Fix Insert issue for default postgres type template Insert operation

[mccolljr]

As far as I can tell, the .Scan here will always fail without the RETURNING clause in the SQL (tried with a couple different drivers, lib/pq and pgx. Rather than add RETURNING when the primary key is set manually, I opted to just use Exec rather than QueryRow.

[kenshaw]

@mccolljr I appreciate the work here -- can you share a small table definition and version of PostgreSQL you were using? There's a good chance that the way xo needs to pull type / sequence information from PostgreSQL has changed and is the real issue of the problem. Before I merge this, I'd like to verify it from my end. Thanks!

[mccolljr]

@kenshaw sorry for the delay, here's a small repro:

# postgres 9.6
CREATE TABLE "team" (
  "id" UUID NOT NULL PRIMARY KEY,
  "name" VARCHAR(100) NOT NULL
)

If you generate this, the Insert method will successfully create a record, but will return sql.ErrNoRows due to the call to Scan.

[mccolljr]

A further example (will have to replace with your own schema)

func TestXOIssue(t *testing.T) {
	db, err := sql.Open("postgres", "postgres://(user):(password)@127.0.0.1:5432/postgres?sslmode=disable")
	if err != nil {
		log.Fatalln(err)
	}
	if err := db.Ping(); err != nil {
		log.Fatalln(err)
	}

	team := models.Team{
		ID:   uuid.NewV4(),
		Name: "test",
	}

        t.Logf("Inserting team: %v", team)

	if err := team.Insert(db); err != nil {
		t.Logf("Insert returned error: %s", err)
	}

	if found, err := models.TeamByID(db, team.ID); err != nil {
		t.Logf("TeamByID returned error: %s", err)
	} else {
		t.Logf("TeamByID found team: %v", found)
	}
}

go test -v output for this test:

=== RUN   TestXOIssue
    TestXOIssue: xo_test.go:26: Inserting team: {e830900b-f04f-4e65-869e-cec27a8de2a6 test false false}
    TestXOIssue: xo_test.go:29: Insert returned error: sql: no rows in result set
    TestXOIssue: xo_test.go:35: TeamByID found team: &{e830900b-f04f-4e65-869e-cec27a8de2a6 test true false}
--- PASS: TestXOIssue (0.01s)

[mccolljr]

The generated code (using default templates)

// Insert inserts the Team to the database.
func (t *Team) Insert(db XODB) error {
	var err error

	// if already exist, bail
	if t._exists {
		return errors.New("insert failed: already exists")
	}

	// sql insert query, primary key must be provided
	const sqlstr = `INSERT INTO "public"."teams" (` +
		`"id", "name"` +
		`) VALUES (` +
		`$1, $2` +
		`)`

	// run query
	XOLog(sqlstr, t.ID, t.Name)
	err = db.QueryRow(sqlstr, t.ID, t.Name).Scan(&t.ID)
	if err != nil {
		return err
	}

	// set existence
	t._exists = true

	return nil
}

[turnkey-commerce]

It looks like this tests fine, but also had to run the tpl.sh to update the go-bindata code with the change.

[mccolljr]

@turnkey-commerce thanks for making the fix. I put this PR in from the GitHub web UI, and had forgotten that codegen needed to be run. 👍