merge two tables

[zeberrun]

hello,

in 1. stage i select the name of products_id from table and write it to meta tag.

in 2. stage i select the name of category id of same product and write to meta tag.
in 3. stage i write the result
also it is not written all the lines, the code calls store name, description if index, contact_us and information pages.

my problem is
i can not merge two tables in one command. i mean i want to add meta tags, product_name | category name | if determined manufacturers name

if i could do it would be

$meta_title_tag= $product_meta['products_name'] . ' | ' . $category_name 'products_name'] ;

i can not merge two tables in one command. i mean i want to add

rgds

1.
if (basename($PHP_SELF) == FILENAME_DEFAULT) {
if (isset($HTTP_GET_VARS['products_id'])){
$product_meta_query = tep_db_query("select products_name, products_description from " . TABLE_PRODUCTS_DESCRIPTION . " where products_id = '" . (int)$HTTP_GET_VARS['products_id'] . "' and language_id = '" . (int)$languages_id . "'");
$product_meta = tep_db_fetch_array($product_meta_query);
$meta_title_tag = $product_meta['products_name'];

2.
//meta category
if ((isset($_GET['cPath'])) && (!isset($HTTP_GET_VARS['products_id']))) {
$category_name_query = tep_db_query("select cd.categories_name from " . TABLE_CATEGORIES . " c, " . TABLE_CATEGORIES_DESCRIPTION . " cd where c.categories_id = '" . (int)$current_category_id . "' and cd.categories_id = '" . (int)$current_category_id . "' and cd.language_id = '" . (int)$languages_id . "'");
$category_name = tep_db_fetch_array($category_name_query);

..........
}
3.
echo '<title>' . $meta_title_tag . '</title>' . "\n";
echo '<meta name="description" content="' . $meta_description_tag . '" />' . "\n";
echo '<meta name="keywords" content="' . $meta_keywords_tag . '" />' . "\n";

[dalecosp]

Please wrap your code in

tags for legibility.

You can certainly utilize more than one table in a query. This is known as a JOIN; there are several types, Left, Right, Inner, Outer, etc. The main thing to remember is that you need to carefully restrict JOIN statements in order to avoid a Cartesian product (that is, you end up select a temporary table that is the size of table A TIMES table B --- not at all a Good Thing(tm)).

The standard rule of thumb is that there should be (N-1) join predicates, where "N" is the number of tables involved in the join.

Here's a query I wrote today with a simple "comma" (Inner) JOIN:

select cd.id,c.name from clientdata as cd,clients as c where cd.id=c.id and cd.code=21 and c.biztype=5;

From this, I get a nice table result of two columns from two different tables. I avoid the Cartesian join with the first part of the WHERE clause.

HTH,

[dalecosp]

And if you're saying that this fails:

"select cd.categories_name from " . TABLE_CATEGORIES . " c, " . TABLE_CATEGORIES_DESCRIPTION . " cd where c.categories_id = '" . (int)$current_category_id . "' and cd.categories_id = '" . (int)$current_category_id . "' and cd.language_id = '" . (int)$languages_id . "'

... that's because you forgot the "as", I think, hmm?

[bradgrafelman]

dalecosp;10993712 wrote:

that's because you forgot the "as", I think, hmm?

The 'AS' keyword (such as when creating aliases) is optional and, from what I've seen (both in my SQL and in others'), often omitted.