如何添加最小和最大的價格在此查詢

Question

您好人我有這個數據庫體系結構：

table books [id,title,description,date_released] 
 
------------------------------------------------------- 
 
table authors [id,name] 
 
table books_authors[book_id,author_id] 
 
ALTER TABLE `books_authors` 
 
    ADD CONSTRAINT `books_authors_ibfk_1` FOREIGN KEY (`book_id`) REFERENCES `books` (`id`) ON DELETE CASCADE ON UPDATE CASCADE, 
 
    ADD CONSTRAINT `books_authors_ibfk_2` FOREIGN KEY (`author_id`) REFERENCES `authors` (`id`) ON DELETE CASCADE ON UPDATE CASCADE; 
 
-------------------------------------------------------- 
 
table categories [id,name] 
 
table books_authots[book_id,category_id] 
 
ALTER TABLE `books_categories` 
 
    ADD CONSTRAINT `books_categories_ibfk_1` FOREIGN KEY (`book_id`) REFERENCES `books` (`id`) ON DELETE CASCADE ON UPDATE CASCADE, 
 
    ADD CONSTRAINT `books_categories_ibfk_2` FOREIGN KEY (`category_id`) REFERENCES `categories` (`id`) ON DELETE CASCADE ON UPDATE CASCADE; 
 
-------------------------------------------------------- 
 
table books_locations [id,name] 
 
table books_locations [book_id,location_id] 
 
ALTER TABLE `books_locations` 
 
    ADD CONSTRAINT `books_locations_ibfk_1` FOREIGN KEY (`book_id`) REFERENCES `books` (`id`) ON DELETE CASCADE ON UPDATE CASCADE, 
 
    ADD CONSTRAINT `books_locations_ibfk_2` FOREIGN KEY (`location_id`) REFERENCES `locations` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;

查詢是：

$sql = "SELECT DISTINCT bk.title AS Title, YEAR(bk.date_released) AS Year, bk.price AS Price, cat.name AS Category, aut.name AS Author FROM books bk 
 

 
     JOIN books_authors bk_aut 
 
      ON bk_aut.book_id = bk.id 
 

 
     JOIN authors aut 
 
      ON aut.id = bk_aut.author_id 
 

 
     JOIN books_categories bk_cat 
 
      ON bk_cat.book_id = bk.id 
 

 
     JOIN categories cat 
 
      ON cat.id = bk_cat.cat_id 
 
      
 
      JOIN books_locations bk_loc 
 
      ON bk_cat.book_id = bk.id 
 

 
     JOIN locations loc 
 
      ON loc.id = bk_loc.loc_id   
 
"; 
 

 
if (isset($_GET['srch_for'])){ 
 

 
     $locations = array(); 
 
     $getters = array(); 
 
     $queries = array(); 
 

 
     foreach($_GET as $key => $value) { 
 
     $temp = is_array($value) ? $value : intval(trim($value)); 
 
     if (!empty($temp)) { 
 
      list($key) = explode("-",$key); 
 
      if ($key == 'srch_locations'){ 
 
      array_push($locations,$value); 
 
      } 
 
      if (!in_array($key,$getters)){ 
 
      $getters[$key] = intval(trim($value)); 
 
      } 
 
     } 
 
     } 
 

 
     if (!empty($locations)) { 
 
     $loc_qry = implode(",",$locations); 
 
     } 
 

 
     if(!empty($getters)) { 
 

 
     foreach($getters as $key => $value){ 
 
      ${$key} = $value; 
 
      switch($key) { 
 
      case 'srch_for': 
 
      array_push($queries, "(bk.title LIKE '%$srch_for%' || bk.description LIKE '%$srch_for%' || bk.isbn LIKE '%$srch_for%')"); 
 
      
 
      case 'srch_author': 
 
      array_push($queries, "bk_aut.author_id = $srch_author"); 
 
      break; 
 
      case 'srch_language': 
 
      array_push($queries, "bk_cat.cat_id = $srch_category"); 
 
      break; 
 
      case 'srch_locations': 
 
      array_push($queries, "bk_loc.location_id IN ($loc_qry)"); 
 
      break; 
 
      
 
      } 
 
     } 
 
    } 
 
     
 
    if(!empty($queries)) { 
 
     $sql .= " WHERE "; 
 
     $i=1; 
 
     foreach($queries as $query) { 
 
      if ($i < count($queries)) { 
 
       $sql .= $query." AND "; 
 
      }else{ 
 
       $sql .= $query; 
 
      } 
 
      $i++; 
 
     } 
 

 
    } 
 

 
     $sql .= " ORDER BY bk.title ASC"; 
 
    }

我想要t按Min（價格）和Max（價格）對書籍進行排序是否正確？

$sql = "SELECT DISTINCT (bk.title AS Title, YEAR(bk.date_released) AS Year, bk.price AS Price, cat.name AS Category, aut.name AS Author), min(price), max(price) FROM books bk .....";

和其中i由組？ 你可以幫我請謝謝你提前

Answer 1

它看起來像你需要像這樣（沒有distinct需要）：

select 
    bk.title as Title 
    , year(bk.date_released) as Year 
    , pr.price as Price 
    , cat.name as Category 
    , aut.name as Author 
    , min(price) as minPrice 
    , max(price) as maxPrice 
from books bk 
    inner join books_categories bkcat 
    on bk.book_id = bkcat.book_id 
    inner join categories cat 
    on bkcat.cat_id = cat.cat_id 
    inner join books_authors bkaut 
    on bk.book_id = bkaut.book_id 
    inner join authors aut 
    on bkaut.author_id = aut.author_id 
group by 
    bk.title 
    , year(bk.date_released) 
    , pr.price 
    , cat.name 
    , aut.name