PHP Query Call Issue - php

Question

I have two tables in my database:
1) blog_table
2) content
In blog_table I have values called postID that may or may not match up to values called id in the table content. I am wanting to know how I can write a while loop or foreach loop that will cycle through content table and perform one action if the id equals the value of postID in the blog_table and perform a different action if it doesn't.
Right now I can only get id = postID
$blog_table = $_REQUEST['blog_table'];
$getblogtable = mysql_query("SELECT * FROM content WHERE type = '5' AND blogID = '{$_REQUEST['id']}' ORDER BY `order` ASC");
while ($row = mysql_fetch_assoc($getblogtable))
{
$getblogposts1 = mysql_query("SELECT postID FROM `$blog_table`");
while ($row1 = mysql_fetch_assoc($getblogposts1))
{
if( $row1['postID'] == $row['id']) {
echo "do something<br>";
}else{
echo "do something else<br>";
}
} echo "<p></p>";
}

Answer 1

[Edit based on OP's comments and revised question]
$getblogposts = mysql_query("SELECT * FROM content WHERE type = '5' AND blogID = '{$_REQUEST['id']}' ORDER BY `order` ASC");
while ($row = mysql_fetch_assoc($getblogposts))
{
$matches = mysql_query("SELECT * FROM $blog_table WHERE postID = $row['id']");
if (mysql_num_rows($matches) > 0)
{
// do something
}
else
{
// do something else
}
}
Regarding a different design, I can't say for sure that it's necessary, but I don't like running a loop of queries like this. I think one query should be enough to get everything you need in this case. Maybe if you describe your application, we could find a better query or more appropriate design.

Answer 2

Just providing an easier to see solution for you to your problem.
I suggest using inner joins which will solve the issue at hand.
For example, Something like:
SELECT * FROM content AS C INNER JOIN $blog_table AS B on B.postID = C.id
Here is a great introduction to joins (inner, left, right, full):
http://www.w3schools.com/sql/sql_join.asp

Answer 3

$blog_table = $_REQUEST['blog_table'];
$getblogtable = mysql_query("SELECT postID FROM `$blog_table`");
while ($row = mysql_fetch_assoc($getblogtable))
{
$postID = $row['postID'];
$getblogposts1 = mysql_query("SELECT * FROM content WHERE id = '$postID' ORDER BY `order` ASC");
while ($row1 = mysql_fetch_assoc($getblogposts1))
{
// if( $row1[id] == $postId )
// do something
// else
// do something else
}
}