Datetime docs?

[zachgrayio]

given schema

box.schema.space.create('some_space', {
    format = {
        {name = 'somedate', type = 'datetime'},
        ... 
    }
})

trying to write some data with the go driver gets me:

Tuple field 13 (somedate) type does not match one required by operation: expected datetime, got string

changing the schema to type = 'string' and it seems to just work fine, so I assume either the datetime package isn't functioning as expected, and again there's no docs or full examples. is this expected? am I doing something wrong? can we get some docs created someday?

[oleg-jukovec]

Hello, could you please provide a reproducer with the connector code?

There is an example:

https://pkg.go.dev/github.com/tarantool/go-tarantool@v1.10.0/datetime#example-package

go-tarantool/datetime/example_test.go

Lines 21 to 81 in 64e41c5

	func Example() {
	opts := tarantool.Opts{
	User: "test",
	Pass: "test",
	}
	conn, err := tarantool.Connect("127.0.0.1:3013", opts)
	if err != nil {
	fmt.Printf("Error in connect is %v", err)
	return
	}
	var datetime = "2013-10-28T17:51:56.000000009Z"
	tm, err := time.Parse(time.RFC3339, datetime)
	if err != nil {
	fmt.Printf("Error in time.Parse() is %v", err)
	return
	}
	dt, err := NewDatetime(tm)
	if err != nil {
	fmt.Printf("Unable to create Datetime from %s: %s", tm, err)
	return
	}
	space := "testDatetime_1"
	index := "primary"
	// Replace a tuple with datetime.
	resp, err := conn.Replace(space, []interface{}{dt})
	if err != nil {
	fmt.Printf("Error in replace is %v", err)
	return
	}
	respDt := resp.Data[0].([]interface{})[0].(Datetime)
	fmt.Println("Datetime tuple replace")
	fmt.Printf("Code: %d\n", resp.Code)
	fmt.Printf("Data: %v\n", respDt.ToTime())
	// Select a tuple with datetime.
	var offset uint32 = 0
	var limit uint32 = 1
	resp, err = conn.Select(space, index, offset, limit, tarantool.IterEq, []interface{}{dt})
	if err != nil {
	fmt.Printf("Error in select is %v", err)
	return
	}
	respDt = resp.Data[0].([]interface{})[0].(Datetime)
	fmt.Println("Datetime tuple select")
	fmt.Printf("Code: %d\n", resp.Code)
	fmt.Printf("Data: %v\n", respDt.ToTime())
	// Delete a tuple with datetime.
	resp, err = conn.Delete(space, index, []interface{}{dt})
	if err != nil {
	fmt.Printf("Error in delete is %v", err)
	return
	}
	respDt = resp.Data[0].([]interface{})[0].(Datetime)
	fmt.Println("Datetime tuple delete")
	fmt.Printf("Code: %d\n", resp.Code)
	fmt.Printf("Data: %v\n", respDt.ToTime())
	}

[zachgrayio]

After spending some more time on this probably the issue was somewhere else in the stack, though with a clearer example somewhere I could have ruled it out sooner before coming here.

In particular, you aren't showing an end to end example of saving this into a space (what does the space def look like in the example tests you shared?)

Also lacking is a complete example of a real entity/struct defined actually using the datetime type as a member prop etc so you really need to be motivated to find the answer, not great for newcomers to tarantool which I would assume many users of the Golang drivers will be

[oleg-jukovec]

The space has a just datetime field:

go-tarantool/datetime/config.lua

Line 17 in ab1fb93

local s_1 = box.schema.space.create('testDatetime_1', {

Let's summarize. We need to improve our datetime examples:

1. Add a comment with space.create().
2. Add an example with a tuple as a custom structure type.