comparing arrays

ging8

I am looking for some help, I am relitivley new to PHP, and what i need to do is this:

I have two sql statments pulling information from a database

(part numbers and their amounts from a database for a given higher level part) so when some one is putting a higherlevel part together they can see what parts and how many of that part go into making that higher level part.
A second Higher level part that is very similar and i am pulling all the same information out of database.

What I need to do now is to either show the parts and their amount that are the same between the two higher level parts or show the differences of the two.

I tried to do this and got lost. I started to use an array

I picture it being done with two arrays and then comparing those arrays and either outputing the same part numbers with the same amount or outputint the part numbers that different amounts.

These higher level parts do not necessarley have all the same parts included. higher level part A could use more parts then higher level part B and vise versa.

Any help would be appriciated

devinemke

spool the two queries into two arrays using the part numbers as the keys and the amounts as the values. then use [man]array_diff[/man] to see which parts are unique.

ging8

that kinda works except

part a might be in both higher level parts but only 3 parts in one and 5 in the other, so that would be different

saraadmin

If you want to find the intersection of arrays you can use the PHP functions array_intersect_*. See array_intersect, array_intersect_uassoc.

However, if you want to post a description of your database table(s) we may be able to work out a query which will select the rows you want. (Hint: try a JOIN on the part names possibly using the LIKE comparison operator.)

ging8

all the records are in one table called BOM(bill of materials) there is a field called OEM which is the higher level part, part_number, and amount.

In this table there are thousands of parts which are linked to a oem in the same table, Part A could be listed several times for different OEM's. and have different amounts

saraadmin

I'm not sure I fully understand your database schema, but assuming your table structure is this:

bom(oem, part_name, amount)

You already know that you can select all the parts for one OEM using:

SELECT * FROM bom WHERE oem="name";

and that you can select all the parts for multiple OEMs by adding all the names to the WHERE clause using OR logic:

SELECT * FROM bom WHERE (oem="name1") OR (oem="name2") etc.;

The easiest way to select all the parts that are in "oem1" but not in "oem2" is probably to use arrays like you said.

Assuming MySQL:

$oem1_query = mysql_query("SELECT part_name, amount FROM bom WHERE oem=\"oem1\"");
$oem1 = array();
while ($row = mysql_fetch_assoc($oem1_query)) { $oem1[] = $row; }

$oem2_query = mysql_query("SELECT part_name, amount FROM bom WHERE oem=\"oem2\"");
$oem2 = array();
while ($row = mysql_fetch_assoc($oem2_query)) { $oem2[] = $row; }

$parts_in_oem1_and_not_oem2 = array_diff($oem1, $oem2);

But I may have misunderstood what you're trying to achieve.

ging8

sorry it took so long for me to get back, thanks for the quick response, I also need to show when the amounts are different

ging8

i just noticed now that your code is accessing a mysql database, I am using an Access DB