Match Dates from two tables

[GabyArco]

Hi,

I have two tables, one with sample dates and corresponding temperature values, and a second table with height values and the dates when these height values were taken:

Table_1_Samples
Sample_Date	Temperature
3/3/13	20
3/6/13	18
3/15/13	21
3/20/13	20
4/1/13	16
4/7/13	20
4/18/13	17

Table_2_Heights
Height_Date	Height
3/1/13	15
3/7/13	20
3/19/13	13
4/15/13	17

I need to know, for each sample date and temperature, when was the last height measurement taken and what was that height. The output should look something like this:

Sample_Date Temperature Last_Height_Date Height 3/3/13 20 ? ? 3/6/13 18 ? ? 3/15/13 21 ? ? 3/20/13 20 ? ? 4/1/13 16 ? ? 4/7/13 20 ? ? 4/18/13 17 ? ?

So, for the first sample date (3/3/13), the last height date should be 3/1/13 and the height should be "15", for the second to last sample date (4/7/13), the last height date should be "3/19/13" and the corresponding height should be "13".

What is the best way to query my tables to generate these two new columns with the right information? All and any help is greatly appreciated. I've been trying to solve this on my own, and I can't figure it out.
Thanks!!

[GabyArco]

Using the SQL expression

SELECT Sample_Date.Sample_Date, Sample_Date.Temperature, Height.Height_Date, Height.Height
FROM Sample_Date, Height
WHERE Height.Height_Date <= Sample_Date.Sample_Date

I get

Sample_Date	Temperature	Height_Date	Height
3/3/2013	20	3/1/2013	15
3/6/2013	18	3/1/2013	15
3/15/2013	21	3/1/2013	15
3/15/2013	21	3/7/2013	20
3/20/2013	20	3/1/2013	15
3/20/2013	20	3/7/2013	20
3/20/2013	20	3/19/2013	13
4/1/2013	16	3/1/2013	15
4/1/2013	16	3/7/2013	20
4/1/2013	16	3/19/2013	13
4/7/2013	20	3/1/2013	15
4/7/2013	20	3/7/2013	20
4/7/2013	20	3/19/2013	13
4/18/2013	17	3/1/2013	15
4/18/2013	17	3/7/2013	20
4/18/2013	17	3/19/2013	13
4/18/2013	17	4/15/2013	17

I would like to only get one record per sample date, i.e. for every sample date *only* the closest dated height. Thanks!

[rzw0wr]

Just by looking I would say your table are not related as they should be.
If they are not related I cannot see a way to filter them.
To put them together you have to have something in common between the 2 records.
Can you show us a picture of your tables?

Dale