examples/ogx/example/rel-join-condition/main.go

108 lines
2.5 KiB
Go

package main
import (
"context"
"database/sql"
"fmt"
"gitee.com/chentanyang/ogx"
"gitee.com/chentanyang/ogx/dialect/ogdialect"
"gitee.com/chentanyang/ogx/extra/ogxdebug"
_ "gitee.com/opengauss/openGauss-connector-go-pq"
)
type Profile struct {
ID int64 `ogx:",pk,autoincrement"`
Lang string
Active bool
UserID int64
}
// User has many profiles.
type User struct {
ID int64 `ogx:",pk,autoincrement"`
Name string
Profiles []*Profile `ogx:"rel:has-many,join:id=user_id,join_on:active IS TRUE"`
}
func main() {
ctx := context.Background()
connStr := "host=192.168.20.40 port=26000 user=cuih password=Gauss@123 dbname=test sslmode=disable"
opengaussdb, err := sql.Open("opengauss", connStr)
if err != nil {
panic(err)
}
db := ogx.NewDB(opengaussdb, ogdialect.New())
defer db.Close()
db.AddQueryHook(ogxdebug.NewQueryHook(ogxdebug.WithVerbose(true)))
if err := createSchema(ctx, db, (*User)(nil), (*Profile)(nil)); err != nil {
panic(err)
}
// defer func() {
// _ = dropSchema(ctx, db, (*User)(nil), (*Profile)(nil))
// }()
user := new(User)
if err := db.NewSelect().
Model(user).
Column("user.*").
Relation("Profiles", func(q *ogx.SelectQuery) *ogx.SelectQuery {
return q.Where("lang = 'ru'")
}).
OrderExpr("\"user\".id ASC").
Limit(1).
Scan(ctx); err != nil {
panic(err)
}
fmt.Printf("user.ID: %d, user.Name: %q\n", user.ID, user.Name)
fmt.Printf("user.Profiles: ")
for _, p := range user.Profiles {
fmt.Printf("%v, ", p)
}
fmt.Println()
// Output: user.ID: 1, user.Name: "user 1"
// user.Profiles: &{2 ru true 1},
}
func createSchema(ctx context.Context, db *ogx.DB, models ...interface{}) error {
for _, model := range models {
if _, err := db.NewCreateTable().Model(model).Exec(ctx); err != nil {
return err
}
}
users := []*User{
{ID: 1, Name: "user 1"},
{ID: 2, Name: "user 2"},
}
if _, err := db.NewInsert().Model(&users).Exec(ctx); err != nil {
return err
}
profiles := []*Profile{
{ID: 1, Lang: "en", Active: true, UserID: 1},
{ID: 2, Lang: "ru", Active: true, UserID: 1},
{ID: 3, Lang: "ru", Active: false, UserID: 1},
{ID: 4, Lang: "md", Active: false, UserID: 1},
}
if _, err := db.NewInsert().Model(&profiles).Exec(ctx); err != nil {
return err
}
return nil
}
func dropSchema(ctx context.Context, db *ogx.DB, models ...interface{}) error {
for _, model := range models {
if _, err := db.NewDropTable().Model(model).IfExists().Cascade().Exec(ctx); err != nil {
return err
}
}
return nil
}