Add nullable civil types (NullDate, NullDateTime, NullTime)

Co-authored-by: shueybubbles <[email protected]>

Author: Copilot

civil_null.go

@@ -0,0 +1,214 @@
+package mssql
+
+import (
+	"database/sql/driver"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/golang-sql/civil"
+)
+
+// NullDate represents a civil.Date that may be null.
+// NullDate implements the Scanner interface so it can be used as a scan destination,
+// similar to sql.NullString.
+type NullDate struct {
+	Date  civil.Date
+	Valid bool // Valid is true if Date is not NULL
+}
+
+// Scan implements the Scanner interface.
+func (n *NullDate) Scan(value interface{}) error {
+	if value == nil {
+		n.Date, n.Valid = civil.Date{}, false
+		return nil
+	}
+	n.Valid = true
+	switch v := value.(type) {
+	case time.Time:
+		n.Date = civil.DateOf(v)
+		return nil
+	default:
+		n.Valid = false
+		return fmt.Errorf("cannot scan %T into NullDate", value)
+	}
+}
+
+// Value implements the driver Valuer interface.
+func (n NullDate) Value() (driver.Value, error) {
+	if !n.Valid {
+		return nil, nil
+	}
+	return n.Date, nil
+}
+
+// String returns the string representation of the date or "NULL".
+func (n NullDate) String() string {
+	if !n.Valid {
+		return "NULL"
+	}
+	return n.Date.String()
+}
+
+// MarshalText implements the encoding.TextMarshaler interface.
+func (n NullDate) MarshalText() ([]byte, error) {
+	if !n.Valid {
+		return []byte("null"), nil
+	}
+	return n.Date.MarshalText()
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (n *NullDate) UnmarshalJSON(b []byte) error {
+	if string(b) == "null" {
+		n.Date, n.Valid = civil.Date{}, false
+		return nil
+	}
+	err := json.Unmarshal(b, &n.Date)
+	n.Valid = err == nil
+	return err
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (n NullDate) MarshalJSON() ([]byte, error) {
+	if !n.Valid {
+		return []byte("null"), nil
+	}
+	return json.Marshal(n.Date)
+}
+
+// NullDateTime represents a civil.DateTime that may be null.
+// NullDateTime implements the Scanner interface so it can be used as a scan destination,
+// similar to sql.NullString.
+type NullDateTime struct {
+	DateTime civil.DateTime
+	Valid    bool // Valid is true if DateTime is not NULL
+}
+
+// Scan implements the Scanner interface.
+func (n *NullDateTime) Scan(value interface{}) error {
+	if value == nil {
+		n.DateTime, n.Valid = civil.DateTime{}, false
+		return nil
+	}
+	n.Valid = true
+	switch v := value.(type) {
+	case time.Time:
+		n.DateTime = civil.DateTimeOf(v)
+		return nil
+	default:
+		n.Valid = false
+		return fmt.Errorf("cannot scan %T into NullDateTime", value)
+	}
+}
+
+// Value implements the driver Valuer interface.
+func (n NullDateTime) Value() (driver.Value, error) {
+	if !n.Valid {
+		return nil, nil
+	}
+	return n.DateTime, nil
+}
+
+// String returns the string representation of the datetime or "NULL".
+func (n NullDateTime) String() string {
+	if !n.Valid {
+		return "NULL"
+	}
+	return n.DateTime.String()
+}
+
+// MarshalText implements the encoding.TextMarshaler interface.
+func (n NullDateTime) MarshalText() ([]byte, error) {
+	if !n.Valid {
+		return []byte("null"), nil
+	}
+	return n.DateTime.MarshalText()
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (n *NullDateTime) UnmarshalJSON(b []byte) error {
+	if string(b) == "null" {
+		n.DateTime, n.Valid = civil.DateTime{}, false
+		return nil
+	}
+	err := json.Unmarshal(b, &n.DateTime)
+	n.Valid = err == nil
+	return err
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (n NullDateTime) MarshalJSON() ([]byte, error) {
+	if !n.Valid {
+		return []byte("null"), nil
+	}
+	return json.Marshal(n.DateTime)
+}
+
+// NullTime represents a civil.Time that may be null.
+// NullTime implements the Scanner interface so it can be used as a scan destination,
+// similar to sql.NullString.
+type NullTime struct {
+	Time  civil.Time
+	Valid bool // Valid is true if Time is not NULL
+}
+
+// Scan implements the Scanner interface.
+func (n *NullTime) Scan(value interface{}) error {
+	if value == nil {
+		n.Time, n.Valid = civil.Time{}, false
+		return nil
+	}
+	n.Valid = true
+	switch v := value.(type) {
+	case time.Time:
+		n.Time = civil.TimeOf(v)
+		return nil
+	default:
+		n.Valid = false
+		return fmt.Errorf("cannot scan %T into NullTime", value)
+	}
+}
+
+// Value implements the driver Valuer interface.
+func (n NullTime) Value() (driver.Value, error) {
+	if !n.Valid {
+		return nil, nil
+	}
+	return n.Time, nil
+}
+
+// String returns the string representation of the time or "NULL".
+func (n NullTime) String() string {
+	if !n.Valid {
+		return "NULL"
+	}
+	return n.Time.String()
+}
+
+// MarshalText implements the encoding.TextMarshaler interface.
+func (n NullTime) MarshalText() ([]byte, error) {
+	if !n.Valid {
+		return []byte("null"), nil
+	}
+	return n.Time.MarshalText()
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (n *NullTime) UnmarshalJSON(b []byte) error {
+	if string(b) == "null" {
+		n.Time, n.Valid = civil.Time{}, false
+		return nil
+	}
+	err := json.Unmarshal(b, &n.Time)
+	n.Valid = err == nil
+	return err
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (n NullTime) MarshalJSON() ([]byte, error) {
+	if !n.Valid {
+		return []byte("null"), nil
+	}
+	return json.Marshal(n.Time)
+}