Onela一个Node.js开源的ORM对象关系映射框架

Onela是基于node.js开源的基于对象的映射框架，支持各种关系数据库数据基础设施。 同时支持各种数据库对象的读写分离，数据库实例垂直拆分。 在onela架构之上，您可以体验无SQL编程的乐趣，您只需要关注业务逻辑代码部分。 而且，我将在后面的版本的支持下加入分布式缓存来实现前端和后端的node.js程序来挑战大规模应用的情况。

重大更新：v2.0版本发布

此版本重大更新，原有如果使用了V2.0.0之前的版本请注意，升级到最新版，最原有代码也需要微调。

特别感谢Hugh-won在v2.0.0版本改进提供帮助~

目前（v2.3.0）已经支持 MySQL、PostgreSQL、SQL Server、SQLite数据库

步骤一：安装node模块（step 1 npm install node_modules）

npm install onela		// 项目核心包

依赖包安装
npm install mysql	// MySQL数据库
npm install pg		// PostgreSQL数据库
npm install sqlite3	// SQLite数据库
npm install tedious	// SQL Server数据库

步骤二：配置数据源（step 2 Mapping data sources）

数据库的配置可以配置在config全局配置中，在初始化调用取出来就可以了了

/**
 * 数据库配置，可以初始化多个数据库实例
 */
let dbconfig = [{
    "engine": "default",    // 数据库实例名称
    "type": "mysql",        // 数据库类型：MYSQL（不区分大小写）,支持类型：mysql、postgresql、sqlite、sqlserver
    "value": {
        "connectionLimit": 5,
        "host": "localhost",
        "user": "",
        "password": "",
        "database": "todo"
    }
},
{
    "engine": "default",
    "type": "PostgreSQL",           // 数据库类型：PostgreSQL（不区分大小写）
    "value": {
        "port": 3432,
        "host": "127.0.0.1",
        "user": "manor",
        "password": "test",
        "database": "test_db"
    }
}];

步骤三：Onela ORM对象初始化（step 3 Onela ORM object initialization）

const {Onela, OnelaBaseModel}  = require("onela");
// 初始化Onela模块（建议全局初始化）
Onela.init(dbconfig);

步骤四：单例（数据表）对象配置以及方法的扩展封装

// 在OnelaBaseModel类中封装了常用的ORM方法
class ToDoManager extends OnelaBaseModel {
    // 可以在此自定义扩展方法（默认封装没有的方法）
}

/**
 * 【重要】单例模式，数据表配置
 * tableName：数据表名
 * engine：数据库引擎名称，需要和dbconfig配置的名称对应起来
 * fields[n].name:数据表字段名
 * fields[n].type:数据表字段类型
 * fields[n].default:默认值
 * */
ToDoManager.configs = {
    fields: [
        {name: "id", type: "int", default: null},
        {name: "content", type: "varchar"},
        {name: "is_done", type: "int", default: 0},
        {
            name: "create_time", type: "datetime", default: () => {
            return new Date()
        }
        },
        {name: "finish_time", type: "datetime", default: null}
    ],
    tableName: "todos",
    engine: "default"
};

步骤五：常用CRUD操作代码示例（step 5 Examples of common CRUD operation code）

到这一步骤，可以直接使用ORM的方法了，增删改查，包含事务处理。

// 【重要】单例模式，数据表配置
ToDoManager.configs = {
    fields: [
        {name: "id", type: "int", default: null},
        {name: "content", type: "varchar"},
        {name: "is_done", type: "int", default: 0},
        {
            name: "create_time", type: "datetime", default: () => {
            return new Date()
        }
        },
        {name: "finish_time", type: "datetime", default: null}
    ],
    tableName: "todos",
    engine: "default"
};

/**
 * 事务
 */
ToDoManager.transaction().then(t => {
    // 先新增一条记录
    ToDoManager.insertEntity({
        "content": "测试事务"
    }, {transaction: t})
        .then(data => {
            // 再对新增的记录执行修改
            return ToDoManager.updateEntity({
                "update": [
                    {"key": "content", "value": "事务修改", "operator": "replace"}    // 修改了content字段
                ],
                "where": [
                    {"logic": "and", "key": "id", operator: "=", "value": 8}
                ]
            }, {transaction: t});
        })
        .then(data => {
            console.log('执行结果', data);
            t.commit().then(d=>{
                console.log(d);
            });
        })
        .catch(ex => {
            console.log('事务异常回滚', ex);
            t.rollback().then(d=>{
                console.log(d);
            });
        });
});


/**
 * 单例模式：数据查询
 */
ToDoManager.getEntity({
    where: [
        //{"logic": "and", "key": "id", "operator": "=", "value": 1}
    ]
}, null).then(data => {
    console.log('查询结果', data)
}).then();

/**
 * 单例模式：新增
 */
ToDoManager.insertEntity({
    "content":"测试"
}).then(data=>{console.log('查询结果',data)});

/**
 * 单例模式：分页查询
 */
ToDoManager.getEntityList({
    "where": [
            //{"logic": "and", "key": "id", "operator": "=", "value": 1}
        ]
}).then(console.log);

/**
 * 单例模式：新增
 */
ToDoManager.insertEntity({
    content: "设计智能保险顾问的用户体系"
}).then(console.log);

/**
 * 单例模式：批量新增
 */
ToDoManager.insertBatch([
    {content: "测试1"},
    {content: "测试2"},
    {content: "测试3"}
]).then(console.log);

/**
 * 单例模式：删除（物理删除，不推荐使用）
 */
ToDoManager.deleteEntity({
    "where": [
        {"key": "id", operator: "in", value: [12360,12361], logic: "and"},
        // {"key": "is_done", operator: "=", value: 1, logic: "and"}
    ]
}).then(console.log);

/**
 * 单例模式：更新（对于删除，建议使用逻辑删除）
 */
ToDoManager.updateEntity({
    update: [
        {key: "is_done", value: 1, operator: "replace"}
    ],
    where: [
        {"key": "id", operator: "in", value: [12362], logic: "and"},
    ]
}).then(console.log);

/**
 * 单例模式：实时统计
 */
ToDoManager.getEntityByAggregate({
    // where:
    "aggregate":[
        {"function": "count", "field": "is_done", "name": "undone_tasks"},
    ]
}).then(console.log);

Ok, you can now play happily~

Use instance to show（方法使用示例）

Query example（示例：查询）

There are several ways to apply the query to different business scenarios. Paging query, waterfall flow inquiries, Standard query

	//parameter
    let p = {
        "select": ["t.id"],     //Specify the output field, query all fields, use t. * Or select attributes by default
        "where": [
            {"logic": "and", "key": 'valid', "operator": "=", "value": 1},
            {"logic": "and", "key": 'id', "operator": "=", "value": id}
        ],
        "orderBy": {"created_time": "DESC"},
        "limit": [0, 1]         //Take the first data of the query results
    }
    //execute select
    ToDoManager.getEntity(p)
        .then(function (data) {
            resolve(data);
        })
        .catch(function (err) {
            reject(err);
        });

Insert example（示例：新增）

There is also a new batch method db_instance.insertBatch(arr),The incoming value is an array of objects

	//parameter
    let p = {
        "name":"Sandy",
        "sex":"female",
        "email":"[email protected]"
        //……
        //Other fields are added in turn
    }
    //execute insert
    ToDoManager.insertEntity(p)
        .then((data)=> {
            resolve(data);
        })
        .catch(function (err) {
            reject(err);
        });

Update example（示例：更新）

There are two main ways to update the field,replace or plus

 //parameter
 var p = {
     "update": [
         //operator：replace update
         {"key": "name", "value": 'Sandy', "operator": "replace"},
         //operator：plus update,The field type needs to be a numeric type
         {"key": "money", "value": 2, "operator": "plus"},
         //operator：reduce update,The field type needs to be a numeric type
         {"key": "score", "value": 1, "operator": "reduce"}
         
     ],
     "where": [
        //where条件：一般以主键id作为更新条件，支持多条件组合语
        {"logic": "and","key": "id",  "operator": "=", "value": 'abc'}
     ]
 }
 //execute update
  ToDoManager.updateEntity(p)
        .then((data)=> {
            resolve(data);
        })
        .catch(function (err) {
            reject(err);
        });

Update example（示例：复杂SQL更新）

case when then else end 用法举例

 SQL示例：update todos set is_done=1,content= (CASE id WHEN 12381 THEN '修改结果A' WHEN 12384 THEN '修改结果B' END)  where  1=1  and id in (12381, 12384); 
 
 //parameter
 var p = {
    update: [
        {key: "is_done", value: 1, operator: "replace"},
        {
            "key": "content",		 //update field
            "case_field": "id",		 //balance =  CASE id
            "case_item": [
                {"case_value": 3, "value": "修改结果A", "operator": "replace"},		//WHEN '001' THEN 1
                {"case_value": 6, "value": "修改结果B", "operator": "replace"}		//WHEN '001' THEN balance+2
            ]
        }
    ],
    where: [
        {"key": "id", operator: "in", value: [3,6], logic: "and"},
    ]
 }
 //execute update
  ToDoManager.updateEntity(p)
        .then((data)=> {
            resolve(data);
        })
        .catch(function (err) {
            reject(err);
        });

Delete example（示例：删除）

Physical deletion, generally do not recommend this operation, it is recommended to delete the logic

	//parameter
    let p = {
        "where": [
            //Allow multiple query conditions
            //{"key": "字段名1", "value": "值", "logic": "连接联符 （默认为and 非必须 ）", operator: "关联符号 (默认为: =)"},
            {"key": "id", "value": "abc", "logic": "and", operator: "="}
        ]
    }
    //execute delete
    ToDoManager.deleteEntity(p)
        .then((data=>) {
            resolve(data);
        })
        .catch(function (err) {
            reject(err);
        });

sql example（实例：直接执行SQL案例）

Not recommended，Direct execution of sql can only be applied to specific types of databases

var sql = "SELECT * FROM tableName Where ...";
 
 ToDoManager.streak(sql).then(result =>{
 	// Get execution results
 }); 

Transaction example（实例：事务）

Can only achieve local Transaction

// transaction
ToDoManager.transaction().then(t => {
    // 先新增一条记录
    ToDoManager.insertEntity({
        "content": "测试"
    }, {transaction: t})
        .then(data => {
            // 再对新增的记录执行修改
            return ToDoManager.updateEntity({
                "update": [
                    {"key": "content", "value": "执行修改测试", "operator": "replace"}    // 修改了content字段
                ],
                "where": [
                    {"logic": "and", "key": "id", operator: "=", "value": data.insertId}
                ]
            }, {transaction: t});
        })
        .then(data => {
            console.log('执行结果', data);
            // 事务提交
            t.commit();
        })
        .catch(ex => {
            console.log('事务异常回滚', ex.message);
            // 事务回滚
            t.rollback();
        });
});

onela.js v1 版本已经下线

在就版本中模块引用需要批量调整下(2.0.0之前的老版本兼容）
const onela = require('onela');
更改为：
const onela = require('onela').Old;

此版本文档已经更新为最新文档，v2.0.0之前的老版本文档请查看：老版本文档