Andy Colson wrote
> On 4/3/2014 10:27 AM, Schnabel, Robert D. wrote:
>> I'm trying to figure out how to count the number of rows within a fixed
>> range of the current row value. My table looks like this:
>>
>> SELECT chr_pos
>> FROM mutations_crosstab_9615_99
>> WHERE bta = 38
>> LIMIT 10
>>
>> chr_pos
>> 138
>> 140
>> 163
>> 174
>> 187
>> 187
>> 188
>> 208
>> 210
>> 213
>>
>
> This is the answer I got, which is different than yours, but I think its
> right.
>
>
> chr_pos | count
> ---------+-------
> 138 | 2
> 140 | 2
> 163 | 2
> 174 | 4
> 187 | 3
> 188 | 4
> 208 | 5
> 210 | 4
> 212 | 4
> 213 | 4
> (10 rows)
Same concept as mine - but I'm not sure where the "212" came from and you
did not duplicate the "187" that was present in the original.
The OP wanted to show the duplicate row - which yours does and mine does not
- but depending on how many duplicates there are having to run the same
effective query multiple times knowing you will always get the same result
seems inefficient. Better to query over a distinct set of values and then,
if needed, join that back onto the original dataset.
David J.
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