHERE DBO.mbs012013.[CUSIP NUMBER] = DBO.mbs022013.[CUSIP NUMBER]

Answer 1

Update February 
  Set factor= (1.0 * January.factor/February.factor )
  from February 
  Join Janaury on .... whatever links Febuary to January which had better be a 1-1 join

Answer 2

  SELECT February.CUSIP, February.factor, (1.0 * January.factor/February.factor ) as Ratio
  from February 
  INNER JOIN Janaury on January.CUSIP = February.CUSIP

SQL：我想使用两个具有相同名称的列来计算新列中的值

2 个答案: