無法在函數外部使用變量

Question

我正在使用Koa模塊 - 節點js和mysql &遇到問題。 在註冊功能（內welcomeCtrl.js）

var bcrypt = require('bcrypt'); 
module.exports = { 
signup: function* (next) { 
bcrypt.genSalt(10, function(err, salt) { 
     console.log(salt); 
     bcrypt.hash(password, salt, function(err, hash) { 
      // Store hash in your password DB. 
      console.log(hash); //no error 
      var hashedPassword = hash; 
     }); 
     }); 
     console.log(bcrypt.hash.hash); //gives error 
      //or 
     console.log(bcrypt.hash.hahedPassword); //gives error 

     queryString = "insert into user(email,name, phone, password, course_id, dpt_id) values('%s','%s','%s','%s','%s','%s')"; 
     query = util.format(queryString, email, name, phone, hash, courseId, dptId); 
     results = yield databaseUtils.executeQuery(query); 
     this.redirect('/'); 
    } 
    } 

我打電話不同routes.js註冊後函數文件爲：

router.post('/signup', welcomeCtrl.signup); 

這裏是databaseUtils.js的executeQuerry函數文件

var executeQuery = function(query, callback) { 
pool.getConnection(function(err, connection) { 
    // Use the connection 
    connection.query(query, function(err, rows, fields) { 
     connection.release(); 
     if(err) { 
      err.mysqlQuery = query; 
      logger.logError(err); 
     } 

     if(typeof callback == "function") { 
      callback(err, rows); 
     } 
     // Don't use the connection here, it has been returned to the pool. 
    }); 
}); 
}; 
module.exports = { 
executeQuery: thunkify(executeQuery), 
executePlainQuery: executeQuery 
}; 

Is there any way to use hash variable outside the function so that it can be inserted in query?

Answer 1

您應該將您的查詢函數移動到的回調函數中。

bcrypt.genSalt(10, function(err, salt) { 
     console.log(salt); 

     bcrypt.hash(password, salt, function(err, hash) { 
     // Store hash in your password DB. 
     console.log(hash); //no error 
     queryString = "insert into user(email,name, phone, password, course_id, dpt_id) values('%s','%s','%s','%s','%s','%s')"; 
     query = util.format(queryString, email, name, phone, hash, courseId, dptId); 

     databaseUtils.executeQuery(query, function() { 
      this.redirect('/'); 
     }); 
     }); 
    }); 

問題是，你的redirect函數從哪裏來？除非您綁定這些函數，否則您將在this上放寬上下文。胖箭頭功能在你的設置中工作嗎？如果是這樣，你可以這樣做。