I'm doing a tiny project(practice) with revel and mgo, but I got something wrong with search function when I build the queries. The code seems like this:
conditions := make(bson.M, 0)
conditions["status"] = bson.M{"$ne": "delete"}
if item, ok := paramsPost["title"]; ok {
if item[0] != "" {
conditions["title"] = bson.RegEx{Pattern: item[0]}
}
}
if item, ok := paramsPost["from_date"]; ok {
if item[0] != "" {
conditions["publishdate"] = bson.M{}
fromDate, _ := time.Parse("2006-01-02", item[0])
conditions["publishdate"]["$gte"] = fromDate.Unix()
}
}
if item, ok := paramsPost["to_date"]; ok {
if _, ok := conditions["publishdate"]; !ok {
conditions["publishdate"] = bson.M{}
}
if item[0] != "" {
toDate, _ := time.Parse("2006-01-02", item[0])
conditions["publishdate"]["$lte"] = toDate.Unix()
}
}
And I got some error info:
invalid operation: conditions["publishdate"]["$gte"] (index of type interface {})
I know I make something wrong, but I don't know why, and how to resolve. Anybody can help me? Thanks
bson.M
is a map[string]interface{}
(http://godoc.org/labix.org/v2/mgo/bson#M)
So, in
conditions["publishdate"]["$gte"] = fromDate.Unix()
You need to do a type assertion from interface{}
to bson.M
when looking up publishdate
in the map.
Instead, you could refactor the code to something like
publishdate:= bson.M{}
// ... your logic goes here
conditions["publishdate"] = publishDate
to save on unnecessary map lookups and type assertions.