我尝试使用Sequelize + nodeJs使用现有的MySQL数据库创建多对多的关系:
以下是我的表格: - " usr"表:usr_id(PK) - 中级" usr_role" :usr_id,role_id - "角色" table:role_id
这是我的模特 "用户"机型:
"use strict";
var bcrypt = require('bcryptjs');
module.exports = function(sequelize, DataTypes) {
var User = sequelize.define('User', {
usrid : {
type: DataTypes.INTEGER,
primaryKey: true,
autoIncrement: true,
allowNull: false,
field:'usr_id'
},
name :{
type: DataTypes.STRING,
allowNull: false,
field:'usr_name'
},
}, {
timestamps: false,
freezeTableName: true,
tableName: 'usr',
name:'User',
underscored:'true',
classMethods: {
associate:function(models){
User.belongsToMany(models.Role, { through: 'UserRole', foreignKey:'usr_id', as:'UserRoles'});
}
}
}
);
return User;
};

"作用"模型
module.exports = function(sequelize, DataTypes) {
var Role = sequelize.define('Role', {
id : {
type: DataTypes.INTEGER,
primaryKey: true,
autoIncrement: true,
allowNull: false,
field:'role_id'
},
name :{
type: DataTypes.STRING,
allowNull: false,
field:'role_name'
},
},{
timestamps: false,
freezeTableName: true,
tableName: 'role_ref',
underscored:'true',
classMethods: {
associate:function(models){
Role.belongsToMany(models.User, {
through: 'UserRole',
foreignKey:'role_id'});
}
}
}
)
return Role;
};

E:\nodejsWS\learn\node_modules\inflection\lib\inflection.js:795
var str_path = str.split( '::' );
^
TypeError: Cannot read property 'split' of undefined
at Object.inflector.underscore
(E:\nodejsWS\learn\node_modules\inflection\lib\inflection.js:795:25)
at Object.module.exports.underscoredIf
(E:\nodejsWS\learn\node_modules\sequelize\lib\utils.js:28:27)
at new BelongsToMany (E:\nodejsWS\learn\node_modules\sequelize
\lib\associations\belongs-to-many.js:134:15)
at Mixin.belongsToMany
(E:\nodejsWS\learn\node_modules\sequelize\lib\associations
\mixin.js:264:21)
at sequelize.define.classMethods.associate
(E:\nodejsWS\learn\models\Role.js:29:12)
at E:\nodejsWS\learn\models\index.js:50:21
这是我的index.js
// Import models
fs
.readdirSync(__dirname)
.filter(function(file) {
return (file.indexOf(".") !== 0) && (file !== "index.js");
})
.forEach(function(file) {
var model = sequelize.import(path.join(__dirname, file));
db[model.name] = model;
});
//associate models
Object.keys(db).forEach(function(modelName) {
if ("associate" in db[modelName]) {
console.log(db);
db[modelName].associate(db);
}
});

第50行引用导致错误的db [modelName] .associate(db)。
有人可以指导我做错了什么。我是否需要手动创建中间模型' UserRole'。非常感激您的帮忙。感谢。
答案 0 :(得分:0)
您需要在belongsToMany
配置中指定实际的中间表名称,或者定义模型UserRole
。此外,除非您的中间表包含字段,否则您可能还需要指定timestamps: false
。所以,例如:
Role.belongsToMany(models.User, {
through: 'usr_role',
foreignKey:'role_id',
timestamps: false
});
这将导致sequelize在其构建的查询中使用该表而无需定义模型,并且将阻止它从User表或中间层请求时间戳字段。