修改部分转换问题

null.go

@@ -0,0 +1,250 @@
+package aorm
+
+import (
+	"bytes"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math"
+	"reflect"
+	"strconv"
+	"time"
+)
+
+// Int 整数
+type Int struct {
+	sql.NullInt64
+}
+
+// IntFrom 创建整数
+func IntFrom(i int64) Int {
+	return Int{
+		NullInt64: sql.NullInt64{
+			Int64: i,
+			Valid: true,
+		},
+	}
+}
+
+// String 字符串
+type String struct {
+	sql.NullString
+}
+
+// StringFrom 创建字符串
+func StringFrom(s string) String {
+	return String{
+		NullString: sql.NullString{
+			String: s,
+			Valid:  true,
+		},
+	}
+}
+
+// Float 浮点数
+type Float struct {
+	sql.NullFloat64
+}
+
+// FloatFrom 创建浮点数
+func FloatFrom(f float64) Float {
+	return Float{
+		NullFloat64: sql.NullFloat64{
+			Float64: f,
+			Valid:   true,
+		},
+	}
+}
+
+// Bool 布尔值
+type Bool struct {
+	sql.NullBool
+}
+
+// BoolFrom 创建布尔值
+func BoolFrom(b bool) Bool {
+	return Bool{
+		NullBool: sql.NullBool{
+			Bool:  b,
+			Valid: true,
+		},
+	}
+}
+
+// Time 时间
+type Time struct {
+	sql.NullTime
+}
+
+// TimeFrom 创建时间
+func TimeFrom(t time.Time) Time {
+	return Time{
+		NullTime: sql.NullTime{
+			Time:  t,
+			Valid: true,
+		},
+	}
+}
+
+var nullBytes = []byte("null")
+
+// UnmarshalJSON 反序列化浮点数
+func (f *Float) UnmarshalJSON(data []byte) error {
+	if bytes.Equal(data, nullBytes) {
+		f.Valid = false
+		return nil
+	}
+
+	if err := json.Unmarshal(data, &f.Float64); err != nil {
+		var typeError *json.UnmarshalTypeError
+		if errors.As(err, &typeError) {
+			// special case: accept string input
+			if typeError.Value != "string" {
+				return fmt.Errorf("null: JSON input is invalid type (need float or string): %w", err)
+			}
+			var str string
+			if err := json.Unmarshal(data, &str); err != nil {
+				return fmt.Errorf("null: couldn't unmarshal number string: %w", err)
+			}
+			n, err := strconv.ParseFloat(str, 64)
+			if err != nil {
+				return fmt.Errorf("null: couldn't convert string to float: %w", err)
+			}
+			f.Float64 = n
+			f.Valid = true
+			return nil
+		}
+		return fmt.Errorf("null: couldn't unmarshal JSON: %w", err)
+	}
+
+	f.Valid = true
+	return nil
+}
+
+// MarshalJSON 序列化浮点数
+func (f Float) MarshalJSON() ([]byte, error) {
+	if !f.Valid {
+		return []byte("null"), nil
+	}
+	if math.IsInf(f.Float64, 0) || math.IsNaN(f.Float64) {
+		return nil, &json.UnsupportedValueError{
+			Value: reflect.ValueOf(f.Float64),
+			Str:   strconv.FormatFloat(f.Float64, 'g', -1, 64),
+		}
+	}
+	return []byte(strconv.FormatFloat(f.Float64, 'f', -1, 64)), nil
+}
+
+// UnmarshalJSON 反序列化布尔值
+func (b *Bool) UnmarshalJSON(data []byte) error {
+	if bytes.Equal(data, nullBytes) {
+		b.Valid = false
+		return nil
+	}
+
+	if err := json.Unmarshal(data, &b.Bool); err != nil {
+		return fmt.Errorf("null: couldn't unmarshal JSON: %w", err)
+	}
+
+	b.Valid = true
+	return nil
+}
+
+// MarshalJSON 序列化布尔值
+func (b Bool) MarshalJSON() ([]byte, error) {
+	if !b.Valid {
+		return []byte("null"), nil
+	}
+	if !b.Bool {
+		return []byte("false"), nil
+	}
+	return []byte("true"), nil
+}
+
+// UnmarshalJSON 反序列化时间
+func (t *Time) UnmarshalJSON(data []byte) error {
+	if bytes.Equal(data, nullBytes) {
+		t.Valid = false
+		return nil
+	}
+
+	if err := json.Unmarshal(data, &t.Time); err != nil {
+		return fmt.Errorf("null: couldn't unmarshal JSON: %w", err)
+	}
+
+	t.Valid = true
+	return nil
+}
+
+// MarshalJSON 序列化时间
+func (t Time) MarshalJSON() ([]byte, error) {
+	if !t.Valid {
+		return []byte("null"), nil
+	}
+	return t.Time.MarshalJSON()
+}
+
+// UnmarshalJSON 反序列化整数
+func (i *Int) UnmarshalJSON(data []byte) error {
+	if bytes.Equal(data, nullBytes) {
+		i.Valid = false
+		return nil
+	}
+
+	if err := json.Unmarshal(data, &i.Int64); err != nil {
+		var typeError *json.UnmarshalTypeError
+		if errors.As(err, &typeError) {
+			// special case: accept string input
+			if typeError.Value != "string" {
+				return fmt.Errorf("null: JSON input is invalid type (need int or string): %w", err)
+			}
+			var str string
+			if err := json.Unmarshal(data, &str); err != nil {
+				return fmt.Errorf("null: couldn't unmarshal number string: %w", err)
+			}
+			n, err := strconv.ParseInt(str, 10, 64)
+			if err != nil {
+				return fmt.Errorf("null: couldn't convert string to int: %w", err)
+			}
+			i.Int64 = n
+			i.Valid = true
+			return nil
+		}
+		return fmt.Errorf("null: couldn't unmarshal JSON: %w", err)
+	}
+
+	i.Valid = true
+	return nil
+}
+
+// MarshalJSON 序列化整数
+func (i Int) MarshalJSON() ([]byte, error) {
+	if !i.Valid {
+		return []byte("null"), nil
+	}
+	return []byte(strconv.FormatInt(i.Int64, 10)), nil
+}
+
+// UnmarshalJSON 反序列化字符串
+func (s *String) UnmarshalJSON(data []byte) error {
+	if bytes.Equal(data, nullBytes) {
+		s.Valid = false
+		return nil
+	}
+
+	if err := json.Unmarshal(data, &s.String); err != nil {
+		return fmt.Errorf("null: couldn't unmarshal JSON: %w", err)
+	}
+
+	s.Valid = true
+	return nil
+}
+
+// MarshalJSON 序列化字符串
+func (s String) MarshalJSON() ([]byte, error) {
+	if !s.Valid {
+		return []byte("null"), nil
+	}
+	return json.Marshal(s.String)
+}