+ // Search word fragments.
+ // sfc = search fragment condition
+ $sfc = "( ";
+ // sfr = serach fragment relevation
+ $sfr = "( ";
+ $sep = ' +-*<>()~"';
+ $fragm = strtok($search_query, $sep);
+ while ($fragm !== FALSE)
+ {
+ $sfc .= "(title LIKE '%$fragm%'
+ OR description LIKE '%$fragm%'
+ OR tags LIKE '%$fragm%') OR ";
+
+ // Frament relevations are half of boolean relevations such
+ // that they will appear at the end of the results.
+ $sfr .= "0.25 * (title LIKE '%$fragm%')
+ + 0.1 * (description LIKE '%$fragm%')
+ + 0.15 * (tags LIKE '%$fragm%') + ";
+
+ $fragm = strtok($sep);
+ }
+ $sfc = substr($sfc, 0, -4) . " )";
+ $sfr = substr($sfr, 0, -3) . " )";
+
+ if (! $this->is_advanced_search_query($search_query))
+ {
+ $search_cond = "MATCH (title, description, tags)
+ AGAINST ('$search_query') OR $sfc";
+ $relevance = "( MATCH (title, description, tags)
+ AGAINST ('$search_query') + $sfr ) AS relevance";
+ }
+ // boolean mode
+ else
+ {
+ $against = "AGAINST ('$search_query' IN BOOLEAN MODE)";
+ $search_cond = "( MATCH (title, description, tags)
+ $against) OR $sfc";
+ $relevance = "( 0.5 * (MATCH(title) $against)
+ + 0.3 * (MATCH(tags) $against)
+ + 0.2 * (MATCH(description) $against)
+ + $sfr) AS relevance";
+ }
+
+ if ($count === 0)
+ {
+ $selected_columns = "COUNT(*) count";
+ $order = "";
+ $limit = "";
+ }
+ else
+ {
+ // TODO select data, description if details are needed
+ $selected_columns = "id, name, title, duration, user_id, views,
+ thumbs_count, default_thumb,
+ (views + likes - dislikes) AS score,
+ $relevance";
+ $order = "ORDER BY relevance DESC, score DESC";
+ $limit = "LIMIT $offset, $count";
+ }
+
+ if ($category_id !== NULL)
+ $category_cond = "category_id = '$category_id' AND ";
+ else
+ $category_cond = "";
+
+ $str_query = "SELECT $selected_columns