如何向有外键约束的字表中插入记录？
我在mysql中建了两个表
mysql> describe room;
+--------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------+----------+------+-----+---------+-------+
| name | char(20) | NO | PRI | NULL | |
| doctor | char(20) | NO | | NULL | |
+--------+----------+------+-----+---------+-------+
2 rows in set (0.07 sec)
字表是
mysql> describe guahao;
+-------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| name | char(20) | NO | PRI | NULL | |
| sex | char(10) | NO | | NULL | |
| age | char(10) | NO | | NULL | |
| room | char(20) | NO | MUL | NULL | |
+-------+----------+------+-----+---------+-------+
4 rows in set (0.00 sec)
其中外键是room，on delete cascade on update cascade
我在命令行中向字表中插入数据没有问题,结果是
mysql> insert into guahao values
-> ('小张','男','30','皮肤科');
Query OK, 1 row affected (0.04 sec)
mysql> select * from guahao;
+--------+-----+-----+-----------+
| name | sex | age | room |
+--------+-----+-----+-----------+
| 王八 | 女 | 60 | 内科 |
| 钱二 | 男 | 40 | 脑科 |
| 赵一 | 男 | 20 | 五官科 |
| 孙三 | 女 | 35 | 骨科 |
| 寂寞 | 男 | 22 | 骨科 |
| 小张 | 男 | 30 | 皮肤科 |
| 小明 | 男 | 25 | 脑科 |
| 李四 | 男 | 30 | 皮肤科 |
+--------+-----+-----+-----------+
9 rows in set (0.00 sec)
但是我用PHP的时候，同样的插入语句，却会报错，错误信息如下：
Cannot add or update a child row: a foreign key constraint fails (`clinic`., CONSTRAINT `#sql-9e_13_ibfk_1` FOREIGN KEY (`room`) REFERENCES `room` (`name`) ON DELETE CASCADE ON UPDATE CASCADE)
请大神帮我看看问题在哪！跪求！哭了，问过一次，没解决问题。
回复讨论(解决方案)
为什么这个问题没有人回复？不是很难的问题啊
1、你的操作系统？
2、你的程序使用的字符集？
3、为了给帮助你的人提供便利，你应该给出
a、建表的 sql 指令
b、供测试用的 php 代码
吼吼,快来人解答~~
1、你的操作系统？
2、你的程序使用的字符集？
3、为了给帮助你的人提供便利，你应该给出
a、建表的 sql 指令
b、供测试用的 php 代码
1. 操作系统是MAC OS X
2. 字符集是
mysql> show variables like 'character%';
+--------------------------+--------------------------------------------------------+
| Variable_name | Value |
+--------------------------+--------------------------------------------------------+
| character_set_client | latin1 |
| character_set_connection | latin1 |
| character_set_database | latin1 |
| character_set_filesystem | binary |
| character_set_results | latin1 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/local/mysql-5.1.63-osx10.6-x86_64/share/charsets/ |
+--------------------------+--------------------------------------------------------+
8 rows in set (0.08 sec)
用于插入数据库的数据是从一个编码为UTF-8的HTML页面用post方法传到一个编码同样为UTF-8的PHP文件。
3.
建表的sql指令是在终端输入的 如下
mysql> create table room(name char(20) not null primary key, doctor char(20) not null) type=innodb;
Query OK, 0 rows affected, 1 warning (0.05 sec)
mysql> create table guahao -> (name char(20) not null primary key, -> sex char(10) not null,
-> age char(10) not null,
-> room char(20) not null,
-> foreign key(room) references room(name) on delete cascade on update cascade)
-> type=innodb;
Query OK, 0 rows affected, 1 warning (0.41 sec)
PHP代码是
1 |
|
字符集问题！
1、你的表中没有给字符类型字段设置字符集（默认 latin1）
2、你在连接数据库后没有声明字符集（缺少 set names 指令）
3、你说你使用了 utf-8 字符集，而程序中有 charset=GB18030
实际是使用了gbk 字符集
GB18030 是正式的国家标准，目前尚未在计算机中实现。所以实际使用的是其子集--GBK
忽略外键：SET FOREIGN_KEY_CHECKS = 0
字符集问题！
1、你的表中没有给字符类型字段设置字符集（默认 latin1）
2、你在连接数据库后没有声明字符集（缺少 set names 指令）
3、你说你使用了 utf-8 字符集，而程序中有 charset=GB18030
实际是使用了gbk 字符集
GB18030 是正式的国家标准，目前尚未在计算机中实现。所以实际使用的是其子集--GBK
那个问题我已经解决了，就是字符集问题，谢谢斑竹大神！这么多天才来结贴
字符集问题！
1、你的表中没有给字符类型字段设置字符集（默认 latin1）
2、你在连接数据库后没有声明字符集（缺少 set names 指令）
3、你说你使用了 utf-8 字符集，而程序中有 charset=GB18030
实际是使用了gbk 字符集
GB18030 是正式的国家标准，目前尚未在计算机中实现。所以实际使用的是其子集--GBK
……
版主你好，我用跟楼主一样的建表命令建表，但是不能插入和楼主一样的数据，提示foreign constraints fails，请问该怎么解决呢？
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
Alipay PHP SDK transfer error: How to solve the problem of 'Cannot declare class SignData'?
Apr 01, 2025 am 07:21 AM
Alipay PHP...
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
How does session hijacking work and how can you mitigate it in PHP?
Apr 06, 2025 am 12:02 AM
Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.
Describe the SOLID principles and how they apply to PHP development.
Apr 03, 2025 am 12:04 AM
The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.
How to debug CLI mode in PHPStorm?
Apr 01, 2025 pm 02:57 PM
How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...
How to automatically set permissions of unixsocket after system restart?
Mar 31, 2025 pm 11:54 PM
How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
How to send a POST request containing JSON data using PHP's cURL library?
Apr 01, 2025 pm 03:12 PM
Sending JSON data using PHP's cURL library In PHP development, it is often necessary to interact with external APIs. One of the common ways is to use cURL library to send POST�...
