使用Sequelize连接Oracle时出现Cannot read properties of undefined错误

尝试用Sequelize连接Oracle数据库并获取数据时，出现错误：Cannot read properties of undefined (reading 'length'): undefined。相关代码如下：

连接代码 #

import { Sequelize, DataTypes } from "sequelize";
import _projects from "../models/projects.js";

export const getProjects = async (req, res, next) => {
var conn = new Sequelize({
            dialect: 'oracle',
            username: dbAdmin,
            password: dbPass,
            dialectOptions: { connectString: connStr } // 也试过{ connectionString: connStr }
        });

        function initModel(connection) {
            const projects = _projects.init(connection, DataTypes);
            return { projects };
        }

        var db = initModel(conn);
        const all_projects = await db.projects.findAll()
        console.log("all_projects", all_projects.rows); // 报错位置：Cannot read properties of undefined (reading 'length'): undefined
}

projects.js #

import _sequelize from 'sequelize';
const { Model, Sequelize } = _sequelize;

export default class projects extends Model {
    static init(sequelize, DataTypes) {
        return super.init({
            id: {
                type: DataTypes.UUID,
                allowNull: false,   
                primaryKey: true
            },
            credat: {
                type: DataTypes.DATE,
                allowNull: true,
                defaultValue: Sequelize.fn('getdate')
            },
            description: {
                type: DataTypes.STRING(1024),
                allowNull: true
            },
            picture: {
                type: DataTypes.STRING(255),
                allowNull: true
            },
            settings: {
                type: DataTypes.TEXT,
                allowNull: true
            },
            is_deleted: {
                type: DataTypes.INTEGER,
                allowNull: true
            }
        }, {
            sequelize,
            tableName: 'projects',
            schema: 'dbo',
            timestamps: false,
        });
    }
}

问题原因及修复方案 #

1. 核心错误点：findAll()返回的是直接的结果数组，而非带有rows属性的对象。你尝试访问all_projects.rows，但数组不存在该属性，进而触发读取length的未定义错误。
2. 基础修复：直接使用all_projects本身即可获取查询结果：

   console.log("all_projects", all_projects);
   

3. 额外优化建议：
   • 添加连接测试和错误捕获，避免隐性问题：

     export const getProjects = async (req, res, next) => {
       try {
         var conn = new Sequelize({
           dialect: 'oracle',
           username: dbAdmin,
           password: dbPass,
           dialectOptions: { connectString: connStr }
         });
         // 验证数据库连接
         await conn.authenticate();
         console.log('数据库连接成功');
     
         function initModel(connection) {
           const projects = _projects.init(connection, DataTypes);
           return { projects };
         }
     
         var db = initModel(conn);
         const all_projects = await db.projects.findAll();
         console.log("all_projects", all_projects);
         res.json(all_projects);
       } catch (error) {
         console.error('数据库操作失败:', error);
         next(error);
       }
     }
     

   • 检查依赖：确保安装了oracledb（Sequelize 6+连接Oracle需要此依赖）；
   • 验证schema：Oracle中默认schema通常是用户名而非dbo，确认schema: 'dbo'是否与实际数据库配置匹配；
   • 确认连接字符串格式：Oracle连接字符串一般为主机:端口/服务名，确保connStr格式正确。

内容的提问来源于stack exchange，提问作者crp