如何使用mgo和Go查询日期范围的MongoDB？

Question

Hi I have a collection named "my_sales" having fields product_name, price, sale_date.

My doc looks like

{
    "_id" : ObjectId("5458b6ee09d76eb7326df3a4"),
    "product_name" : product1,
    "price" : 200,
    "sale_date" : ISODate("2014-11-04T11:22:19.589Z")
}
{
    "_id" : ObjectId("5458b6ee09d76eb7326df3a4"),
    "product_name" : product1,
    "price" : 200,
    "sale_date" : ISODate("2014-11-04T11:22:19.589Z")
}
{
    "_id" : ObjectId("5458b6ee09d76eb7326df3a4"),
    "product_name" : product1,
    "price" : 200,
    "sale_date" : ISODate("2014-11-04T11:22:19.589Z")
}
{
    "_id" : ObjectId("5458b6ee09d76eb7326df3a4"),
    "product_name" : product1,
    "price" : 200,
    "sale_date" : ISODate("2014-11-05T11:22:19.589Z")
}

I tried in mongo shell like this

 db.my_sales.find({ sale_date: { $gt: ISODate("2014-11-04"), $lt: new ISODate("2014-11-05") });

It giving the correct result. Now I need to query same thing using golang I tried like this

 var sales_his []Sale
 err := c.Find(bson.M{"sale_date":bson.M{ "$gt": "ISODate("+date_from+")", "$lt": "ISODate("+date_to+")" }    }).All(&sales_his)

Its giving null result please help

Answer 1

mgo supports time.Time for BSON dates.

So if your struct looks like this:

type Sale struct {
    ProductName string    `bson:"product_name"`
    Price       int       `bson:"price"`
    SaleDate    time.Time `bson:"sale_date"`
}

Then you can query it like this:

fromDate := time.Date(2014, time.November, 4, 0, 0, 0, 0, time.UTC)
toDate := time.Date(2014, time.November, 5, 0, 0, 0, 0, time.UTC)

var sales_his []Sale
err = c.Find(
    bson.M{
        "sale_date": bson.M{
            "$gt": fromDate,
            "$lt": toDate,
        },
    }).All(&sales_his)