Mysql查询返回0个结果

Question

鉴于这两行中的值，为什么我的查询返回 0 行以及如何重写查询才能正常工作？

meta_id post_id meta_key   meta_value
   1422      73 wpcf-milk      22
   1423      73 wpcf-mw        -7

SQL 查询:

   SELECT * FROM wp_postmeta
    WHERE post_id = 73 
    AND ( meta_key = 'wpcf-mw' AND meta_value BETWEEN -8 AND 200 )
    AND ( meta_key = 'wpcf-milk' AND meta_value BETWEEN 20 AND 200 )

Answer 1

SELECT * FROM wp_postmeta 
WHERE post_id = 73 
  AND (( meta_key = 'wpcf-mw' AND meta_value BETWEEN -8 AND 200 ) 
  **OR** ( meta_key = 'wpcf-milk' AND meta_value BETWEEN 20 AND 200 ))

用 OR 改变 AND。