need help in search [closed] - php

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Closed 9 years ago.
As per my system i need to search brand based on category and subcategory.
Brand table like this
id brandname categoryid subcategoryid
1 xys 1,2,3 1,5,6
Now when i search i select category then as per category all subcategory come now i select subcategory now need to show all the brand based on that category and subcategory.
My brand table look like this because same brand have multiple category and subcategory.Please help me to solve this problem

Answer 1

Given your database design, you can do that like this:
SELECT * FROM mytable WHERE
FIND_IN_SET('5', categoryid) > 0 AND FIND_IN_SET('3', subcategoryid) > 0;
This will find all items from category 5 and subcategory 3.
SELECT * FROM mytable WHERE
FIND_IN_SET('5', categoryid) > 0 AND (
FIND_IN_SET('3', subcategoryid) > 0
OR
FIND_IN_SET('9', subcategoryid) > 0
);
The above will find items in category 5, subcategories 3 and 9. Of course you can also restrict to items that are in both categories, by using AND instead of OR.
But all this is needlessly expensive. You would do better by having a table for brand names, and other tables for category and subcategory IDs, and links, like this:
// This is an article. Many-to-one relation with brands.
CREATE TABLE articles
(
id integer primary key not null auto_increment,
name varchar(...),
brand_id integer,
//, other data
);
CREATE TABLE brands
(
id integer primary key not null auto_increment,
name varchar(...)
//, other data
);
// Categories. Many-to-Many relationship with articles.
CREATE TABLE categories
(
id integer primary key not null auto_increment,
name varchar(...)
//, other data
);
// Subcategories. These are independent from categories, which
// may be right or wrong, depending. Being independent, we do not
// store here parent_category_id.
CREATE TABLE subcategories
(
id integer primary key not null auto_increment,
name varchar(...)
//, other data
);
// Many to many relationship between articles and categories
CREATE TABLE mtm_article_in_category
(
article_id integer not null,
category_id integer not null
);
CREATE TABLE mtm_article_in_subcategory
(
article_id integer not null,
subcategory_id integer not null
);
// Add article 5 to categories 25, 37 and 119:
INSERT IGNORE INTO mtm_article_in_category VALUES ( 5, 25 ), ( 5, 37 ), ( 5, 119 );
// Remove article 18 from subcategory 92
DELETE FROM mtm_article_in_category WHERE article_id = 18 AND subcategory_id = 92;
This way you can run much faster queries, and not have problems such as the inability to assign an article to more than "so many" categories (e.g. 50); nor the headaches if you wanted to move an article from a category to another, that with your current design would be next to impossible.
My search like this at first i chose category the all the subcategory
come based on category.Then when i chose subcategory all the brand
based on that category and subcategory come.Now i add one brand name
one time with multiple category and multiple subcategory.
I have to say, "Oh my God". To be able to "select all the subcategories" /now/, you would have to transform this
category subcategory
4,5 1,7,9,19
5 7,9,11
in
5 1
5 7
5 9
5 19
5 7
5 9
5 11
then run a DISTINCT, and finally use the subcategories as an INNER JOIN based on FIND_IN_SET.
The first step ("explode" a CSV row) can be done like this: http://www.marcogoncalves.com/2011/03/mysql-split-column-string-into-rows/ ... and as you can see it is all but trivial.
I expect that currently you are doing the splitting in PHP.
After doing that, the INNER JOIN is awfully expensive.
We are throwing good money after bad. Your current database design does not allow to do what you want, easily. The simplest way would be:
// My search like this at first i chose category the all the subcategory
// come based on category.
$query = "SELECT subcategoryid FROM mytable WHERE FIND_IN_SET(:mycategory, categoryid) > 0;";
// and run the query.
$subcategories = array();
while($tuple = sql_fetch_tuple($exec))
{
// Explode "1,2,3" into array {1, 2, 3}. Merge into subcategories removing
// duplicates. Rinse. Repeat.
$subcategories = array_unique(array_merge($subcategories, explode(',', $tuple['subcategoryid'])));
}
sql_free($exec);
// Now we have an array of subcategories.
// Then when i chose subcategory all the brand
// based on that category and subcategory come.
$subcat_query = array();
foreach($subcategories as $subcategory)
$subcat_query[] = "FIND_IN_SET('$subcategory', subcategoryid)";
$subcat_query_sql = implode(' OR ', $subcat_query);
$query = "SELECT DISTINCT brand FROM mytable WHERE FIND_IN_SET(:cat, categoryid) AND ( $subcat_query_sql );";
// And here we get all brands. It is wise to save $subcat_query_sql in _SESSION.
// Next search will be:
// >Now i add one brand name
// > one time with multiple category and multiple subcategory.
// Note that you've subtly moved the target once more, now the 'category' has become "multiple".
$brands_arr[] = array();
foreach($brands as $brand)
$brands_arr[] = "'" . sql_escape($brand) . "'";
$brands_sql = implode(',', $brands_arr);
// The cost of this $query is estimated as a significant percentage of U.S. gross internal product, so it ought to be cleared with the FED.
$query = "SELECT * FROM mytable WHERE brand IN ($brands_sql) AND FIND_IN_SET(:cat, categoryid) AND ( $subcat_query_sql );";
It is also possible that the above query will return nothing at all. Suppose that you looked for subcategory 5 and category 12. By your request, getting "all subcategories" and "all categories" might return also brand 6 and subcategory 9. Then these two rows come out,
Marlboro 5 12
Lucky 6 9
and the user selects "Marlboro 6 12". He won't get anything - no rows will match that query.
I am afraid that the user interface and workflow/use case needs looking into, too.