这个问题在这里已有答案：
我有一个外键问题，虽然我已经在父表中添加了必要的信息 . 这是模式，select语句，用于显示外键存在于父表中，以及在子表中插入新数据的错误：
MariaDB [scansmusic]> show create table chhymnal;
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| chhymnal | CREATE TABLE `chhymnal` (<br>
`CHhymnalID` int(5) unsigned NOT NULL,<br>
`Title` varchar(30) DEFAULT NULL,<br>
`CHNumber` int(5) unsigned DEFAULT NULL,<br>
`Type` varchar(1) DEFAULT NULL,<br>
`WorshipItemType` varchar(30) DEFAULT NULL,<br>
`DateLastSung` date DEFAULT NULL,<br>
`HighNote` varchar(5) DEFAULT NULL,<br>
`UseThisWeek` tinyint(1) DEFAULT NULL,<br>
`ServiceOrder` int(2) unsigned DEFAULT NULL,<br>
`StartKey` varchar(2) DEFAULT NULL,<br>
`EndKey` varchar(2) DEFAULT NULL,<br>
`Tempo` int(1) unsigned DEFAULT NULL,<br>
`TimeSig` varchar(7) DEFAULT NULL,<br>
`CCLINumb` varchar(10) DEFAULT NULL,<br>
PRIMARY KEY (`CHhymnalID`)<br>
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |<br>
+----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1排（0.00秒）
MariaDB [兹音乐]> MariaDB [scanningmusic]>显示创建表格chimage;
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| <br>chimages | CREATE TABLE `chimages` (<br>
`CHImageID` int(5) unsigned NOT NULL,<br>
`ImagePath` varchar(50) DEFAULT NULL,<br>
`Instrument` varchar(30) DEFAULT NULL,<br>
`CHhymnalID` int(5) DEFAULT NULL,<br>
PRIMARY KEY (`CHImageID`),<br>
CONSTRAINT `fk_images` FOREIGN KEY (`CHImageID`) REFERENCES `chhymnal` (`CHhymnalID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+<br>
1 row in set (0.00 sec)
MariaDB [scannedmusic]> SELECT * FROM `chhymnal` WHERE `CHhymnalID` = 343;
+------------+-------------------------+----------+------+-----------------+--------------+----------+-------------+--------------+----------+--------+-------+---------+----------+
| CHhymnalID | Title | CHNumber | Type | WorshipItemType | DateLastSung | HighNote | UseThisWeek | ServiceOrder | StartKey | EndKey | Tempo | TimeSig | CCLINumb |<br>
+------------+-------------------------+----------+------+-----------------+--------------+----------+-------------+--------------+----------+--------+-------+---------+----------+
| 343 | What a Day That Will Be | 762 | h | Hymn | 0000-00-00 | Db | 0 | 12 | Ab | Ab | 3 | 3/4 | |
+------------+-------------------------+----------+------+-----------------+--------------+----------+-------------+--------------+----------+--------+-------+---------+----------+
1排（0.00秒）
MariaDB [scannedmusic]> INSERT INTO <br>Chimages(`CHImageID`,`ImagePath`,`CHhymnalID`) VALUES ( 393, "\\BMP\\762_o1.bmp",343);
ERROR 1452（23000）：无法添加或更新子行：外键约束失败（scansmusic.chimages，CONSTRAINT fk_images FOREIGN KEY（CHImageID）REFERENCES chhymnal（CHhymnalID））
1 回答
你正在看错列 . 在表
chhymnal中，没有chhymnalid = 393的行 .您的
SELECT语句建议您检查chhymnal表中的chhymnalid，但您的外键约束适用于chimageid，INSERT语句中包含393值 .有两个选项 - 其中一个必须是真的：
您的意思是在创建外键约束时键入的内容，并且表
chhymnal中没有chhymnalid = 393的行您在外键约束中错误地引用了列名称，它应该是
chhymnalid而不是chimageid