错误1025 Err 150在MySql

Question

我试图删除表中的一个外键列，我已命名为ProductInvoice。我试图删除的列名为PersonID，来自表Person。当我运行查询

ALTER TABLE ProductInvoice 
DROP COLUMN PersonID; 

我得到这个错误...

Error Code: 1025. Error on rename of './jkripal/#sql-91c_19ff0' to './jkripal/ProductInvoice' (errno: 150) 

上的任何意见如何排查呢？我浏览过这个网站，找不到任何有帮助的答案。

我也尝试过这些查询

ALTER TABLE ProductInvoice DROP FOREIGN KEY `fkPerson`; 
ALTER TABLE ProductInvoice DROP COLUMN PersonID; 

并接收该响应...

Error Code: 1025. Error on rename of './jkripal/ProductInvoice' to './jkripal/#sql2-91c-1a05a' (errno: 152) 

这些是SHOW结果CREATE TABLE ProductInvoice

'ProductInvoice', 'CREATE TABLE `ProductInvoice` 
(\n `ProductInvoiceID` int(11) NOT NULL AUTO_INCREMENT, 
\n `PersonID` int(11) DEFAULT NULL, 
\n `ProductID` int(11) NOT NULL, 
\n `InvoiceID` int(11) NOT NULL, 
\n `TravelDate` varchar(255) DEFAULT NULL, 
\n `TicketNote` varchar(255) DEFAULT NULL, 
\n `Quantity` int(11) DEFAULT NULL, 
\n `InsuranceTicketCode` varchar(255) DEFAULT NULL, 
\n PRIMARY KEY (`ProductInvoiceID`), 
\n KEY `fkPerson` (`PersonID`), 
\n KEY `fk_ProductInvoice_to_Product` (`ProductID`), 
\n KEY `fk_ProductInvoice_to_Invoice` (`InvoiceID`), 
\n CONSTRAINT `ProductInvoice_ibfk_1` FOREIGN KEY (`PersonID`) REFERENCES `Person` (`PersonID`), 
\n CONSTRAINT `ProductInvoice_ibfk_2` FOREIGN KEY (`ProductID`) REFERENCES `Product` (`ProductID`), 
\n CONSTRAINT `ProductInvoice_ibfk_3` FOREIGN KEY (`InvoiceID`) REFERENCES `Invoice` (`InvoiceID`) 
\n) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8' 

我也曾尝试这无济于事

ALTER TABLE ProductInvoice DROP FOREIGN KEY `fkPerson`; 

DROP INDEX `fkPerson` ON ProductInvoice; 
ALTER TABLE ProductInvoice DROP COLUMN PersonID; 

Answer 1

您需要删除引用该列的外键约束。为此，您必须指定由CONSTRAINT的名称删除的外键。基于show create table中显示的输出，它看起来像约束被命名为ProductInvoice_ibfk_1。

因此，首先删除外键约束：

ALTER TABLE `ProductInvoice` DROP FOREIGN KEY `ProductInvoice_ibfk_1`; 

然后你就可以删除列。 （在删除列之前，可能还需要删除引用该列的索引。）