mongoskin unique index insert no error

mongoskin.insert.js

var db = require('mongoskin').db('localhost:27017/taohistorytest');
db.bind('histories');
db.histories.ensureIndex('num_iid', true, function() {console.log(arguments);});
db.histories.find().toArray(function(err, items){
    console.log(arguments);
});

db.histories.insert({num_iid: 1, title: 'test title'}, function() {
    console.log(arguments);
});

// 重复执行多次

{unique:true} 表示唯一索引，否则只是搜索优化的索引

db.histories.ensureIndex('num_iid', {unique: true}, function() {console.log(arguments);});

db.histories.ensureIndex(['num_iid',1], {unique: true}, function() {console.log(arguments);});

db.histories.ensureIndex({'num_iid':1}, {unique: true}, function() {console.log(arguments);});