终端语法错误：之后参数列表丢失）

Question

试图通过这段代码连接到蒙戈DB数据库：

const mongoose = require('mongoose'); 

//Connect to mongodb 
mongoose.connect('mongodb://localhost/testaroo'); 

mongoose.connection.once('open'.function(){ 
console.log('Connection has been made');           

}).on('error', function(error){ 
console.log('Connection Error:', error); 
}); 

但是，当我试图通过

终端连接到它

MG-MC-iMacs-iMac:~ MG-MC-TJUBA$ node mongodb/PingPongDB/connection.js 

它给我这个错误：

/Users/MG-MC-TJUBA/mongodb/PingPongDB/connection.js:6 
mongoose.connection.once('open'.function(){ 
            ^

SyntaxError: missing) after argument list 
at createScript (vm.js:74:10) 
at Object.runInThisContext (vm.js:116:10) 
at Module._compile (module.js:533:28) 
at Object.Module._extensions..js (module.js:580:10) 
at Module.load (module.js:503:32) 
at tryModuleLoad (module.js:466:12) 
at Function.Module._load (module.js:458:3) 
at Function.Module.runMain (module.js:605:10) 
at startup (bootstrap_node.js:158:16) 
at bootstrap_node.js:575:3 

从我看到它说我错过了一个'）'已经存在和需要。

Answer 1

语法错误在打开后你的代码

mongoose.connection.once('open', function(){ 
console.log('Connection has been made');           

}).on('error', function(error){ 
console.log('Connection Error:', error); 
});