The fantastic ORM library for Golang, aims to be developer friendly, check http://gorm.io/community.html#Ask before ask
func SetupDB() (*gorm.DB, error) {
LoadDBConfig()
if DB != nil {
return DB, nil
}
connectionString := DBConfig.DB_User + ":" + DBConfig.DB_Pass + "@tcp(" + DBConfig.DB_Host + ")/" + DBConfig.DB_Name + "?charset=utf8&parseTime=True&loc=Local" //nolint:wsl,lll
var err error //nolint:wsl
// Connect again with DB name.
DB, err = gorm.Open(DBConfig.DB_Driver, connectionString)
if err != nil {
return nil, err
}
DB.DB().SetMaxOpenConns(100)
DB.DB().SetMaxIdleConns(100)
DB.DB().SetConnMaxLifetime(5 * time.Minute)
return DB, nil //nolint:wsl
}
Hi, I have created a relationship between a campaign and a []customers. I can create an entry in the psql db and attach customers when I db.Save() however how do I add relationships later when my frontend sends the ID of the campaign and the IDs of the customers.
I have tried:
func UpdateCustomersForCampaignByIds(cId uint, ids []uint) error {
var c Campaign
if err := db.Debug().Where("id=?", cId).Preload("Customers", "id IN (?)", ids).Update(&c).Error; err != nil {
return err
}
return nil
}however I get nothing entered into the foreign-key table when I call it with
customerIds := []uint{1}
database.UpdateCustomersForCampaignByIds(4, customerIds)Thanks!
Could anyone just point me to the right direction or tell me it is not possible? I use simple preloads with
db.Preload("Countries").Find(&towns)It works great. However, I would like to do the same using JOINs, instead of SELECT and then SELECT WHERE IN. Is it possible? I found out GORM isn't willing to load fields of the inner struct (Country in this case) without having it mentioned in the Preload, however it always makes a SELECT WHERE IN if you include it in the Preload, no matter what other columns have already been selected
db.Model(&parent).Association("Remarks").Append(newRemark)
ID int64
gorm:"primary_key" json:"id"EduID1 int64
json:"exp_id1" gorm:"index:edu1;index:edu1_user1;index:edu1_user2"EduID2 int64
json:"exp_id2" gorm:"index:edu2;index:edu2_user1;index:edu2_user2"UserID1 int64
json:"user_id1" gorm:"index:user_id1;index:edu1_user1;index:edu2_user1"UserID2 int64
json:"user_id2" gorm:"index:user_id2;index:edu1_user2;index:edu2_user2"
CREATE INDEX edu1_user2 ON
user_classmate(edu_id1) [] 0CREATE INDEX edu2_user2 ON
user_classmate(edu_id2, user_id2) [] 0CREATE INDEX edu2_user1 ON
user_classmate(user_id1) [] 0
I'm wondering how this piece of code:
sqlDB, err := DB.DB()
sqlDB.SetMaxOpenConns(100)
sqlDB.SetMaxIdleConns(100)
sqlDB.SetConnMaxLifetime(5 * time.Minute)
return DB, nilwill ensure the MaxOpenConnections and IdleConnection on DB.DB() because the settings are defined for sqlDB which is a new variable
I tried to implement GormV2 with SetMaxOpenConns and SetMaxIdleConns using following code
var DB *gorm.DB
func SetupDB() (*gorm.DB, error) {
//nolint:wsl,lll
var err error //nolint:wsl
LoadDBConfig()
connectionString := ""
if DB != nil {
return DB, nil
}
switch DBConfig.DB_Driver {
case "postgres":
connectionString = fmt.Sprintf("host=%s port=%d user=%s dbname=%s password=%s", DBConfig.DB_Host, DBConfig.DB_Port, DBConfig.DB_User, DBConfig.DB_Name, DBConfig.DB_Pass)
DB, err = gorm.Open(postgres.Open(connectionString), &gorm.Config{})
default:
connectionString = fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8&parseTime=True&loc=Local", DBConfig.DB_User, DBConfig.DB_Pass, DBConfig.DB_Host, DBConfig.DB_Port, DBConfig.DB_Name)
DB, err = gorm.Open(mysql.Open(connectionString), &gorm.Config{})
}
if err != nil {
panic(err)
}
sqlDB, err := DB.DB()
sqlDB.SetMaxOpenConns(100)
sqlDB.SetMaxIdleConns(100)
sqlDB.SetConnMaxLifetime(5 * time.Minute)
return DB, nil //nolint:wsl
}
func GetUserByEmail(email string) (*User, error) {
var user User
if err := DB.Where(&User{Email: email}).First(&user).Error; err != nil {
return nil, err
}
return &user, nil //nolint:wsl
}Getting following error when trying to do a load test:
failed to connect to `host=localhost user=postgres database=casbin`: server error (FATAL: sorry, too many clients already (SQLSTATE 53300))What am I missing in above code?
What am I doing wrong while trying to preload data?db.Debug().Preload("Disposal").Where("project_id = ?", c.Param("id")).Find(&projects)
My Project model:
// Project struct is used to store all relevant information
type Project struct {
ProjectID uint `gorm:"primary_key" json:"ProjectID"`
Name string `json:"Name"`
Disposals []Disposal
Supplies []Supply
}My Disposal model:
// Disposal struct is used to store all relevant information
type Disposal struct {
DisposalID uint `gorm:"primary_key" json:"DisposalID"`
Depository Depository `gorm:"foreignkey:DepositoryRefer" json:"Depository"`
DepositoryRefer uint
Material Material `gorm:"foreignkey:MaterialRefer" json:"Material"`
MaterialRefer uint
Date time.Time `json:"Date"`
Measurement float64 `json:"Measurement"`
Project Project `gorm:"foreignkey:ProjectRefer;AssociationForeignKey:project_id" json:"Project"`
ProjectRefer uint
}The foreign keys I've set:
db.Model(Disposal{}).AddForeignKey("depository_refer", "depositories(depository_id)", "RESTRICT", "RESTRICT")
db.Model(Disposal{}).AddForeignKey("material_refer", "materials(material_id)", "RESTRICT", "RESTRICT")
db.Model(Disposal{}).AddForeignKey("project_refer", "projects(project_id)", "RESTRICT", "RESTRICT")
Are there known issues with using associations? I have had a lot of trouble getting GORM to create associations consistently.
Also, is there a standard or guide as to when we would need to create associations as pointers vs not? Does adding a json tag affect an association?
db.Debug().Table("profile").
Joins("JOIN address ON address.uid = profile.uid").
Where("profile.uid = ?", uid). Find(&profileStruct) This query returns only fields belonging to the profile table, although i am expecting fields from both tables. Any help will be really appreciated. Thank you.
