mysql - 这个 MySQL 查询有什么问题 (#1064)？

Question

谁能告诉我这个 MySQL 查询有什么问题

SELECT count(items.id) AS numrows 
FROM items, subcategories 
WHERE items.`base_school` = 'UNN' 
    AND items.subcategory = subcategories.id 
    AND subcategories.parent_category = 3 
JOIN `item_images` 
    ON items.id=`item_images`.`item_id`

它不断抛出这个错误:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'JOIN item_images ON items.id=item_images.item_id' at line 1

Answer 1

你在错误的位置有 WHERE 子句，试试这个:

SELECT count(items.id) AS numrows 
FROM items
INNER JOIN subcategories 
    ON items.subcategory = subcategories.id 
INNER JOIN item_images 
    ON items.id=item_images.item_id
WHERE items.base_school = 'UNN' 
    AND subcategories.parent_category = 3