如何做從x等於多個值的地方選擇？

所以我'，調試一些代碼，並有以下的SQL查詢（從它真正的簡化）。如何做從x等於多個值的地方選擇？

SELECT ads.*, location.county 
FROM ads 
LEFT JOIN location ON location.county = ads.county_id 
WHERE ads.published = 1 
AND ads.type = 13 
AND ads.county_id = 2 
OR ads.county_id = 5 
OR ads.county_id = 7 
OR ads.county_id = 9

我從查詢中得到了很奇怪的結果，我認爲它是因爲第一個OR否定了AND之前的結果。因此，我將搜索結果反饋給所有類型的廣告，而不僅僅是類型13.每次查詢被調用時，可能會有許多縣需要查找，或者只有幾個縣。

任何幫助正確的方式去這個將不勝感激。

來源

2008-11-04 Binarytales

圍繞「或」 S看跌括號：

SELECT ads.*, location.county 
FROM ads 
LEFT JOIN location ON location.county = ads.county_id 
WHERE ads.published = 1 
AND ads.type = 13 
AND 
(
    ads.county_id = 2 
    OR ads.county_id = 5 
    OR ads.county_id = 7 
    OR ads.county_id = 9 
)

甚至更好，使用IN：

SELECT ads.*, location.county 
FROM ads 
LEFT JOIN location ON location.county = ads.county_id 
WHERE ads.published = 1 
AND ads.type = 13 
AND ads.county_id IN (2, 5, 7, 9)

來源

2008-11-04 12:49:18 Greg

我認爲IN版本更易於閱讀並且不太可能返回意外結果。 – DOK 2008-11-04 12:52:47

您可以嘗試使用周圍或表達式括號，以確保您的查詢的解釋正確，或者更簡潔，使用IN：

SELECT ads.*, location.county 
FROM ads 
LEFT JOIN location ON location.county = ads.county_id 
WHERE ads.published = 1 
AND ads.type = 13 
AND ads.county_id IN (2,5,7,9)

來源

2008-11-04 12:50:43

而且更加容易使用IN：

SELECT ads.*, location.county 
    FROM ads 
    LEFT JOIN location ON location.county = ads.county_id 
    WHERE ads.published = 1 
     AND ads.type = 13 
     AND ads.county_id IN (2,5,7,9)

來源

2008-11-04 12:51:59 Ruben

如何做從x等於多個值的地方選擇？

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