命令 - 修改数据类型

修改 - 数据类型

新方法

//要改4+2个地方
//string转为int类型
  db.your_collection.find({"your_role":{$type:2}}).forEach(function(x){
    db.your_collection.update({ your_role : { $type: 2 } }, {$set: {"your_role": NumberInt(x.your_role)}});
})

//string转为double类型
db.your_collection.find({'your_role' : { $type : 2 }}).forEach( function (x) {
  x.your_role = parseInt(x.your_role);
  db.your_collection.save(x);
});
//string转为int类型
db.your_collection.find().forEach( function (x) {
  x.your_role= NumberInt(x.your_role);
  db.your_collection.save(x);
});
//string转化为date类型
db.your_collection.find().forEach( function (x) {
 x.your_role = new ISODate(x.your_role);
  db.your_collection.save(x);
});
//string转decimal
db.your_collection.find().forEach(function(x) {
    x.your_role = NumberDecimal(Number(x.your_role));
    db.your_collection.save(x);
})
//将其转为string类型
db.your_collection.find({your_role:{$exists:true}}).forEach(function(x){
    x.your_role=new String(x.your_role);
    db.your_collection.save(x);//保存
//更改String类型为Date类型
db.getCollection('your_collection').find({'your_role': {$type:2}}).forEach(
    function(doc){
        db.getCollection('your_collection').update({'_id': doc._id},{$set:{'your_role': new ISODate(doc.your_role)}})
    }
)
or 
db.getCollection('your_collection').find({'your_role': {$type:2}}).forEach(
    function(doc){
        doc.your_role = new ISODate(doc.your_role);
        db.getCollection('your_collection').save(doc);
    }
)
//更改Date类型为String类型
db.getCollection('your_collection').find({"_id" : 416,'your_role':{$type:9}}).forEach( 
    function(x){ 
        x.your_role = x.your_role.toISOString(); 
        db.getCollection('your_collection').save(x); 
    } 
)
//将类型转为str
db.getCollection('your_collection').find({"_id" : 419}).forEach( 
    function(x){ 
        x.your_role = String(x.your_role); 
        db.getCollection('your_collection').save(x); 
    } 
)
//截取字符串长度
db.getCollection('your_collection').find({"_id" : 416,'your_role':{$type:2}}).forEach( 
    function(x){ 
        x.your_role = x.your_role.substr(0,10); 
        db.getCollection('your_collection').save(x); 
    } 
)
//更改Date类型为String类型，并截取字符串长度
db.getCollection('your_collection').find({"_id" : 416,'your_role':{$type:2}}).forEach( 
    function(x){ 
        x.your_role = x.your_role.toISOString().substr(0,10); 
        db.getCollection('your_collection').save(x); 
    } 
)
//把时间类型转为NumberLong的时间戳类型
db.getCollection('your_collection').find({"_id" : 419,'your_role':{$type:9}}).forEach( 
    function(x){ 
        x.your_role = NumberLong(x.your_role.getTime()/1000); 
        db.getCollection('your_collection').save(x); 
    } 
)
//设置字段为int类型，NumberInt(3)，默认是double类型
db.getCollection('your_collection').find({"your_role" : null}).forEach(
   function(item){                
       db.getCollection('your_collection').update({"_id":item._id},{$set:{"your_role":NumberInt(3)}})
   }
)
//修改double类型为int类型
db.getCollection('your_collection').find({'your_role' : { $type : 1 }}).forEach(
    function(x) {  
        x.your_role = NumberInt(x.your_role);
        db.getCollection('your_collection').save(x);  
    }
)
//字符串转为浮点数
db.getCollection('your_collection').find({'your_role': {$type:2}}).forEach(
    function(doc){
        db.getCollection('your_collection').update({'_id': doc._id},{$set:{'your_role': parseFloat(doc.your_role)}})
    }
)
//字符串转为double
db.getCollection('your_collection').find({'your_role': {$type:2}}).forEach(
    function(doc){
        db.getCollection('your_collection').update({'_id': doc._id},{$set:{'your_role': parseInt(doc.your_role)}})
    }
)