Multiple criteria search with 4 dropdown lists

Question

I want to perform a multiple criteria search on a MySQL
database. Users should be able to use from 4 dropdown lists in a
form only one criterium, all 4 of them or 2 or 3.
Each used dropdown list gives a numeric variable: Fvar1 ...
Fvar4. The variables from the dropdown lists used should be matched
with numeric fields in the database: DBvar1...DBvar4
The numeric variables from the dropdown lists that are not
used, should be ignored.
Example: a user selects a value in dropdown list 2 and 3 and
does not use dropdown lists 1 and 4. Fvar1 and Fvar 4 should then
be ignored for the search, that has to be performed with Fvar2 and
Fvar3, who have to be matched with DBvar2 and DBvar3.
Anyone who can help me out with the WHERE statement in my SQL
query?
Your help will be greatly appreciated.
Erik

Answer 1

Erik61 wrote:
> I want to perform a multiple criteria search on a MySQL
database. Users should
> be able to use from 4 dropdown lists in a form only one
criterium, all 4 of
> them or 2 or 3.
Start by using the Advanced Recordset dialog box to create a
query that
looks for all four variables. Then switch to Code view and
start carving
up the code created by Dreamweaver.
The query will look something like this:
$query_getProducts = sprintf("SELECT product_name, price
FROM products
WHERE prod_type = %s AND colour = %s AND size = %s AND range
= %s
ORDER BY price ASC",
GetSQLValueString($var1_getProducts, "text"),
GetSQLValueString($var2_getProducts, "text"),
GetSQLValueString($var3_getProducts, "text"),
GetSQLValueString($var4_getProducts, "text"));
Change it like this:
$query_getProducts = "SELECT product_name, price
FROM products
WHERE ";
$where = false;
if (!empty($_GET['prod_type')) {
$query_getProducts .= sprintf("prod_type = %s ",
GetSQLValueString($var1_getProducts, "text"));
$where = true;
if (!empty($_GET['colour'])) {
if ($where) {
$query_getProducts .= 'AND ';
$query_getProducts .= sprintf('colour = %s ',
GetSQLValueString($var2_getProducts, "text"));
$where = true;
if (!empty($_GET['size'])) {
if ($where) {
$query_getProducts .= 'AND ';
$query_getProducts .= sprintf('size = %s ',
GetSQLValueString($var3_getProducts, "text"));
$where = true;
if (!empty($_GET['range'])) {
if ($where) {
$query_getProducts .= 'AND ';
$query_getProducts .= sprintf('range = %s',
GetSQLValueString($var4_getProducts, "text"));
That builds the query in stages using $where to decide
whether to add
"AND" in front of the second, third, and fourth variables.
David Powers, Adobe Community Expert
Author, "The Essential Guide to Dreamweaver CS3" (friends of
ED)
Author, "PHP Solutions" (friends of ED)
http://foundationphp.com/