README
¶
gmgo
Convenient wrapper around Go's MongoDB driver Mgo
Usage:
package main
import (
"fmt"
"github.com/narup/gmgo"
"log"
)
var userDB gmgo.Db
####################
type User struct {
Name string `json:"name" bson:"name"`
Email string `json:"email" bson:"email"`
}
// Each of your data model that needs to be persisted should implment gmgo.Document interface
func (user User) CollectionName() string {
return "user"
}
####################
func saveNewUser() {
session := userDB.Session()
defer session.Close()
user := &User{Name:'Puran', Email:'puran@xyz.com'}
user.Id = bson.NewObjectId()
userId, err := session.Save(user)
if err != nil {
log.Fatalf("Error saving user : %s.\n", err)
}
fmt.Printf("User id %s", userId)
}
func findUser(userId string) *User {
session := userDB.Session()
defer session.Close()
user := new(User)
if err := session.FindByID(userId, user); err != nil {
return nil
}
return user
}
//Find all users
func findAllUsers() {
session := userDB.Session()
defer session.Close()
users, err := session.FindAll(gmgo.Q{}, new(User)) //Note user pointer is passed to identify the collection type etc.
if err != nil {
fmt.Printf("Error fetching users %s", err)
} else {
for _, user := range users {
fmt.Println(user.Name)
}
}
}
func findUsingIterator() ([]*user, error) {
session := testDBSession()
defer session.Close()
users := make([]*user, 0)
itr := session.DocumentIterator(Q{"state": "CA"}, "user")
itr.Load(IteratorConfig{Limit: 20, SortBy: []string{"-_id"}})
result, err := itr.All(new(user))
if err != nil {
println(err)
return
}
users := result.([]*user)
for _, usr := range users {
println(usr.ID.Hex() + " -- " + usr.CreatedDate.String())
}
return users, nil
}
func setupUserDB() {
if userDbErr := gmgo.Setup(gmgo.DbConfig{"localhost:27017", "userdb", "", ""}); userDbErr != nil {
log.Fatalf("Database connection error : %s.\n", userDbErr)
return
}
newDb, userDbErr := gmgo.New("userdb")
if userDbErr != nil {
log.Fatalf("Db connection error : %s.\n", err)
}
userDB = newDb
}
func main() {
//setup Mongo database connection. You can setup multiple db connections
setupUserDB()
user := findUser("56596608e4b07ceddcfad96e")
if user != nil {
fmt.Printf("User name:%s\n", user.Name)
} else {
fmt.Printf("Couldn't find user")
}
findAllUsers()
}
Documentation
¶
Index ¶
- func Setup(dbConfig DbConfig) error
- type Db
- type DbConfig
- type DbSession
- func (s *DbSession) Clone() *DbSession
- func (s *DbSession) Close()
- func (s *DbSession) Collection(d Document) *mgo.Collection
- func (s *DbSession) DocumentIterator(query Q, collection string) *DocumentIterator
- func (s *DbSession) Exists(query Q, document Document) (bool, error)
- func (s *DbSession) Find(query Q, document Document) error
- func (s *DbSession) FindAll(query Q, document Document) (interface{}, error)
- func (s *DbSession) FindAllWithFields(query Q, fields []string, document Document) (interface{}, error)
- func (s *DbSession) FindByID(id string, result Document) error
- func (s *DbSession) FindByRef(ref *mgo.DBRef, document Document) error
- func (s *DbSession) FindWithLimit(limit int, query Q, document Document) (interface{}, error)
- func (s *DbSession) Pipe(pipeline interface{}, document Document) *mgo.Pipe
- func (s *DbSession) ReadFile(id, prefix string, file *File) error
- func (s *DbSession) Remove(query Q, document Document) error
- func (s *DbSession) RemoveAll(query Q, document Document) error
- func (s *DbSession) Save(document Document) error
- func (s *DbSession) SaveFile(file File, prefix string) (string, error)
- func (s *DbSession) Update(selector Q, document Document) error
- func (s *DbSession) UpdateFieldValue(query Q, collectionName, field string, value interface{}) error
- type Document
- type DocumentIterator
- func (pd *DocumentIterator) All(document Document) (interface{}, error)
- func (pd *DocumentIterator) Close() error
- func (pd *DocumentIterator) Error() error
- func (pd *DocumentIterator) FetchNext(d interface{}) bool
- func (pd *DocumentIterator) HasMore() bool
- func (pd *DocumentIterator) IsTimeout() bool
- func (pd *DocumentIterator) Load(cfg IteratorConfig)
- func (pd *DocumentIterator) Next(d Document) error
- type File
- type IteratorConfig
- type MongoTail
- type Q
- type TailEvent
- type TailEventHandler
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Db ¶
type Db struct {
Config DbConfig
// contains filtered or unexported fields
}
Db represents database connection which holds reference to global session and configuration for that database.
type DbSession ¶
DbSession mgo session wrapper
func (*DbSession) Clone ¶
Clone returns the clone of current DB session. Cloned session uses the same socket connection
func (*DbSession) Collection ¶
func (s *DbSession) Collection(d Document) *mgo.Collection
Collection returns a mgo.Collection representation for given document
func (*DbSession) DocumentIterator ¶
func (s *DbSession) DocumentIterator(query Q, collection string) *DocumentIterator
DocumentIterator returns the document iterator which could be used to fetch documents as batch with batch size and other config params
func (*DbSession) FindAllWithFields ¶
func (s *DbSession) FindAllWithFields(query Q, fields []string, document Document) (interface{}, error)
FindAllWithFields returns all the documents with given fields based on a given query
func (*DbSession) FindByID ¶
FindByID find the object by id. Returns error if it's not able to find the document. If document is found it's copied to the passed in result object.
func (*DbSession) FindWithLimit ¶
FindWithLimit find the doucments for given query with limit
func (*DbSession) Save ¶
Save inserts the given document that represents the collection to the database.
type Document ¶
type Document interface {
CollectionName() string
}
Document interface implemented by structs that needs to be persisted. It should provide collection name, as in the database. Also, a way to create new object id before saving.
type DocumentIterator ¶
type DocumentIterator struct {
// contains filtered or unexported fields
}
DocumentIterator is used to iterate over results and also provides a way to configure query using IteractorConfig For example:
session := db.Session()
defer session.Close()
pd := session.DocumentIterator(gmgo.Q{"state":"CA"}, "user")
pd.Load(gmgo.IteratorConfig{PageSize: 200, Snapshot: true})
for pd.HasMore() {
usr := new(user)
result, err := pd.Next(&usr)
if err != nil {
println(err.Error())
return
}
u := result.(*user)
}
func (*DocumentIterator) All ¶
func (pd *DocumentIterator) All(document Document) (interface{}, error)
All returns all the documents in the iterator.
func (*DocumentIterator) Close ¶
func (pd *DocumentIterator) Close() error
Close closes the document iterator
func (*DocumentIterator) Error ¶
func (pd *DocumentIterator) Error() error
Error returns iteration error
func (*DocumentIterator) FetchNext ¶
func (pd *DocumentIterator) FetchNext(d interface{}) bool
FetchNext retrieves the next document from the result set. For more details see mgo.Iter.Next() return false if there are no more records to fetch
Usage:
aitr := session.DocumentIterator(gmgo.Q{}, data.User{}.CollectionName())
aitr.Load(gmgo.IteratorConfig{PageSize: 1000, SortBy: []string{"-_id"}})
var usr *data.User
for aitr.FetchNext(&usr) {
fmt.Printf("ID: %s", usr.Id)
}
//check if error happend
err := aitr.Error()
if err != nil {
fmt.Printf("handle error: %s", err)
}
//check if timeout happened
if aitr.IsTimeOut() {
-- handle timeout
}
func (*DocumentIterator) HasMore ¶
func (pd *DocumentIterator) HasMore() bool
HasMore returns true if paged document has still more documents to fetch. DEPRECATED Use FetchNext in favor of this
func (*DocumentIterator) IsTimeout ¶
func (pd *DocumentIterator) IsTimeout() bool
IsTimeout returns true if the iterator timed out
func (*DocumentIterator) Load ¶
func (pd *DocumentIterator) Load(cfg IteratorConfig)
Load loads the document iterator using IteratorConfig For example: Limit and sort by user full name
itr := session.DocumentIterator(Q{"state": "CA"}, new(user))
itr.Load(IteratorConfig{Limit: 20, SortBy: []string{"fullName"}})
fetch with page size
pd.Load(IteratorConfig{PageSize: 200})
func (*DocumentIterator) Next ¶
func (pd *DocumentIterator) Next(d Document) error
Next returns the next result object in the paged document. If there's no element it will check for error and return the error if there's error. DEPRECATED - Use FetchNext in favor of this
type IteratorConfig ¶
type IteratorConfig struct {
//PageSize is used as a batch size. See mgo.Iter.Batch() for more details.
//Default value used by MongoDB is 100. So, any value less than 100 is ignored
PageSize int
//Limit used limit the number of documents
Limit int
//Snashopt ($snapshot) operator prevents the cursor from returning a document more than
//once because an intervening write operation results in a move of the document.
Snapshot bool
//SortBy list of field names to sort the result
SortBy []string
}
IteratorConfig defines different iterator config to load the document interator
type MongoTail ¶
type MongoTail struct {
EventHandler TailEventHandler
ReImport bool
}
MongoTail handles MongoDB tailing event coordination and also update destination dbs
Source Files
Directories