can sql functions such as min() or max() destroy record integrity

Question

Can functions such as Min() or Max() possibly destroy the integrity of a record? Take the case of the query I recently crafted:

SELECT account, MIN(phone), MIN(chargeid), MIN(locationid) FROM import1 GROUP BY account, phone

is there any chance I am mixing my field data into a new record unintentionally? What if I changed one Min to a Max? Could I destroy record integrity if I chose to?

Thanks, Donovan

Answer 1

You aren't actually altering data in that query, you are only SELECTing or viewing it.

Unless you do an UPDATE, INSERT, or DELETE or call a stored proc you won't alter the data.

Answer 2

I'm not sure what you mean by destroying record integrity, but there is nothing wrong with calling MIN or MAX functions. This is a very common sort of query.

You should not assume that all the values in a row in your result set will come from the same row in the original table. The values can come from different rows. For example, if the data in your table is this:

account  phone  chargeid locationid
123      456    10       30
123      456    40       20

Then the result will be this:

account  phone  MIN(chargeid) MIN(locationid)
123      456    10            20

The "10" comes from the first row and the "20" comes from the second row.

Also, your usage of MIN on phone seems unnecessary. You should just select this field as it is part of the group by:

SELECT account, phone, MIN(chargeid), MIN(locationid)
FROM import1
GROUP BY account, phone

Answer 3

I Believe his question is that if the following data were present

Account Phone       ChargeId LocationId
1       111-1111    6         8
2       111-1111    7         7
2       111-1111    8         6

would it return 2, 111-1111, 7, 6 (the 7 from chargeId(2) and the 6 from LocationId(3)).

If that is what you're asking, then yes. It'll ruin your results.