CRUD Operations

CRUD of Object

If the value of the primary key is already known, Read, Insert, Update, Delete can be used to manipulate the object.

o := orm.NewOrm()
user := new(User)
user.Name = "slene"

fmt.Println(o.Insert(user))

user.Name = "Your"
fmt.Println(o.Update(user))
fmt.Println(o.Read(user))
fmt.Println(o.Delete(user))

To query the object by conditions see Query in advance

Read

o := orm.NewOrm()
user := User{Id: 1}

err := o.Read(&user)

if err == orm.ErrNoRows {
	fmt.Println("No result found.")
} else if err == orm.ErrMissPK {
	fmt.Println("No primary key found.")
} else {
	fmt.Println(user.Id, user.Name)
}

Read uses primary key by default. But it can use other fields as well:

user := User{Name: "slene"}
err := o.Read(&user, "Name")
...

Other fields of the object are set to the default value according to the field type.

For detailed single object query, see One

ReadOrCreate

Try to read a row from the database, or insert one if it doesn’t exist.

At least one condition field must be supplied, multiple condition fields are also supported.

o := orm.NewOrm()
user := User{Name: "slene"}
// Three return values：Is Created，Object Id，Error
if created, id, err := o.ReadOrCreate(&user, "Name"); err == nil {
	if created {
		fmt.Println("New Insert an object. Id:", id)
	} else {
		fmt.Println("Get an object. Id:", id)
	}
}

Insert

The first return value is auto inc Id value.

o := orm.NewOrm()
var user User
user.Name = "slene"
user.IsActive = true

id, err := o.Insert(&user)
if err == nil {
	fmt.Println(id)
}

After creation, it will assign values for auto fields.

InsertMulti

Insert multiple objects in one api.

Like sql statement:

insert into table (name, age) values("slene", 28),("astaxie", 30),("unknown", 20)

The 1st param is the number of records to insert in one bulk statement. The 2nd param is models slice.

The return value is the number of successfully inserted rows.

users := []User{
	{Name: "slene"},
	{Name: "astaxie"},
	{Name: "unknown"},
	...
}
successNums, err := o.InsertMulti(100, users)

When bulk is equal to 1, then models will be inserted one by one.

Update

The first return value is the number of affected rows.

o := orm.NewOrm()
user := User{Id: 1}
if o.Read(&user) == nil {
	user.Name = "MyName"
	if num, err := o.Update(&user); err == nil {
		fmt.Println(num)
	}
}

Update updates all fields by default. You can update specified fields:

// Only update Name
o.Update(&user, "Name")
// Update multiple fields
// o.Update(&user, "Field1", "Field2", ...)
...

For detailed object update, see One

Delete

The first return value is the number of affected rows.

o := orm.NewOrm()
if num, err := o.Delete(&User{Id: 1}); err == nil {
	fmt.Println(num)
}

Delete will also manipulate reverse relationships. E.g.: Post has a foreign key to User. If on_delete is set to cascade, Post will be deleted while delete User.

After deleting, it will clean up values for auto fields.

Changed in 1.0.3 After deleting, it will not clean up values for auto fields.