foreach loop, assistance request

Posted on 16th Feb 2014 07:03 pm by admin

I would like some guidance on the usage of foreach as I try to parse through a large database and whittle down to a few select stocks. I'm currently doing this with vb, but I'm wanting to get it working in php. I think I'm just struggling with the syntax, but I'm unsure. After a week of trial and error, I've decided it's time to reach out for help.

Currently, I can connect with the db, run a simple query, and return the results to a web page. The db is made up of the past 2 weeks' stock symbols, prices, volumes. I want to go through each symbol and check against 2 conditions. If both conditions are true for that symbol, I want to put it (and the 2 weeks of data) in another db for further parsing later. So in plain english, here's what I'm trying to accomplish:

for each unique symbol,
if condition a is true on every day and
condition b is true on every day, then
write all the data for the past 2 weeks for that symbol to db_x

I'm not sure if it's the most efficient method, but I was thinking I'd loop through the db checking the conditions and meanwhile saving the data to an array, then if the conditions are true when it gets to a different symbol it runs thrrough the array and adds the data to db_x....if it gets a false anywhere along the way for a particular symbol, it clears the array and moves on to the next symbol to check it. I don't want to hard code the 2 week's (ie loop through each stock 10 times, because of holidays, some stocks do not trade every day, etc). I need to check for the symbol changing to know when it's time to make a decision on whether to add or drop the previous symbol.

I've got it loosely structured to use a while loop to cycle through the entire list:
while ($row = mysql_fetch_assoc($result)) {

Then I suppose the foreach would be used, but I'm running into complex commands that I'm needing guidance on. Is ArrayIterator current to PHP5, and if so, is this the direction I should be studying up on? Any recommendations on a good online tutorial for someone who is not well versed in programming, but can get by through dogged determination (and a little help from my friends )?

It should be noted that my array I'm iterating through (the symbols) has several associated elements (volume, closing price, high, low).

As for providing code, I really don't have anything to go by yet. I have not delved too far past "foreach ($arr as $key => $value). I'm using mysql 5 and php 5 and apache2 on an Ubuntu 9.04 machine.

Thank you,

Your Answer:

Login to answer

Other forums

split values
I have values that are returned to me in this format:

name=>test,age=>49

selection tool on raster image
Hi!
I have to implement in my app a selection tool which lets users to select region of any shape

Socket programming
Hello all,

I have a PHP socket script. GPS trackers connect to this socket. IMEI verification

Pro-rata Billing in Periodic Billing for Rental
Hi guys,

We have a situation, where a rental contract starts at the mid of the month say

mySQL and PHP search
Hello,
I am trying to code a project and ran into a brick wall with one of my pages. I am pretty

php or sql?
Sorry not sure if this is a sql problem or php the following code is supposed to delete data from th

adding 0 to numbers
Hey guys i need to create a 00001 number in a loop. Is there a better way of forcing a 5 digit numbe

question about stripslashes and real_escape_string
im cleaning up an old app that I wrote fixing some of the vulernabilities from attacks.

I hav

Help pulling in 'id' with "read more" link
I'm trying to create snippets of my articles in the cms I'm creating, and then have them redirect to

How to add functionality to a simple php calender?
Hello everyone,

I have just finished creating a simple php calander. Can someone point