SQL 查询、JOIN 和 CASE 语句给出错误

Question

在我添加 JOIN 和 WHERE 语句之前，我的查询一直有效。我需要从另一个表中加入 id，这样我就可以只过滤我想要的行。有什么建议吗？感谢您的帮助。

错误：#1066 - 不是唯一的表/别名：'ahv9t_facileforms_subrecords'

     SELECT
record,
MAX(CASE WHEN title = 'Listing ID' then value END) AS Listing,
MAX(CASE WHEN title = 'Status' then value END) AS Status,
MAX(CASE WHEN title = 'Resort' then value END) AS Resort,
MAX(CASE WHEN title = 'Points on Deed' then value END) AS Points,
MAX(CASE WHEN title = 'Use Year' then value END) AS UseYear,
MAX(CASE WHEN title = 'Points on Deed' then value END) AS Points,
MAX(CASE WHEN title = 'Last Years Points' then value END) AS LastYearPoints,
MAX(CASE WHEN title = 'This Years Points' then value END) AS ThisYearPoints,
MAX(CASE WHEN title = 'Next Years Points' then value END) AS NextYearPoints,
MAX(CASE WHEN title = 'Points Available' then value END) AS PointsAvailable,
MAX(CASE WHEN title = 'Price Per Point' then value END) AS PricePerPoint,
MAX(CASE WHEN title = 'Price' then value END) AS Price,
MAX(CASE WHEN title = 'Closing Cost' then value END) AS ClosingCost,
MAX(CASE WHEN title = 'Annual Dues at Closing' then value END) AS AnnualDuesAtClosing,
MAX(CASE WHEN title = 'Total Cost' then value END) AS TotalCost,
MAX(CASE WHEN title = 'Direct Price Per Point' then value END) AS DirectPricePerPoint,
MAX(CASE WHEN title = 'Savings' then value END) AS Savings,
MAX(CASE WHEN title = 'Contract Expires' then value END) AS ContractExpires,
MAX(CASE WHEN title = 'Current Annual Fees' then value END) AS CurrentAnnualFees
FROM ahv9t_facileforms_subrecords
JOIN ahv9t_facileforms_subrecords ON ahv9t_facileforms_records.id = ahv9t_facileforms_subrecords.record
WHERE ahv9t_facileforms_records.form = '12'
GROUP BY record

Answer 1

所以在我修复了 JOIN 部分之后。它给了我一个列“标题”是模棱两可的错误。所以我在“title=”前面为我的每一列/行添加了表名。那解决了它。现在我得到了我所追求的。

SELECT
record,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Listing ID' then value END) AS Listing,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Status' then value END) AS Status,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Resort' then value END) AS Resort,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Points on Deed' then value END) AS Points,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Use Year' then value END) AS UseYear,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Points on Deed' then value END) AS Points,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Last Years Points' then value END) AS LastYearPoints,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'This Years Points' then value END) AS ThisYearPoints,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Next Years Points' then value END) AS NextYearPoints,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Points Available' then value END) AS PointsAvailable,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Price Per Point' then value END) AS PricePerPoint,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Price' then value END) AS Price,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Closing Cost' then value END) AS ClosingCost,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Annual Dues at Closing' then value END) AS AnnualDuesAtClosing,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Total Cost' then value END) AS TotalCost,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Direct Price Per Point' then value END) AS DirectPricePerPoint,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Savings' then value END) AS Savings,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Contract Expires' then value END) AS ContractExpires,
MAX(CASE WHEN ahv9t_facileforms_subrecords.title = 'Current Annual Fees' then value END) AS CurrentAnnualFees
FROM ahv9t_facileforms_subrecords
JOIN ahv9t_facileforms_records ON ahv9t_facileforms_records.id = ahv9t_facileforms_subrecords.record
WHERE ahv9t_facileforms_records.form = '12'
GROUP BY record

Answer 2

请使用别名和每个表名来区分表调用：

FROM ahv9t_facileforms_subrecords 作为 A

加入 ahv9t_facileforms_records 作为 B ON B.ahv9t_facileforms_records.id = A.ahv9t_facileforms_subrecords.record

WHERE A.ahv9t_facileforms_records.form = '12' 按记录分组

Answer 3

因为您的查询缺少正确限定的列名，所以不清楚它到底在做什么。也就是说，我认为您正在尝试这样做：

SELECT ffs.record,
       MAX(CASE WHEN ffs2.title = 'Listing ID' then ffs2.value END) AS Listing,
       MAX(CASE WHEN ffs2.title = 'Status' then ffs2.value END) AS Status,
       MAX(CASE WHEN ffs2.title = 'Resort' then ffs2.value END) AS Resort,
       MAX(CASE WHEN ffs2.title = 'Points on Deed' then ffs2.value END) AS Points,
       MAX(CASE WHEN ffs2.title = 'Use Year' then ffs2.value END) AS UseYear,
       MAX(CASE WHEN ffs2.title = 'Points on Deed' then ffs2.value END) AS Points,
       MAX(CASE WHEN ffs2.title = 'Last Years Points' then ffs2.value END) AS LastYearPoints,
       MAX(CASE WHEN ffs2.title = 'This Years Points' then ffs2.value END) AS ThisYearPoints,
       MAX(CASE WHEN ffs2.title = 'Next Years Points' then ffs2.value END) AS NextYearPoints,
       MAX(CASE WHEN ffs2.title = 'Points Available' then ffs2.value END) AS PointsAvailable,
       MAX(CASE WHEN ffs2.title = 'Price Per Point' then ffs2.value END) AS PricePerPoint,
       MAX(CASE WHEN ffs2.title = 'Price' then ffs2.value END) AS Price,
       MAX(CASE WHEN ffs2.title = 'Closing Cost' then ffs2.value END) AS ClosingCost,
       MAX(CASE WHEN ffs2.title = 'Annual Dues at Closing' then ffs2.value END) AS AnnualDuesAtClosing,
       MAX(CASE WHEN ffs2.title = 'Total Cost' then ffs2.value END) AS TotalCost,
       MAX(CASE WHEN ffs2.title = 'Direct Price Per Point' then ffs2.value END) AS DirectPricePerPoint,
       MAX(CASE WHEN ffs2.title = 'Savings' then ffs2.value END) AS Savings,
       MAX(CASE WHEN ffs2.title = 'Contract Expires' then ffs2.value END) AS ContractExpires,
       MAX(CASE WHEN ffs2.title = 'Current Annual Fees' then ffs2.value END) AS CurrentAnnualFees
FROM ahv9t_facileforms_subrecords ffs JOIN
     ahv9t_facileforms_subrecords ffs2
     ON ffs.id = ffs2.record
WHERE ffs.form = '12'
GROUP BY ffs.record;

一般来说，您应该限定所有列名。

也就是说，我认为你可以在没有自我加入的情况下完成任何你想做的事情。但是您还没有解释那是什么，因此很难提供更多建议。我建议您提出一个新的问题，其中包含一组简化的数据和对您想要完成的目标的清晰解释。