postgresql 未处理的拒绝 SequelizeDatabaseError：关系“用户”不存在
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Unhandled rejection SequelizeDatabaseError: relation "users" does not exist
提问by Ahmed Ghrib
I am getting started with Sequelize. I am following the documentation they are providing on their website :http://docs.sequelizejs.com/manual/installation/getting-started.html
我正在开始使用 Sequelize。我正在关注他们在其网站上提供的文档：http: //docs.sequelizejs.com/manual/installation/getting-started.html
const Sequelize = require('sequelize');
const sequelize = new Sequelize('haha', 'postgres', 'postgres', {
host: 'localhost',
dialect: 'postgres',
operatorsAliases: false,
pool: {
max: 5,
min: 0,
acquire: 30000,
idle: 10000
},
// SQLite only
storage: 'path/to/database.sqlite'
});
sequelize
.authenticate()
.then(() => {
console.log('Connection has been established successfully.');
})
.catch(err => {
console.error('Unable to connect to the database:', err);
});
const User = sequelize.define('user', {
firstName: {
type: Sequelize.STRING
},
lastName: {
type: Sequelize.STRING
}
});
// force: true will drop the table if it already exists
User.sync({force: true}).then(() => {
// Table created
return User.create({
firstName: 'John',
lastName: 'Hancock'
});
});
Up until here, everything works perfectly. And the table "user" is correctly built and populated. (Although I do not understand Sequelize appends an "s" automatically to "user", any explanation.)
到这里为止，一切正常。并且“用户”表已正确构建和填充。（虽然我不明白 Sequelize 会自动将“s”附加到“user”，任何解释。）
However when I add the following portion of code:
但是，当我添加以下代码部分时：
User.findAll().then(users => {
console.log(users)
})
I get this error :
我收到此错误：
Unhandled rejection SequelizeDatabaseError: relation "users" does not exist
未处理的拒绝 SequelizeDatabaseError：关系“用户”不存在
So my questions are:
所以我的问题是：
- Why does Sequelize add an "s" to user. (I know it makes sense but shouldn't the developer decide that)
- What is causing that error? I followed the documentation but it still didn't work?
- 为什么 Sequelize 向用户添加“s”。（我知道这是有道理的，但开发人员不应该决定）
- 是什么导致了这个错误？我遵循了文档，但它仍然不起作用？
回答by ccordon
When you are defining your model you can add configurations, in this case the option that you must add is freezeTableNameprevents the names from being plural.
当您定义模型时，您可以添加配置，在这种情况下，您必须添加的选项是freezeTableName防止名称为复数。
const User = sequelize.define('user', {
firstName: {
type: Sequelize.STRING
},
lastName: {
type: Sequelize.STRING
}
}, {
// disable the modification of table names; By default, sequelize will automatically
// transform all passed model names (first parameter of define) into plural.
// if you don't want that, set the following
freezeTableName: true,
});
回答by JamesSchiiller
Run that code twice.
运行该代码两次。
Before running the second time, comment out the following code,
在第二次运行之前，注释掉以下代码，
// force: true will drop the table if it already exists
User.sync({force: true}).then(() => {
// Table created
return User.create({
firstName: 'John',
lastName: 'Hancock'
});
});
回答by Sahan Dissanayaka
There is another interesting way you can avoid this. But you need to really focus on this way of implementation.
还有另一种有趣的方法可以避免这种情况。但是您需要真正关注这种实现方式。
const User = sequelize.define("user", {
firstname: {
type: Sequelize.STRING
},
lastname: {
type: Sequelize.STRING
}
});
you intentionally put userhere and use usersin other places of coding(Assume sequelize will automatically transform all passed model names (first parameter of define) into plural) . This way of coding will simplify your code.
你故意放在user这里并users在其他地方使用（假设 sequelize 会自动将所有传递的模型名称（定义的第一个参数）转换为复数）。这种编码方式将简化您的代码。
