SQL返回重複結果

Question

我正在爲WordPress編寫一個SQL查詢，用於搜索用戶搜索之間的活動事件。我現在正在對它進行硬編碼測試。

目前，每當post_id出現在wp_postmeta表中時，都會返回兩個事件，任何人都可以看到哪裏可能存在這個邏輯的問題？

SELECT ID, post_title 
    FROM $wpdb->posts AS post 
    INNER JOIN $wpdb->postmeta AS meta 
    ON (post.ID = meta.post_id) 
    INNER JOIN $wpdb->postmeta AS meta2 
    ON (post.ID = meta2.post_id) 
    WHERE post.post_status = 'publish' 
    AND post.post_type = 'event' 
    AND post.post_author = '1' 
    AND (
      ((meta.meta_key = 'date_0_start-date' AND meta.meta_value < '20140620') AND (meta2.meta_key = 'date_0_end-date' AND meta2.meta_value > '20140630')) 
     OR ((meta.meta_key = 'date_0_start-date' AND meta.meta_value < '20140620') AND (meta2.meta_key = 'date_0_end-date' AND meta2.meta_value >= '20140620')) 
     OR ((meta.meta_key = 'date_0_start-date' AND meta.meta_value > '20140620') AND (meta.meta_key = 'date_0_start-date' AND meta.meta_value <= '20140630')) 
     OR ((meta.meta_key = 'date_0_start-date' AND meta.meta_value >= '20140620') AND (meta2.meta_key = 'date_0_end-date' AND meta2.meta_value <= '20140630')) 
    ) 

Answer 1

你必須使用DISTINCT像

SELECT DISTINCT ID, post_title

，而不是

SELECT ID, post_title

Answer 2

如果我理解正確的問題，我想你需要的最後一個括號部分where clause to look like this

meta.meta_key = 'date_0_start-date' AND meta.meta_value <= '20140630' and 
meta2.meta_key = 'date_0_end-date' AND meta2.meta_value >= '20140620' 

這應該與重疊的日期範圍「20140620」的任何事件爲「20140630」