Object-Relational Mapping (ORM) is a technique that lets you query and manipulate data from a database using an object-oriented paradigm.
This ORM works hand to hand with DALgo DAL.
Firs of all you need to define fields of your data objects:
package schema
import (
"github.com/strongo/dalgo/dal"
"github.com/strongo/dalgo/orm"
)
type UserFields struct {
Email orm.FieldDefinition[string]
FirstName orm.FieldDefinition[string]
LastName orm.FieldDefinition[string]
}
type UserCollection struct {
Fields UserFields
}
func (v UserCollection) CollectionRef() dal.CollectionRef {
return dal.CollectionRef{Name: "Users"}
}
// This will be used to query data
var Users = UserCollection{
Fields: UserFields{
Email: orm.NewFieldDefinition("email", orm.KindString),
FirstName: orm.NewFieldDefinition("first_name", orm.KindString),
LastName: orm.NewFieldDefinition("last_name", orm.KindString),
},
} Now you can create queries to database using strongly typed code.
For example imaging we'd like to select a user with specific email:
package example
import (
"github.com/strongo/dalgo/dal"
"github.com/strongo/dalgo/orm"
)
func QueryUserIDByEmail(email string) *dal.Query {
return schema.Users.Query().
Where(schema.Users.Field.Email.EqualTo("test@example.com")).
Limit(1).
SelectKeysOnly(schema.Users.IDKind())
}