Question

I have a table (Table A) with a field of integers (Field B). For each row of Table A, I would like to construct a range of +/- 100 surrounding the integer value of Field B then find all values from Field B that are within these ranges. The query needs to be performed for all values in Field B. The query needs to return each row that is within each row range. Here is an example of what I am trying to do:

Table A
_______
A    1000    
B    3000    
C    5000    
D    1090   

Using the above Table A, the query would first find the ranges (+/- 100) for all integers in Field B.

900 - 1100
2900 - 3100
4900 - 5100
990 - 1190

The query would then iterate through these ranges and return rows from Table A that fall within the generated ranges. Using the above example, the query would return:

A    1000
A    1000
B    3000
C    5000
D    1090
D    1090

A and D are returned twice because it they fall within their own ranges. How can I construct a query that will return each row that falls between the range of each row? Thanks in advance for the help.

Answer 1

SELECT t2.*
FROM tableA AS t1
INNER JOIN tableA AS t2 ON t2.fieldB >= (t1.fieldB - 100) AND t2.fieldB <= (t1.fieldB + 100)

Shouldn’t A also be shown twice, since it’s also in D’s range? (that’s the case with above query – if incorrect, please elaborate why ^^)