GORM provides Context support, you can use it with method WithContext

Single Session Mode

Single session mode usually used when you want to perform a single operation

1. db.WithContext(ctx).Find(&users)

Continuous session mode

Continuous session mode usually used when you want to perform a group of operations, for example:

1. tx := db.WithContext(ctx)
2. tx.First(&user, 1)
3. tx.Model(&user).Update("role", "admin")

Context in Hooks/Callbacks

You could access the Context object from current Statement, for example:

1. func (u *User) BeforeCreate(tx *gorm.DB) (err error) {
2. ctx := tx.Statement.Context
3. // ...
4. return
5. }

Chi Middleware Example

Continuous session mode which might be helpful when handling API requests, for example, you can set up *gorm.DB with Timeout Context in middlewares, and then use the *gorm.DB when processing all requests

Following is a Chi middleware example:

1. func SetDBMiddleware(next http.Handler) http.Handler {
2. return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
3. timeoutContext, _ := context.WithTimeout(context.Background(), time.Second)
4. ctx := context.WithValue(r.Context(), "DB", db.WithContext(timeoutContext))
5. next.ServeHTTP(w, r.WithContext(ctx))
6. })
7. }

9. r := chi.NewRouter()
10. r.Use(SetDBMiddleware)

12. r.Get("/", func(w http.ResponseWriter, r *http.Request) {
13. db, ok := ctx.Value("DB").(*gorm.DB)

15. var users []User
16. db.Find(&users)

18. // lots of db operations
19. })

21. r.Get("/user", func(w http.ResponseWriter, r *http.Request) {
22. db, ok := ctx.Value("DB").(*gorm.DB)

24. var user User
25. db.First(&user)

27. // lots of db operations
28. })

NOTE Set Context with WithContext is goroutine-safe, refer Session for details

Logger

Logger accepts Context too, you can use it for log tracking, refer Logger for details