1 sql database database-design query-optimization
看来我的SQL不是基于的限制结果price.
在我之前的帖子中,SQL:帮助我优化我的SQL,人们表示我应该使用LEFT OUTER JOIN.
SELECT homes.home_id,
address,
city,
state,
zip,
price,
photo_id,
photo_url_dir
FROM homes
LEFT OUTER JOIN home_photos ON homes.home_id = home_photos.home_id
AND primary_photo_group_id = home_photo_group_id
AND home_photo_type_id =2
AND display_status = true
AND homes.price BETWEEN 500000 AND 1000000
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我不明白.当我有一个WHERE条件来精确限制该字段时,为什么上面的SQL会显示价格低于500000的房屋.
谢谢你的帮助.
我希望根据PRICEX和Y之间的标准显示家庭和家庭没有home_photo ...或者SQFTZ.但是这些标准需要应用于那些有和homes没有a的家庭.home_photo
SELECT homes.home_id,
address,
city,
state,
zip,
price,
photo_id,
photo_url_dir
FROM homes
LEFT OUTER JOIN home_photos ON homes.home_id = home_photos.home_id
AND homes.primary_photo_group_id = home_photos.home_photo_group_id
AND home_photos.home_photo_type_id =2
WHERE homes.display_status = true
AND homes.price BETWEEN 500000 AND 1000000
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SQL*_*ace 19
最后一行应该使用WHERE而不是AND
WHERE homes.price BETWEEN 500000 AND 1000000
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最终结果是以下SQL:
SELECT
homes.home_id,
homes.address,
homes.city,
homes.state,
homes.zip,
homes.price,
home_photos.photo_id,
home_photos. photo_url_dir
FROM
homes
LEFT OUTER JOIN home_photos ON
homes.home_id = home_photos.home_id
AND homes.primary_photo_group_id = home_photos.home_photo_group_id
AND home_photos.home_photo_type_id =2
WHERE
homes.price BETWEEN 500000 AND 1000000
AND homes.display_status = true
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编辑
现在你的SQFT将在WHERE之前
AND home_photos.home_photo_type_id =2
AND SQFT <=2000
WHERE homes.price BETWEEN 500000 AND 1000000
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