Golang Conn.QueryRow方法代码示例

func execQuery64(conn *pgx.Conn, stmt string, arguments ...interface{}) int64 {
	var err error
	var result int64
	err = conn.QueryRow(stmt, arguments...).Scan(&result)
	checkErr(err)
	return result
}

func waitRow(c *C, conn *pgx.Conn, n int) {
	var res int64
	err := queryAttempts.Run(func() error {
		return conn.QueryRow("SELECT id FROM test WHERE id = $1", n).Scan(&res)
	})
	c.Assert(err, IsNil)
}

func testJsonInt16ArrayFailureDueToOverflow(t *testing.T, conn *pgx.Conn, typename string) {
	input := []int{1, 2, 234432}
	var output []int16
	err := conn.QueryRow("select $1::"+typename, input).Scan(&output)
	if err == nil || err.Error() != "can't scan into dest[0]: json: cannot unmarshal number 234432 into Go value of type int16" {
		t.Errorf("%s: Expected *json.UnmarkalTypeError, but got %v", typename, err)
	}
}

func testJsonInt16ArrayFailureDueToOverflow(t *testing.T, conn *pgx.Conn, typename string) {
	input := []int{1, 2, 234432}
	var output []int16
	err := conn.QueryRow("select $1::"+typename, input).Scan(&output)
	if _, ok := err.(*json.UnmarshalTypeError); !ok {
		t.Errorf("%s: Expected *json.UnmarkalTypeError, but got %v", typename, err)
	}
}

func benchmarkSelectWithLog(b *testing.B, conn *pgx.Conn) {
	_, err := conn.Prepare("test", "select 1::int4, 'johnsmith', '[email protected]', 'John Smith', 'male', '1970-01-01'::date, '2015-01-01 00:00:00'::timestamptz")
	if err != nil {
		b.Fatal(err)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		var record struct {
			id            int32
			userName      string
			email         string
			name          string
			sex           string
			birthDate     time.Time
			lastLoginTime time.Time
		}

		err = conn.QueryRow("test").Scan(
			&record.id,
			&record.userName,
			&record.email,
			&record.name,
			&record.sex,
			&record.birthDate,
			&record.lastLoginTime,
		)
		if err != nil {
			b.Fatal(err)
		}

		// These checks both ensure that the correct data was returned
		// and provide a benchmark of accessing the returned values.
		if record.id != 1 {
			b.Fatalf("bad value for id: %v", record.id)
		}
		if record.userName != "johnsmith" {
			b.Fatalf("bad value for userName: %v", record.userName)
		}
		if record.email != "[email protected]" {
			b.Fatalf("bad value for email: %v", record.email)
		}
		if record.name != "John Smith" {
			b.Fatalf("bad value for name: %v", record.name)
		}
		if record.sex != "male" {
			b.Fatalf("bad value for sex: %v", record.sex)
		}
		if record.birthDate != time.Date(1970, 1, 1, 0, 0, 0, 0, time.Local) {
			b.Fatalf("bad value for birthDate: %v", record.birthDate)
		}
		if record.lastLoginTime != time.Date(2015, 1, 1, 0, 0, 0, 0, time.Local) {
			b.Fatalf("bad value for lastLoginTime: %v", record.lastLoginTime)
		}
	}
}

func testJsonInt64Array(t *testing.T, conn *pgx.Conn, typename string) {
	input := []int64{1, 2, 234432}
	var output []int64
	err := conn.QueryRow("select $1::"+typename, input).Scan(&output)
	if err != nil {
		t.Errorf("%s: QueryRow Scan failed: %v", typename, err)
	}

	if !reflect.DeepEqual(input, output) {
		t.Errorf("%s: Did not transcode []int64 successfully: %v is not %v", typename, input, output)
	}
}

func testJsonStringArray(t *testing.T, conn *pgx.Conn, typename string) {
	input := []string{"foo", "bar", "baz"}
	var output []string
	err := conn.QueryRow("select $1::"+typename, input).Scan(&output)
	if err != nil {
		t.Errorf("%s: QueryRow Scan failed: %v", typename, err)
	}

	if !reflect.DeepEqual(input, output) {
		t.Errorf("%s: Did not transcode []string successfully: %v is not %v", typename, input, output)
	}
}

func waitReadWrite(c *C, conn *pgx.Conn) {
	var readOnly string
	err := queryAttempts.Run(func() error {
		if err := conn.QueryRow("SHOW default_transaction_read_only").Scan(&readOnly); err != nil {
			return err
		}
		if readOnly == "off" {
			return nil
		}
		return fmt.Errorf("transaction readonly is %q", readOnly)
	})
	c.Assert(err, IsNil)
}

func testJsonSingleLevelStringMap(t *testing.T, conn *pgx.Conn, typename string) {
	input := map[string]string{"key": "value"}
	var output map[string]string
	err := conn.QueryRow("select $1::"+typename, input).Scan(&output)
	if err != nil {
		t.Errorf("%s: QueryRow Scan failed: %v", typename, err)
		return
	}

	if !reflect.DeepEqual(input, output) {
		t.Errorf("%s: Did not transcode map[string]string successfully: %v is not %v", typename, input, output)
		return
	}
}

func waitRecovered(c *C, conn *pgx.Conn) {
	var recovery bool
	err := queryAttempts.Run(func() error {
		err := conn.QueryRow("SELECT pg_is_in_recovery()").Scan(&recovery)
		if err != nil {
			return err
		}
		if recovery {
			return fmt.Errorf("in recovery")
		}
		return nil
	})
	c.Assert(err, IsNil)
}

func testJsonNestedMap(t *testing.T, conn *pgx.Conn, typename string) {
	input := map[string]interface{}{
		"name":      "Uncanny",
		"stats":     map[string]interface{}{"hp": float64(107), "maxhp": float64(150)},
		"inventory": []interface{}{"phone", "key"},
	}
	var output map[string]interface{}
	err := conn.QueryRow("select $1::"+typename, input).Scan(&output)
	if err != nil {
		t.Errorf("%s: QueryRow Scan failed: %v", typename, err)
		return
	}

	if !reflect.DeepEqual(input, output) {
		t.Errorf("%s: Did not transcode map[string]interface{} successfully: %v is not %v", typename, input, output)
		return
	}
}

func testJsonStruct(t *testing.T, conn *pgx.Conn, typename string) {
	type person struct {
		Name string `json:"name"`
		Age  int    `json:"age"`
	}

	input := person{
		Name: "John",
		Age:  42,
	}

	var output person

	err := conn.QueryRow("select $1::"+typename, input).Scan(&output)
	if err != nil {
		t.Errorf("%s: QueryRow Scan failed: %v", typename, err)
	}

	if !reflect.DeepEqual(input, output) {
		t.Errorf("%s: Did not transcode struct successfully: %v is not %v", typename, input, output)
	}
}

func assertRecovery(c *C, conn *pgx.Conn) {
	var recovery bool
	err := conn.QueryRow("SELECT pg_is_in_recovery()").Scan(&recovery)
	c.Assert(err, IsNil)
	c.Assert(recovery, Equals, true)
}

func assertDownstream(c *C, conn *pgx.Conn, n int) {
	var res string
	err := conn.QueryRow("SELECT client_addr FROM pg_stat_replication WHERE application_name = $1", fmt.Sprintf("node%d", n)).Scan(&res)
	c.Assert(err, IsNil)
}