Create SQL statement in PHP function using an Array - php

Question

I am creating a PHP function that will take some values, one of which is an array, that I need to use in a MySQL query.
I am creating the array as follows:
$newsArray = createArticleArray(array(2,20,3),5);
Then the function looks something like this (cut down for readability)
function createArticleArray($sectionArray = array(1),$itemsToShow)
{
$SQL = "
SELECT
*
FROM
tbl_section
WHERE
(tbl_section.fld_section_uid = 2 OR tbl_section.fld_section_uid = 20 OR tbl_section.fld_section_uid = 3)
ORDER BY
tbl_article.fld_date_created DESC LIMIT 0,$itemsToShow";
}
The section tbl_section.fld_section_uid = 2 OR tbl_section.fld_section_uid = 20 OR tbl_section.fld_section_uid = 3 is where I need to use the array values.
Basically I need to loop through the values in the array making up that part of the query, however I am having a little problem on how to show or not show the "OR" bits of it as there might be only 1 value or as many as I need.
I was thinking of something like this:
foreach($sectionArray as $section)
{
$sqlString = $sqlString . "tbl_section.fld_section_uid = $section OR";
}
but I don't know how to work out if to put the "OR" in there.

Answer 1

Use implode.
$conditionParts = array();
foreach($sectionArray as $section){
$conditionParts[] = "tbl_section.fld_section_uid = $section";
}
$sqlString .= implode(' OR ', $conditionParts);
This solution answers your question and show you how to use the implode function, but for your specific case you should really use the IN operator.
$sqlString .= "tbl_section.fld_section_uid IN(".implode(',', $sectionArray).")";

Answer 2

One solution is to put an extraneous 0 at the end to consume the final "OR" without any effect. The query parser will just remove it: A OR B OR C OR 0 is turned into A OR B OR C.
Another solution is to use implode to insert the OR:
$sqlString = "tbl_section.fld_section = "
. implode($sectionArray," OR tbl_section.fld_section_uid = ");
Of course, the correct solution is just to use IN:
"WHERE tbl_section.fld_section_uid IN(".implode($sectionArray,',').")";

Answer 3

The query can be made simpler and easier to generate if you use WHERE <column> IN (value1,value2,...) syntax.
Use PHP's implode to produce the (value1,value2,...) part:
$SQL .= ' WHERE tbl_section.fld_section_uid IN (' . implode(',', $array) . ') ';
Yields something like this:
SELECT
...
WHERE tbl_section.fld_section_uid IN (2,20,3)
...

Answer 4

Use PDO's prepare method: http://uk3.php.net/manual/en/pdo.prepare.php
$statement = $pdo->prepare("
SELECT
*
FROM
tbl_section
WHERE
(tbl_section.fld_section_uid = ? OR tbl_section.fld_section_uid = ? OR tbl_section.fld_section_uid = ?)
ORDER BY
tbl_article.fld_date_created DESC LIMIT 0,$itemsToShow");
$statement->execute( $sectionArray );

Answer 5

function createArticleArray($sectionArray = array(), $itemsToShow) {
$conditions = array();
for ($i = 0, $s = count($sectionArray); $i < $s; ++$i) {
$conditions[] = 'tbl_section.fld_section_uid = ' . (int) $sectionArray[$i];
}
$SQL = 'SELECT * FROM tbl_section WHERE ' . implode(' OR ', $conditions) . ' ORDER BY tbl_article.fld_date_created DESC LIMIT 0, ' . (int) $itemsToShow;
}