MySQL 无法使 FOREIGN KEY 命令工作

Question

我发现的一切都说明了我试图拉出的两个项目在某些方面与它们的父项目不同，但它们并没有

CREATE TABLE Servers (
serverId VARCHAR(255) NOT NULL PRIMARY KEY,
serverName VARCHAR(255) NOT NULL,
serverOwnerId VARCHAR(255) NOT NULL,
serverOwnerName VARCHAR(255) NOT NULL,
paidRole BOOLEAN NOT NULL
);

CREATE TABLE ServerConfigurable (
serverId VARCHAR(255) NOT NULL PRIMARY KEY,
serverName VARCHAR(255) NOT NULL,
cmdPrefix VARCHAR(16) DEFAULT '!',
globalUngate BOOLEAN NOT NULL,
globalAutoungate BOOLEAN NOT NULL,
autoungateWebhook VARCHAR(255) NOT NULL,
ungateWebhook VARCHAR(255) NOT NULL,
embedHexcolor VARCHAR(32) NOT NULL,
webhookName VARCHAR(255) DEFAULT 'Gate Bot',
webhookImage VARCHAR(255) DEFAULT 'https://imgur.com/a/eIULgfA',
footerMessage VARCHAR(255) DEFAULT 'Gate Bot V1.0.1',
footerImage VARCHAR(255) DEFAULT 'https://imgur.com/a/eIULgfA',
FOREIGN KEY Servers REFERENCES Servers(serverId),
FOREIGN KEY Servers REFERENCES Servers(serverName)
);

我得到的错误是

ERROR 1064 (42000)：您的 SQL 语法有误；查看与您的 MySQL 服务器版本对应的手册，了解在“REFERENCES Servers(serverId)”附近使用的正确语法， FOREIGN KEY serverName REFERENCES 服务器（第 14 行的 serverNa'

Answer 1

每个引用列都必须有一个索引

所以你可以做到

CREATE TABLE Servers (
serverId VARCHAR(255) NOT NULL PRIMARY KEY,
serverName VARCHAR(255) NOT NULL,
serverOwnerId VARCHAR(255) NOT NULL,
serverOwnerName VARCHAR(255) NOT NULL,
paidRole BOOLEAN NOT NULL,
KEY(serverName)
);

CREATE TABLE ServerConfigurable (
serverId VARCHAR(255) NOT NULL PRIMARY KEY,
serverName VARCHAR(255) NOT NULL,
cmdPrefix VARCHAR(16) DEFAULT '!',
globalUngate BOOLEAN NOT NULL,
globalAutoungate BOOLEAN NOT NULL,
autoungateWebhook VARCHAR(255) NOT NULL,
ungateWebhook VARCHAR(255) NOT NULL,
embedHexcolor VARCHAR(32) NOT NULL,
webhookName VARCHAR(255) DEFAULT 'Gate Bot',
webhookImage VARCHAR(255) DEFAULT 'https://imgur.com/a/eIULgfA',
footerMessage VARCHAR(255) DEFAULT 'Gate Bot V1.0.1',
footerImage VARCHAR(255) DEFAULT 'https://imgur.com/a/eIULgfA',
FOREIGN KEY (serverId) REFERENCES Servers(serverId),
FOREIGN KEY (serverName) REFERENCES Servers(serverName)
);

或者做这样的事情

CREATE TABLE Servers (
serverId VARCHAR(255) NOT NULL PRIMARY KEY,
serverName VARCHAR(255) NOT NULL,
serverOwnerId VARCHAR(255) NOT NULL,
serverOwnerName VARCHAR(255) NOT NULL,
paidRole BOOLEAN NOT NULL,
KEY(serverId,serverName)
);

CREATE TABLE ServerConfigurable (
serverId VARCHAR(255) NOT NULL PRIMARY KEY,
serverName VARCHAR(255) NOT NULL,
cmdPrefix VARCHAR(16) DEFAULT '!',
globalUngate BOOLEAN NOT NULL,
globalAutoungate BOOLEAN NOT NULL,
autoungateWebhook VARCHAR(255) NOT NULL,
ungateWebhook VARCHAR(255) NOT NULL,
embedHexcolor VARCHAR(32) NOT NULL,
webhookName VARCHAR(255) DEFAULT 'Gate Bot',
webhookImage VARCHAR(255) DEFAULT 'https://imgur.com/a/eIULgfA',
footerMessage VARCHAR(255) DEFAULT 'Gate Bot V1.0.1',
footerImage VARCHAR(255) DEFAULT 'https://imgur.com/a/eIULgfA',
FOREIGN KEY (serverId,serverName) REFERENCES Servers(serverId,serverName)
);

MySQL 无法使 FOREIGN KEY 命令工作

MySQL trouble getting FOREIGN KEY command to work

mysql

foreign-keys