on子句中的未知列{0}

小编典典

on子句中的未知列{0}

sql

我在MySQL数据库上做一些工作，完全收到错误时陷入困境

1054 - Unknown column 'Puzzles.PuzzleID' in 'on clause'

表名和列名都存在并且正确。我刚刚在Navicat的视觉设计师中创建了它。

SELECT
`PuzzleCategories`.`PuzzleCategory`,
`Clients`.`BusinessName`,
`Puzzles`.`PuzzleNumber`
FROM
`Puzzles`
Inner Join `PuzzleCategories` ON `Puzzles`.`PuzzleCategoryID` = `PuzzleCategories`.`PuzzleCategoryID` ,
`Clients`
Inner Join `Publications` ON `Clients`.`ClientID` = `Publications`.`ClientID`
Inner Join `PublicationIssues` ON `PublicationIssues`.`PublicationID` =     `Publications`.`PublicationID`
Inner Join `PuzzleUsages` ON `PuzzleUsages`.`PuzzleID` = `Puzzles`.`PuzzleID` AND `PuzzleUsages`.`PublicationIssueID` = `PublicationIssues`.`PublicationIssueID`

阅读 217

2021-05-16

共1个答案

小编典典

如果您确定列名正确，那么问题可能出在连接顺序上。听起来逗号的每一侧的连接都是单独构建的。（我不确定这是否可能，但是这是我根据您提供的信息做出的唯一猜测）

该查询可以重组为：

SELECT
`PuzzleCategories`.`PuzzleCategory`,
`Clients`.`BusinessName`,
`Puzzles`.`PuzzleNumber`
FROM
`Clients`
INNER JOIN `Publications` ON `Clients`.`ClientID` = `Publications`.`ClientID`
INNER JOIN `PublicationIssues` ON `PublicationIssues`.`PublicationID` =   `Publications`.`PublicationID`
INNER JOIN `PuzzleUsages` ON`PuzzleUsages`.`PublicationIssueID` = `PublicationIssues`.`PublicationIssueID`
INNER JOIN `Puzzles` ON `Puzzles`.`PuzzleID` = `PuzzleUsages`.`PuzzleID`
INNER JOIN `PuzzleCategories` ON `Puzzles`.`PuzzleCategoryID` = `PuzzleCategories`.`PuzzleCategoryID`

反正读起来更好。

2021-05-16