I am trying to use https://github.com/astaxie/beego/tree/master/orm to insert a struct into a postgres database. The operation should be simple
import "github.com/astaxie/beego/orm"
type Product struct {
ID string `orm:"pk"`
...
}
product := &Product{ID: productID}
_, err := orm.NewOrm().Insert(product)
if err != nil {
log.Fatal(err)
}
I keep getting this; no LastInsertId available whenever the code runs (the insert is otherwise successful) but I get a crash.
I understand is it due to postgresql limitations because I use https://www.github.com/lib/pq driver.
Is there I way to work around this using beego/orm?
If the crash is being caused by your log.Fatal(err), you can avoid this by checking and avoiding it:
_, err := orm.NewOrm().Insert(product)
if err != nil {
if err.Error() == "no LastInsertId available" {
log.Println(err)
} else {
log.Fatal(err)
}
}
Related
Currently I'm working on a project, and I'm looking for a better way to source code.
I wonder What is Different,
func (db *Database) FindData(ctx context.Context, filter *Data) (*Data, error) {
col := db.client.Database(DefaultDatabase).Collection(COLLECTION_DATA)
var data Data
err := col.FindOne(ctx, filter).Decode(&data)
if err != nil {
return nil, err
}
return &data, nil
}
and
func (db *Database) FindData(ctx context.Context, filter *Data) (*Data, error) {
col := db.client.Database(DefaultDatabase).Collection(COLLECTION_DATA)
res := col.FindOne(ctx, filter)
if err:= res.Err(); err != nil {
return nil, err
}
var data Data
err := res.Decode(&reason)
return &data, err
}
What are the possible differences, and which code is better?
I verified that both sources were the same, and realized that I didn't have to use the long version.
There is no need to implement ERROR processing because ERROR processing of the corresponding result is carried out in Decode().
Thanks for Comment :) Burak Serdar
I am expected to have 80% test coverage even for pushing the basic project structure. I am a bit confused how do I write unit tests for the following code to Connect to postgres db and ping postgres for health check. Can someone help me please.
var postgres *sql.DB
// ConnectToPostgres func to connect to postgres
func ConnectToPostgres(connStr string) (*sql.DB, error) {
db, err := sql.Open("postgres", connStr)
if err != nil {
log.Println("postgres-client ", err)
return nil, err
}
postgres = db
return db, nil
}
// PostgresHealthCheck to ping database and check for errors
func PostgresHealthCheck() error {
if err := postgres.Ping(); err != nil {
return err
}
return nil
}
type PostgresRepo struct {
db *sql.DB
}
// NewPostgresRepo constructor
func NewPostgresRepo(database *sql.DB) *PostgresRepo {
return &PostgresRepo{
db: database,
}
}
You need to use this : https://github.com/DATA-DOG/go-sqlmock
Its very easy to use. Here is an example where a controller is getting tested using a mocked SQL :
Implementation
func (up UserProvider) GetUsers() ([]models.User, error) {
var users = make([]models.User, 0, 10)
rows, err := up.DatabaseProvider.Query("SELECT firstname, lastname, email, age FROM Users;")
if err != nil {
return nil, err
}
for rows.Next() {
var u models.User = models.User{}
err := rows.Scan(&u.Name, &u.Lastname, &u.Email, &u.Age)
if err != nil {
return nil, err
}
users = append(users, u)
}
if err := rows.Err(); err != nil {
return nil, err
}
return users, nil
}
Test
func TestGetUsersOk(t *testing.T) {
db, mock := NewMock()
mock.ExpectQuery("SELECT firstname, lastname, email, age FROM Users;").
WillReturnRows(sqlmock.NewRows([]string{"firstname", "lastname", "email", "age"}).
AddRow("pepe", "guerra", "pepe#gmail.com", 34))
subject := UserProvider{
DatabaseProvider: repositories.NewMockDBProvider(db, nil),
}
resp, err := subject.GetUsers()
assert.Nil(t, err)
assert.NotNil(t, resp)
assert.Equal(t, 1, len(resp))
}
func NewMock() (*sql.DB, sqlmock.Sqlmock) {
db, mock, err := sqlmock.New()
if err != nil {
log.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
}
return db, mock
}
I find that writing tests against a live database makes for more high quality tests. The challenge with Postgres is that there's no good in-memory fake that you can substitute in.
What I came up with is standing up the postgres Docker container and creating temporary databases in there. The PostgresContainer type in the github.com/bitcomplete/sqltestutil package does exactly this:
# Postgres version is "12"
pg, _ := sqltestutil.StartPostgresContainer(context.Background(), "12")
defer pg.Shutdown(ctx)
db, err := sql.Open("postgres", pg.ConnectionString())
// ... execute SQL
Per the docs, it's a good idea to set up your tests so that the container is only started once, as it can take a few seconds to start up (more if the image needs to be downloaded). It suggests some approaches for mitigating that problem.
I am trying to create a function that InsertOne data by wrap transaction, and I already to replica set in mongodb also, I tried in local and and MongoDB atlas the error were same,
here is the code:
const MONGODB_URI = "mongodb://localhost:27017,localhost:27018,localhost:27019/?replicaSet=rs"
ctx := context.Background()
client, err := mongo.Connect(ctx, options.Client().ApplyURI(MONGODB_URI))
if err != nil {
panic(err)
}
db := client.Database("production")
defer db.Client().Disconnect(ctx)
col := db.Collection("people")
// transaction
err = db.Client().UseSession(ctx, func(sessionContext mongo.SessionContext) error {
err := sessionContext.StartTransaction()
if err != nil {
fmt.Println(err)
return err
}
_, err = col.InsertOne(sessionContext, req)
if err != nil {
sessionContext.AbortTransaction(sessionContext)
fmt.Println(err)
return err
} else {
sessionContext.CommitTransaction(sessionContext)
}
return nil
})
if err != nil {
return nil, err
}
I have follow the instructions of this question in Stackoverflow and I have tried also ways from this article mongodb developer
what I got is this error:
(NamespaceNotFound) Cannot create namespace
production.people in multi-document transaction.
and
multiple write errors: [{write errors:
[{Cannot create namespace spura.people in multi-document transaction.}]},
{<nil>}]"
it got error when I inserted data , is that something wrong in my code? I have tried look carefully and try the instruction of document or articles and always got that error :(
MongoDB 4.2 and lower does not permit creating collections in transactions. This restriction is lifted in 4.4.
For 4.2 and lower, create the collection ahead of time.
I am getting the data of an account using the ID of it. Currently, when I make this query the mongo-go-driver gives an error and I want to handle this error differently, depending on its type. For example if the document doesn't exist I want to return a 404 but lets suppose that the instance holding my mongodb falls, in this case I want to return a 500. How can I handle the error type:
func (dao MongoDAO) Get(ctx *gin.Context, filter bson.M, entity interface{}) error {
context, _ := context.WithTimeout(context.Background(), 5*time.Second)
if err := dao.Collection.FindOne(context, filter).Decode(entity); err != nil {
return err
}
return nil
}
You could use the Error variables defined in the mongo-go-driver docs (https://pkg.go.dev/go.mongodb.org/mongo-driver/mongo?tab=doc#pkg-variables). With these you might be able to do something like this:
func (dao MongoDAO) Get(ctx *gin.Context, filter bson.M, entity interface{}) error {
context, _ := context.WithTimeout(context.Background(), 5*time.Second)
if err := dao.Collection.FindOne(context, filter).Decode(entity); err != nil {
if err == mongo.ErrNoDocuments {
// Return the 404
}
return err
}
return nil
}
I'm brand new to Go, and I've started working on some postgres queries, and I'm having very little luck.
I have a package that's just going to have some database queries in it. Here's my code.
main.go
package main
import (
"fmt"
)
func main() {
fmt.Println("Querying data")
myqueries.SelectAll("mytable")
}
myqueries.go
package myqueries
import (
"database/sql"
"fmt"
)
func SelectAll (table string) {
db, err := sql.Open("postgres","user=postgres dbname=mydb sslmode=disable")
if err != nil {
fmt.Println(err)
}
defer db.Close()
rows, err := db.Query("SELECT * FROM $1", table)
if err != nil {
fmt.Println(err)
} else {
PrintRows(rows)
}
}
func PrintRows(rows *sql.Rows) {
for rows.Next() {
var firstname string
var lastname string
err := rows.Scan(&firstname, &lastname)
if err != nil {
fmt.Println(err)
}
fmt.Println("first name | last name")
fmt.Println("%v | %v\n", firstname, lastname)
}
}
The error I get is pq: syntax error at or near "$1"
which is from myqueries.go file in the db.Query.
I've tried several variations of this, but nothing has worked yet. Any help is appreciated.
It looks like you are using https://github.com/lib/pq based on the error message and it's docs say that
pq uses the Postgres-native ordinal markers, as shown above
I've never known a database engine that allows the parameterized values in anything other than values. I think you are going to have to resort to string concatenation. I don't have a Go compiler available to me right now, but try something like this. Because you are inserting the table name by concatination, you need it sanitized. pq.QuoteIdentifier should be able to help with that.
func SelectAll (table string) {
db, err := sql.Open("postgres","user=postgres dbname=mydb sslmode=disable")
if err != nil {
fmt.Println(err)
}
defer db.Close()
table = pq.QuoteIdentifier(table)
rows, err := db.Query(fmt.Sprintf("SELECT * FROM %v", table))
if err != nil {
fmt.Println(err)
} else {
PrintRows(rows)
}
}
EDIT: Thanks to hobbs to pointing out pq.QuoteIdentifier