使用来自MySQL数据库PHP的计数填充列表

Question

I am trying to create a list based off of results selected with a wildcard from a column in a MySQL database. I am able to do it, however it seems very slow, and probably the wrong way. Here is the code I am tinkering with now

$optarr = array("leather", "cruise", "tint", "sunroof", "moonroof", "navigation", "antilock");
 foreach ($optarr as $i) {
    $refquery = "SELECT stock, COUNT(stock) FROM vehicle_list AND options LIKE '%$i%'"; 
    $refresult = mysql_query($refquery) or die(mysql_error());
    $row = mysql_fetch_array($refresult);

    if ($row['COUNT(stock)'] != '0') {
    echo "".ucfirst($i)." (".$row['COUNT(stock)'].")<br />";
    }
}

This will output the following

Leather(234)
Cruise(343)
Tint(231)
Sunroof(343)
.....

This list will eventually be around 20-30 different filter options, right now at 4-5 I can see a substantial delay. I'm doing something wrong, Just don't know what. Maybe the entire approach?

The options column in the Database is an entire block of text separated by @ symbols so I am using the Like wildcard to extract vehicle options.

Thanks!

Answer 1

Make the database call prior to the foreach loop. This is calling the database on each loop and will be slow as expected.

Answer 2

From a normalization and optimization perspective your should place your options in a separate table and then use a table to link the vehicle_list table to your options.

This would allow you to use a join and a group by to get your required result using only one query instead of a load of queries using a double sided like (which is not a good idea even when using indexes).

http://dev.mysql.com/doc/refman/5.0/en/group-by-modifiers.html

Answer 3

You have to join tables

 $optarr = array("leather", "cruise", "tint", "sunroof", "moonroof", "navigation", "antilock");
     foreach ($optarr as $i) {
    $refquery = "SELECT stock, COUNT(stock)  FROM vehicle_list 
    LEFT JOIN options ON vehicle_list.stock=options.stock LIKE '%$i%'"; 
    $refresult = mysql_query($refquery) or die(mysql_error());
    $row = mysql_fetch_array($refresult);

    if ($row['COUNT(stock)'] != '0') {
    echo "".ucfirst($i)." (".$row['COUNT(stock)'].")<br />";
    }

Answer 4

It seems you are firing a new query for every time present in the $optarr

You can try creating a list of conditions first and then fire a single query

Something like

$optarr = array("leather", "cruise", "tint", "sunroof", "moonroof", "navigation", "antilock");
 $strCondition = NULL;
 foreach ($optarr as $i) {
    $strCondition .= ( true == is_null(strCondition ) )? "LIKE '%$i%'" : "OR LIKE '%$i%'"; 
}

if( false != $strCondition ) {
    $refresult = mysql_query( 'SELECT stock, COUNT(stock) FROM vehicle_list AND options ' . $strCondition ) or die(mysql_error());
     while( $row = mysql_fetch_array($refresult) )
     {
         if ($row['COUNT(stock)'] != '0') {
         echo "".ucfirst($i)." (".$row['COUNT(stock)'].")<br />";
     }
}

There could be some syntax errors as I haven't test it :p.

The above method would give a performance gain , in general, you should store values within tables in the way you wish to retrieve them (I would recommend adding a new column condition only values like 'leather', cruise' ..etc)

Answer 5

You should probably normalize your options such that they are in a table related to the vehicle_list table. This will make your life much easier going forward.

So say you had a table vehicle_options like this

vehicle_option_id -> primary_key, autoincrement
vehicle_id -> foreign key to vehicle_list table
option -> text string describing option

All three fields would need an index.

You could then get your count from a single query against this table. You don't even need to query vehicle_list at all in this case.

SELECT option, COUNT (vehicle_option_id) AS `option_count` FROM
vehicle_options
GROUP BY option

To normalize further, you might even consider having yet another table options that actually contains the description of the available options and having the vehicle_options table simple act as a many-to-many join table. With this schema your tables would look like this:

vehicle_options

vehicle_id -> foreign key to vehicle_list table
option_id -> foreign key to option table

You would have a primary key across both fields

options

option_id -> primary_key, autoincrement
option -> text string describing option

You would want an index on option if you are going to use it for grouping/sorting purposes

Your query would then look like this:

SELECT o.option AS `option`, COUNT (vo.option_id) AS `option_count`
FROM vehicle_options AS vo
INNER JOIN options AS o
GROUP BY `option`