examples/ogx/example/rel-has-many-polymorphic/main.go

104 lines
2.2 KiB
Go

package main
import (
"context"
"database/sql"
"os"
"github.com/davecgh/go-spew/spew"
"gitee.com/chentanyang/ogx"
"gitee.com/chentanyang/ogx/dbfixture"
"gitee.com/chentanyang/ogx/dialect/ogdialect"
"gitee.com/chentanyang/ogx/extra/ogxdebug"
_ "gitee.com/opengauss/openGauss-connector-go-pq"
)
type Comment struct {
TrackableID int64 // Article.ID or Post.ID
TrackableType string // "article" or "post"
Text string
}
type Article struct {
ID int64 `ogx:",pk,autoincrement"`
Name string
Comments []Comment `ogx:"rel:has-many,join:id=trackable_id,join:type=trackable_type,polymorphic"`
}
type Post struct {
ID int64 `ogx:",pk,autoincrement"`
Name string
Comments []Comment `ogx:"rel:has-many,join:id=trackable_id,join:type=trackable_type,polymorphic"`
}
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); err != nil {
panic(err)
}
defer func() {
_ = dropSchema(ctx, db, (*Comment)(nil), (*Article)(nil), (*Post)(nil))
}()
{
article := new(Article)
if err := db.NewSelect().
Model(article).
Relation("Comments").
Where("id = 1").
Scan(ctx); err != nil {
panic(err)
}
spew.Dump(article)
}
{
post := new(Post)
if err := db.NewSelect().
Model(post).
Relation("Comments").
Where("id = 1").
Scan(ctx); err != nil {
panic(err)
}
spew.Dump(post)
}
}
func createSchema(ctx context.Context, db *ogx.DB) error {
// Register models for the fixture.
db.RegisterModel((*Comment)(nil), (*Article)(nil), (*Post)(nil))
// Create tables and load initial data.
fixture := dbfixture.New(db, dbfixture.WithRecreateTables())
if err := fixture.Load(ctx, os.DirFS("."), "fixture.yml"); 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
}