How implement struct for use in crud insert request?

[siller174]

How implement struct for put in crud request?

Example with map

	insert := crud.MakeInsertObjectRequest("user").
			Object(
				crud.MapObject(map[string]interface{}{
					"id":         userUUID,
					"created_at": time.Now().Unix(),
					"buc1ket_id": nil,
				})).
			Context(ctx)

But i want implement myself Object.

I should use this interface:

type encoder = msgpack.Encoder
type decoder = msgpack.Decoder

// Object is an interface to describe object for CRUD methods.
type Object interface {
	EncodeMsgpack(enc *encoder)
}

with private field encoder.

My struct

type Customer struct {
	ID        string `msgpack:"'id'"`
	CreatedAt string `msgpack:"'created_at'"`
	BucketID  *int64 `msgpack:"'bucket_id'"`
}

func (c *Customer) EncodeMsgpack(enc *msgpack.Encoder) {
	enc.Encode(&c)
}

What am i doing wrong?

[oleg-jukovec]

Hello. Could you please provide more information about the issue you're facing? What specific error message or problem are you encountering?

You could insert a tuple with InsertRequest:

type exampleInsertTuple struct {
	_msgpack struct{} `msgpack:",asArray"` //nolint: structcheck,unused
	ID        uint
	BucketID  *uint	
	Name      string
}

func ExampleInsertRequest() {
	conn := exampleConnect()
	tup := exampleInsertTuple{
		ID:       2024,
		BucketID: nil,
		Name:     "foo",
	}
	req := crud.MakeInsertRequest(exampleSpace).Tuple(tup)

	ret := crud.Result{}
	if err := conn.Do(req).GetTyped(&ret); err != nil {
		fmt.Printf("Failed to execute request: %s", err)
	} else {
		fmt.Println(ret.Metadata)
		fmt.Println(ret.Rows)
	}
	// Output:
	// [{id unsigned false} {bucket_id unsigned true} {name string false}]
	// [[2024 263 foo]]
}

or an object with InsertObjectRequest:

type exampleInsertObject struct {
	ID        uint   `msgpack:"'id'"`
	BucketID  *uint  `msgpack:"'bucket_id'"`	
	Name      string `msgpack:"'name'"`
}

func (e *exampleInsertObject) EncodeMsgpack(enc *msgpack.Encoder) {
	enc.Encode(e)
}

func ExampleInsertObjectRequest() {
	conn := exampleConnect()
	obj := exampleInsertObject{
		ID:       2022,
		BucketID: nil,
		Name:     "foo",
	}
	req := crud.MakeInsertObjectRequest(exampleSpace).Object(&obj)

	ret := crud.Result{}
	if err := conn.Do(req).GetTyped(&ret); err != nil {
		fmt.Printf("Failed to execute request: %s", err)
	} else {
		fmt.Println(ret.Metadata)
		fmt.Println(ret.Rows)
	}
	// Output:
	// [{id unsigned false} {bucket_id unsigned true} {name string false}]
	// [[2022 263 foo]]
}

The examples are works with out test space format:

https://github.com/tarantool/go-tarantool/blob/b30e2b69c9fca74953178afe9a80c38530d85aff/crud/testdata/config.lua#L45-L47

You could add the code into crud/example_test.go and run an example with a command:

$ cd crud && go test -v . -run ExampleInsertRequest

or

$ cd crud && go test -v . -run ExampleInsertObjectRequest

TODO: add an example with *ObjectRequest to crud/example_test.go.

[siller174]

Yes, thank you. Main problem in crud is examples, it's really hard to integrate. Could you also write example for crud.MakeUpsertManyRequest?

[DifferentialOrange]

Btw, if you mean "put" as "write a record disregarding whether a record with such primary key exist or not", it's Replace operations you are looking for. Insert operations throw error when you're trying to overwrite an existing record.

[siller174]

@oleg-jukovec. One more question with crud.

How implement pagination select request?

For example in Lua

s:select({0},{iterator='GT',offset=1,limit=2})

In Options i found this

	// First describes the maximum count of the objects to return.
	First OptInt
	// After is a tuple after which objects should be selected.
	After OptTuple
	// BatchSize is a number of tuples to process per one request to storage.
	BatchSize OptUint

But didn't find offset parameter.

[siller174]

@DifferentialOrange thank you!

[oleg-jukovec]

@oleg-jukovec. One more question with crud. But didn't find offset parameter.

crud's select does not have the offset parameter:

https://github.com/tarantool/crud/#select

You need to use After + First as it is described for crud:

https://github.com/tarantool/crud/blob/master/doc/select.md#pagination

[siller174]

Okay :( So I should make 2 requests: First for get object for After, Second for make select with pagination?

[oleg-jukovec]

There is no difference between original crud. A pagination logic wtih crud looks like this:

res, err = crud.select('developers', nil, { first = 5 })
for i = 0; i < 10; i++ then
    res, err = crud.select('developers', nil, { after = res.rows[5], first = 5 })
end

go-tarantool just provides wrappers around Lua's requests without additional logic.

[siller174]

Thank you

[siller174]

I'm very sorry for so many questions.

But I have no idea, what I do wrong

const space = "user"

type User struct {
	_msgpack struct{} `msgpack:",asArray"` //nolint: structcheck,unused

	ID        string `msgpack:"id"`
	CreatedAt string `msgpack:"created_at"`
	BucketID  *uint  `msgpack:"'bucket_id'"`
}

func (e *User) EncodeMsgpack(enc *msgpack.Encoder) {
	enc.Encode(e)
}

func main() {
	var (
		user = "admin"
		pass = "secret-cluster-cookie"
		dsn  = "localhost:3301"

		ctx = context.Background()

		offset = 2
		limit  = 2
	)

	connection, err := tarantool.New(user, pass, dsn)
	if err != nil {
		panic(err)
	}

	if offset == 0 {
		offset = limit
	}

	var (
		req = crud.MakeSelectRequest(space).
			Context(ctx).
			Opts(crud.SelectOpts{
				First: crud.MakeOptInt(limit),
			})
		ret = crud.MakeResult(reflect.TypeOf(User{}))
	)

	if err := connection.Do(req).GetTyped(&ret); err != nil {
		panic(err)
	}

	users := ret.Rows.([]User)
	if len(users) == 0 {
		panic("len(users) == 0")
	}

	u := users[offset-1]

	req = crud.MakeSelectRequest(space).
		Context(ctx).
		Opts(crud.SelectOpts{
			First: crud.MakeOptInt(limit),
			After: crud.MakeOptTuple(&u),
		})

	if err := connection.Do(req).GetTyped(&ret); err != nil {
		panic(err)
	}

	fmt.Println(ret.Metadata)
	fmt.Println(ret.Rows.([]User))
	fmt.Println("len: ", len(ret.Rows.([]User)))
}

[oleg-jukovec]

Could you please provide more information about the issue you're facing? What specific error message or problem are you encountering?

[siller174]

I just want to implement pagination logic

[oleg-jukovec]

I just want to implement pagination logic

What specific error message are you encountering?

Is the fix relevant for you problem?

https://github.com/tarantool/go-tarantool/pull/323

[siller174]

@oleg-jukovec yes, i just checked it with fix. Thank you.