// Get reteives a record given the id
func Get(collectionName, id string) (*map[string]interface{}, error) {
connection := shared.Connection()
if connection == nil {
return nil, errors.New("No connection to database server")
}
var result map[string]interface{}
collection := connection.DB(variables.DBName).C(collectionName)
if !bson.IsObjectIdHex(id) {
return nil, errors.New("Invalid id: " + id)
}
err := collection.FindId(bson.ObjectIdHex(id)).One(&result)
if err != nil {
return nil, err
}
return &result, nil
}
// Index creates an index on an a collection
func Index(collectionName, key, indexType string) error {
connection := shared.Connection()
if connection == nil {
return errors.New("No connection to database server")
}
collection := connection.DB(variables.DBName).C(collectionName)
setIndex := fmt.Sprintf("$%s:%s", indexType, key)
// Define the index
index := mgo.Index{
Key: []string{setIndex},
}
// Apply the index
return collection.EnsureIndex(index)
}
// Near reteives records near the given longitude and latitude
func Near(collectionName string, longitude, latitude, radius float64) (*map[string]interface{}, error) {
connection := shared.Connection()
if connection == nil {
return nil, errors.New("No connection to database server")
}
collection := connection.DB(variables.DBName).C(collectionName)
setIndex := fmt.Sprintf("$%s:%s", "2dsphere", "location")
// Define the index
index := mgo.Index{
Key: []string{setIndex},
}
// Apply the index
err := collection.EnsureIndex(index)
if err != nil {
log.Println("ERROR creating 2dsphere index", err)
}
var found []map[string]interface{}
err = collection.Find(bson.M{
"location": bson.M{
"$nearSphere": bson.M{
"$geometry": bson.M{
"type": "Point",
"coordinates": []float64{longitude, latitude},
},
"$maxDistance": radius,
},
},
}).All(&found)
if err != nil {
return nil, err
}
result := map[string]interface{}{
"rows": found,
}
return &result, nil
}