Question

我有以下数据：第1列包含许多类别，第2列包含每个类别的值。我需要转换或透视此信息，以显示多列中类别组的每个值。

col1      col2
----------------
1         a    
2         b 
2         c
2         d
3         e
3         f 
4         g
4         h

需要这个结果：

col1      col2     col3     col4   col5   col6   
-----------------------------------------------   
1         a
2         b         c       d
3         e         f 
4         g         h

每个tb1计数（第2列）组（第1列）的值不超过7个。来自tb1第2列的所有值都不同，约为+ 50条记录。

Answer 1

You want to pivot your table, but your table doesn't currently contain the field that you want to pivot on ("col1", "col2", "col3", etc...). You need a row number, partitioned by col1. The Jet database does not provide a ROW_NUMBER function, so you have to fake it by joining the table to itself:

select t1.col1, t1.col2, count(*) as row_num
from [Sheet1$] t1
inner join [Sheet1$] t2 on t2.col1 = t1.col1 and t2.col2 <= t1.col2
group by t1.col1, t1.col2

Now you can pivot on row_num:

transform Min(x.col2) select x.col1
from(
    select t1.col1, t1.col2, count(*) as row_num
    from [Sheet1$] t1
    inner join [Sheet1$] t2 on t2.col1 = t1.col1 and t2.col2 <= t1.col2
    group by t1.col1, t1.col2
    )  x
group by x.col1
pivot x.row_num

选择一列到多列的不同值

1 个答案: