的mysql的NodeJS不能执行查询

Question

我使用这个包：https://github.com/mysqljs/mysql

this_obj.pool.getConnection似乎无法在所有的执行，因为我内建成的console.log。

MyLib.prototype.device_table_get_username = function(this_obj, user_id) { 
    return new Promise(function (resolve, reject) { 
    var sql = "select username from laravel_device where id = " + "'" + user_id + "'"; 

    console.log(); 
    console.log("---------"); 
    console.log(sql); 

    // NOTE: ----------- it seems not running at all here. ----------------- 
    this_obj.pool.getConnection(function(err, connection) { 
     console.log("1. no output here"); 

     connection.query(sql, function(err, rows, fields) { 
     console.log("2. no output here"); 

     connection.release(); 

     if (err) throw err; 

     var msg_obj = { 
      rows: rows 
     }; 

     resolve(msg_obj); 
     }); 
    }); 
    }); 
} 

的完整代码

var config = require("../config.js"); 
var Promise = require('bluebird'); 
var mysql = require("mysql"); 
var ON_DEATH = require('death'); 


// Constructor 
function MyLib() { 
    // var 
    this.db_username = config.db_username; 
    this.db_password = config.db_password; 
    this.db_name = config.db_name; 
    this.db_host = config.db_host; 

    this.pool = null; 
} 


MyLib.prototype.connect_mysql = function() { 
    this.pool = mysql.createPool({ 
     connectionLimit: 400, 
     host: this.db_host, 
    user: this.db_username, 
    password: this.db_password, 
    database: this.db_name 
    }); 
} 


// close mysql 
MyLib.prototype.close_mysql = function() { 
    this.pool.end(function (err) { 
    // all connections in the pool have ended 
    }); 
} 


MyLib.prototype.clean_up = function() { 
    var this_obj = this; 
    ON_DEATH(function(signal, err) { 
     console.log(); 
    console.log("---- script interupted ----"); 

    console.log("close mysql"); 
    this_obj.close_mysql(); 
    }); 
} 


MyLib.prototype.run = function() { 
    var this_obj = this; 
    this.mqtt_acl_get_rows().then(function(msg_obj){ 
    var rows = msg_obj.rows; 

    // http://stackoverflow.com/questions/28736452/bluebird-promise-serial-iteration-and-resolve-to-modified-array 
    this_obj.map_series(this_obj, rows, this_obj.process_mqtt_acl_row).then(function(){ 

     // finish 
     process.exit(); 
    }); 


    }); 

} 


MyLib.prototype.device_table_get_username = function(this_obj, user_id) { 
    return new Promise(function (resolve, reject) { 
    var sql = "select username from laravel_device where id = " + "'" + user_id + "'"; 

    console.log(); 
    console.log("---------"); 
    console.log(sql); 

    // NOTE: ----------- it seems not running at all here. ----------------- 
    this_obj.pool.getConnection(function(err, connection) { 
     console.log("1. no output here"); 

     connection.query(sql, function(err, rows, fields) { 
     console.log("2. no output here"); 

     connection.release(); 

     if (err) throw err; 

     var msg_obj = { 
      rows: rows 
     }; 

     resolve(msg_obj); 
     }); 
    }); 
    }); 
} 



MyLib.prototype.user_table_get_username = function(user_id) { 
    var this_obj = this; 

    return new Promise(function (resolve, reject) { 
    var sql = "select username from laravel_users where id = " + "'" + user_id + "'"; 

    console.log(); 
    console.log("---------"); 
    console.log(sql); 

    // NOTE: ----------- it seems not running at all here. ----------------- 
    this_obj.pool.getConnection(function(err, connection) { 
     connection.query(sql, function(err, rows, fields) { 
     connection.release(); 

     if (err) throw err; 

     var msg_obj = { 
      rows: rows 
     }; 
     resolve(msg_obj); 
     }); 
    }); 
    }); 
} 


MyLib.prototype.process_mqtt_acl_row = function(this_obj, value, index, length) { 
    var row_id = value.id; 
    var user_id = value.user_id; 
    var mqtt_user_type_id = value.mqtt_user_type_id; 
    var is_device = 2; 
    var is_human = 1; 

    if(mqtt_user_type_id == is_device) { 
    console.log("-device-"); 
     this_obj.device_table_get_username(this_obj, user_id).then(function(msg_obj){  
      var rows = msg_obj.rows; 
     console.log(msg_obj); 
     }); 
    } 
    else if(mqtt_user_type_id == is_human) { 
    console.log("-human-"); 
     this_obj.user_table_get_username(user_id).then(function(msg_obj){ 
      var rows = msg_obj.rows; 
     console.log(msg_obj); 
     }); 
    } 
    else { 
    console.log("process_mqtt_acl_row, not calling"); 
    } 

    return value; 
} 


// http://stackoverflow.com/questions/28736452/bluebird-promise-serial-iteration-and-resolve-to-modified-array 
MyLib.prototype.map_series = function(this_obj, things, fn) { 
    var results = []; 

    return Promise.each(things, function(value, index, length) { 
    // value 
    // value == { id: 303, user_id: 4, mqtt_user_type_id: 1 } 

    // call fn 
    var ret = fn(this_obj, value, index, length); 

    // push result 
    results.push(ret); 
    return ret; 
    }); 
} 


MyLib.prototype.mqtt_acl_get_rows = function() { 
    var this_obj = this; 

    return new Promise(function (resolve, reject) { 
     var sql = "select id, user_id, mqtt_user_type_id from laravel_mqtt_acl order by id asc"; 

    console.log(); 
    console.log("---------"); 
    console.log(sql); 

    // NOTE: this one is working 
     this_obj.pool.getConnection(function(err, connection) { 
     connection.query(sql, function(err, rows, fields) { 
     connection.release(); 

     if (err) throw err; 

     var msg_obj = { 
      rows: rows 
     }; 
     resolve(msg_obj); 
     }); 
    }); 
    }); 

} 



module.exports = MyLib; 

更新1 我改变了它从connectionLimit: 400到connectionLimit: 4。它似乎能够连接。我会做更多的测试。

Answer 1

尝试工作此代码与MySQL数据库 第一写入代码用于配置数据基础/分贝像

var config = require('./config'); 

变种的MySQL =要求（ '的MySQL'）; //对于mysql连接

//CONFIGURATION FOR CREATING POOL 
var pool = mysql.createPool({ 
    connectionLimit:config.connectionLimit, 
    host: config.host, 
    user: config.user, 
    password: config.password, 
    database: config.database 
}); 

module.exports = pool; 

//在您想要使用它的其他文件中。

var pool = require('../config/db'); 

pool.getConnection(function (err, connection) { 
    if (!err) 
    { 
     email = req.user.email 
     connection.query('delete from notification where user_id=(select id from users where email=?)', [email], 
      function (err, noti_data){ 
       if (!err) 
       { 
        deleted_device = noti_data.affectedRows 
        console.log('User Logout Successfully...'); 
        res.json({'code': 200, 'status': 'Success', 'message': 'User Logout Successfully...'}); 
        logger.info('URL=', URL.url, 'Responce=', 'User Logout Successfully...', 'Email id=', email); 
        return; 
       } 
       else 
       { 
        console.log('Error for deleting and selecing details..', err); 
        res.json({'code': 200,'status': 'Error','message': 'Error for deleting and selecing details..'}); 
        logger.error('URL=',URL.url, 'Responce=','Error for deleting and selecing details..','Email id=', email); 
        return; 
       } 
      }); 
      connection.release(); 
    } 
    else 
    { 
     Errors.Connection_Error(res); 
    } 
});