go-gpa

README

go-gpa

GPA - Golang Persistence API / Golang ORM / Golang Database / Generics

Working with:

Postgres

Idea:

The idea of this library is to make developers life much more easier and provide more quick development, at least for starting projects.

If you not have initialized table previously orm.From[Entity]() method will initialize table automatically.

Usage:

Entity initializations:

// mappedBy - field ID in the table to which joining
// fetchBy - field ID which should be joined with Role entity table (roles); 
//      field ID from structure table
// join - table name to which should be joined mappedBy ID
//
// User GPA entity
type User struct {
    ID    int64   `db:"id"`
    Name  string  `db:"name"`
    Roles *[]Role `join:"user_roles" fetchBy:"role_id" mappedBy:"user_id" fetch:"lazy"`
}

func (u User) String() string {
    return fmt.Sprintf("{%d %s %+v}\n", u.ID, u.Name, u.GetRoles())
}

func (u User) GetRoles() []Role {
    if u.Roles != nil {
        return *u.Roles
    }
    return []Role{}
}

// Role GPA entity
type Role struct {
    ID   int64  `db:"id"`
    Name string `db:"name"`
}

// UserRole GPA entity
type UserRole struct {
    Role interface{} `db:"role_id" join:"roles" mappedBy:"id" fetch:"lazy"`
    User interface{} `db:"user_id" join:"users" mappedBy:"id"`
}

// GPAConfigure method where could be provided configs for GPAEntity, for ex. custom table name
func (d UserRole) GPAConfigure(o *gpa.Engine) {
    o.SetTableName(d, "user_roles")
}

ORM initialization:

// Global initialization go-gpa Engine
cfg := gpa.Config{IsLazy: false}
gpa.NewEngine(DB, cfg)

// If used lazy fetch type, 
// structures should be initialized manually
// cfg := gpa.Config{IsLazy: true}
// gpa.From[UserRole]()
// gpa.From[Role]()

Api examples:

// Save data to DB
err := gpa.From[User]().Insert(User{
    Name: "John",
})

// Update data in DB
err := gpa.From[User]().Update(User{ID: id, Name: "Doe"})

// Find all Data from DB
users, err := gpa.From[User]().FindAll(nil) // could be added pagination

// Find Data from DB by ID
user, err := gpa.From[User]().FindByID(id)

// Insert array of data
err := gpa.From[Document]().Inserts([]Document{
    {Text: "doc1", Title: "some text", Views: 11},
    {Text: "doc2", Title: "some text 2", Views: 67},
});

// Finding by conditions with filters
docs, err := gpa.From[Document]().FindBy([]gpa.F{
    {FieldName: "title", Sign: gpa.Equal, Value: "doc1", Cond: gpa.OR},
    {FieldName: "views", Sign: gpa.More, Value: 10},
}, nil)

// Find One By custom filter
roleAdmin, err := gpa.From[Role]().FindOneBy([]gpa.F{{FieldName: "name", Sign: gpa.Equal, Value: "ADMIN"}}, nil)

// Custom selecting with sqlx
_, err := gpa.From[Document]().Select("title = $1", "hellotext")

// Custom getting by sqlx
_, err := gpa.From[Document]().Get("views >= $1", 10)

// Remove Data from DB
err := gpa.From[User]().Delete(user.ID);

// Get Lazy User with Roles
userWithRoles, err := gpa.From[User]().FindByID(1)
userWithRoles.GetRoles()