Basic Usage

Use existing MongoDB connection, or setup a new one to register a default database connection.

For existing database connection,

import "github.com/Lyearn/mgod"

func init() {
	// client is the MongoDB client obtained using Go Mongo Driver's Connect method.
	mgod.SetDefaultClient(client)
}

To setup a new connection,

import (
	"time"

	"github.com/Lyearn/mgod"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func init() {
	// `cfg` is optional. Can rely on default configurations by providing `nil` value in argument.
	cfg := &mgod.ConnectionConfig{Timeout: 5 * time.Second}
	opts := options.Client().ApplyURI("mongodb://root:mgod123@localhost:27017")

	err := mgod.ConfigureDefaultClient(cfg, opts)
}

note

The above err variable will be a connection error (if occurs) returned by the Go Mongo Driver. So, handle the error accordingly.

Add tags (wherever applicable) in existing struct (or define a new model).

type User struct {
	Name     string
	EmailID  string `bson:"emailId"`
	Age      *int32 `bson:",omitempty"`
	JoinedOn string `bson:"joinedOn" mgoType:"date"`
}

Use mgod to get the entity ODM.

import (
	"github.com/Lyearn/mgod"
	"github.com/Lyearn/mgod/schema/schemaopt"
)

model := User{}
dbName := "mgoddb"
collection := "users"

schemaOpts := schemaopt.SchemaOptions{
	Timestamps: true,
}

opts := mgod.NewEntityMongoModelOptions(dbName, collection, &schemaOpts)
userModel, _ := mgod.NewEntityMongoModel(model, *opts)

Use the entity ODM to perform CRUD operations with ease.

Inserting a new document

joinedOn, _ := dateformatter.New(time.Now()).GetISOString()
userDoc := User{
	Name: "Gopher",
	EmailID: "gopher@mgod.com",
	JoinedOn: joinedOn,
}
user, _ := userModel.InsertOne(context.TODO(), userDoc)

Output:

{
	"_id": ObjectId("65697705d4cbed00e8aba717"),
	"name": "Gopher",
	"emailId": "gopher@mgod.com",
	"joinedOn": ISODate("2023-12-01T11:32:19.290Z"),
	"createdAt": ISODate("2023-12-01T11:32:19.290Z"),
	"updatedAt": ISODate("2023-12-01T11:32:19.290Z"),
	"__v": 0
}

Notice how _id, createdAt, updatedAt and __v fields are added automatically.

Finding documents using model properties

users, _ := userModel.Find(context.TODO(), bson.M{"name": userDoc.Name})

Output:

[]User{
	User{
		Name: "Gopher",
		EmailID: "gopher@mgod.com",
		JoinedOn: "2023-12-01T11:32:19.290Z",
	}
}

Updating document properties

result, _ := userModel.UpdateMany(context.TODO(), bson.M{"joinedOn": bson.M{"$gte": "2023-12-01T00:00:00.000Z"}}, bson.M{"$inc": {"__v": 1}})

Output:

mongo.UpdateResult{
	MatchedCount: 1,
	ModifiedCount: 1,
	UpsertedCount: 0,
}

// User Doc
{
	"_id": ObjectId("65697705d4cbed00e8aba717"),
	"name": "Gopher",
	"emailId": "gopher@mgod.com",
	"joinedOn": ISODate("2023-12-01T11:32:19.290Z"),
	"createdAt": ISODate("2023-12-01T11:32:19.290Z"),
	"updatedAt": ISODate("2023-12-02T10:40:00.670Z"),
	"__v": 1
}

Notice the updation of the updatedAt field.

Removing documents matching certain or all model properties

result, _ := userModel.DeleteMany(context.TODO(), bson.M{"name": userDoc.Name})

Output:

mongo.DeleteResult{
	DeletedCount: 1
}