postgres的：交叉並在查詢

刪除重複我有需要具有其值期間轉換爲列的查詢數據：postgres的：交叉並在查詢

SELECT p.*, CASE WHEN s.stat_id=1 THEN s.base_stat END AS "hp", CASE WHEN s.stat_id=2 THEN s.base_stat END AS "attack", CASE WHEN s.stat_id=3 THEN s.base_stat END AS "defense", CASE WHEN s.stat_id=4 THEN s.base_stat END AS "special_attack", CASE WHEN s.stat_id=5 THEN s.base_stat END AS "special_defense", CASE WHEN s.stat_id=6 THEN s.base_stat END AS "speed" FROM pokemon_stats s INNER JOIN pokemon p on s.pokemon_id=p.id

其中給出：

在表pokemon_stats，對於每個屬性單獨存在一個新行。

如何我可以寫我的查詢，使用交叉表或沒有它，使重複被刪除？

來源

2017-11-11 user1429980

它是MySQL的Postgres的嗎？ –

使用sum（CASE WHEN s.stat_id = 1 THEN s.base_stat END）作爲「hp」，其他列也相似。 –

嗨。爲文本使用文本 - [不要使用圖像/鏈接]（https://meta.stackoverflow.com/q/285551/3404097）。閱讀並執行[mcve]。你有什麼嘗試？ – philipxy

使用crosstab功能：

首先，安裝tablefunc module

CREATE EXTENSION IF NOT EXISTS tablefunc; 

SELECT * 
FROM pokemon p 
JOIN crosstab('SELECT 
        pokemon_id 
       , stat_id 
       , base_stat 
       FROM pokemon_stats 
       WHERE stat_id IN (1,2,3,4,5,6) 
       ORDER BY 1, 2') xtab (id integer 
            , hp integer 
            , attack integer 
            , defense integer 
            , special_attack integer 
            , special_defense integer 
            , speed integer) 
    USING (id)

來源

2017-11-11 20:46:06

試試這個

SELECT p.id, p.identifier, p.species_id, p.height, p.weight, p.base_experience, p.order ,p.is_default, 
sum(CASE WHEN s.stat_id=1 THEN s.base_stat END) AS "hp", 
sum(CASE WHEN s.stat_id=2 THEN s.base_stat END) AS "attack", 
sum(CASE WHEN s.stat_id=3 THEN s.base_stat END) AS "defense", 
sum(CASE WHEN s.stat_id=4 THEN s.base_stat END) AS "special_attack", 
sum(CASE WHEN s.stat_id=5 THEN s.base_stat END) AS "special_defense", 
sum(CASE WHEN s.stat_id=6 THEN s.base_stat END) AS "speed" 
FROM pokemon_stats s 
INNER JOIN pokemon p on s.pokemon_id=p.id 
group by 
p.id, p.identifier, p.species_id, p.height, p.weight, p.base_experience, p.order ,p.is_default

來源

2017-11-11 06:16:09

postgres的：交叉並在查詢

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