feat(string): added nullable String/Null for sql/json

CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [1.5.1] 
 - !fix(orderby): use BuildOption instead of allowedColumns (#46)
+- feat(string): added nullable String/Null for sql/json (#47)
 
 ## [1.5.0] - 2024-04-30
 ### Changed

bool_test.go

@@ -11,7 +11,7 @@ func TestBool(t *testing.T) {
 	d, err := sql.Open("sqlite3", "file::memory:")
 	require.NoError(t, err)
 
-	_, err = d.Exec("CREATE TABLE `users` (`id` id NOT NULL,`status` BIT(1), PRIMARY KEY (`id`))")
+	_, err = d.Exec("CREATE TABLE `users` (`id` int NOT NULL,`status` BIT(1), PRIMARY KEY (`id`))")
 	require.NoError(t, err)
 
 	result, err := d.Exec("INSERT INTO `users`(`id`, `status`) VALUES(?, ?)", 10, Bool(true))

null.go

@@ -0,0 +1,61 @@
+package sqle
+
+import (
+	"database/sql"
+	"database/sql/driver"
+	"encoding/json"
+)
+
+var nullJsonBytes = []byte("null")
+
+const nullJson = "null"
+
+type Null[T any] struct {
+	sql.Null[T]
+}
+
+func NewNull[T any](v T, valid bool) Null[T] {
+	return Null[T]{Null: sql.Null[T]{V: v, Valid: valid}}
+}
+
+// Scan implements the [sql.Scanner] interface.
+func (t *Null[T]) Scan(value any) error { // skipcq: GO-W1029
+	return t.Null.Scan(value)
+}
+
+// Value implements the [driver.Valuer] interface.
+func (t Null[T]) Value() (driver.Value, error) { // skipcq: GO-W1029
+	return t.Null.Value()
+}
+
+// TValue returns the underlying value of the Null struct.
+func (t *Null[T]) TValue() T { // skipcq: GO-W1029
+	return t.Null.V
+}
+
+// MarshalJSON implements the json.Marshaler interface
+func (t Null[T]) MarshalJSON() ([]byte, error) { // skipcq: GO-W1029
+	if t.Valid {
+		return json.Marshal(t.Null.V)
+	}
+	return nullJsonBytes, nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface
+func (t *Null[T]) UnmarshalJSON(data []byte) error { // skipcq: GO-W1029
+	if len(data) == 0 || string(data) == nullJson {
+		t.Null.Valid = false
+		return nil
+	}
+
+	var v T
+	err := json.Unmarshal(data, &v)
+	if err != nil {
+		return err
+	}
+
+	t.Null.V = v
+	t.Null.Valid = true
+
+	return nil
+}

null_test.go

@@ -0,0 +1,112 @@
+package sqle
+
+import (
+	"database/sql"
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestNullInSQL(t *testing.T) {
+
+	v := float64(10.5)
+	d, err := sql.Open("sqlite3", "file::memory:")
+	require.NoError(t, err)
+
+	_, err = d.Exec("CREATE TABLE `nulls` (`id` int NOT NULL,`value` DECIMAL(10, 2), PRIMARY KEY (`id`))")
+	require.NoError(t, err)
+
+	result, err := d.Exec("INSERT INTO `nulls`(`id`) VALUES(?)", 10)
+	require.NoError(t, err)
+
+	rows, err := result.RowsAffected()
+	require.NoError(t, err)
+	require.Equal(t, int64(1), rows)
+
+	result, err = d.Exec("INSERT INTO `nulls`(`id`, `value`) VALUES(?, ?)", 20, v)
+	require.NoError(t, err)
+
+	rows, err = result.RowsAffected()
+	require.NoError(t, err)
+	require.Equal(t, int64(1), rows)
+
+	var v10 Null[float64]
+	err = d.QueryRow("SELECT `value` FROM `nulls` WHERE id=?", 10).Scan(&v10)
+	require.NoError(t, err)
+
+	require.EqualValues(t, false, v10.Valid)
+
+	var v20 Null[float64]
+	err = d.QueryRow("SELECT `value` FROM `nulls` WHERE id=?", 20).Scan(&v20)
+	require.NoError(t, err)
+
+	require.EqualValues(t, true, v20.Valid)
+	require.EqualValues(t, v, v20.TValue())
+
+	result, err = d.Exec("INSERT INTO `nulls`(`id`,`value`) VALUES(?, ?)", 11, v10)
+	require.NoError(t, err)
+
+	rows, err = result.RowsAffected()
+	require.NoError(t, err)
+	require.Equal(t, int64(1), rows)
+
+	result, err = d.Exec("INSERT INTO `nulls`(`id`, `value`) VALUES(?, ?)", 21, v20)
+	require.NoError(t, err)
+
+	rows, err = result.RowsAffected()
+	require.NoError(t, err)
+	require.Equal(t, int64(1), rows)
+
+	var v11 Null[float64]
+	err = d.QueryRow("SELECT `value` FROM `nulls` WHERE id=?", 11).Scan(&v11)
+	require.NoError(t, err)
+
+	require.EqualValues(t, false, v11.Valid)
+
+	var v21 Null[float64]
+	err = d.QueryRow("SELECT `value` FROM `nulls` WHERE id=?", 21).Scan(&v21)
+	require.NoError(t, err)
+
+	require.EqualValues(t, true, v21.Valid)
+	require.EqualValues(t, v, v21.TValue())
+
+}
+
+func TestNullInJSON(t *testing.T) {
+
+	sysValue := 10.5
+
+	bufSysValue, err := json.Marshal(sysValue)
+	require.NoError(t, err)
+
+	sqleNull := NewNull(sysValue, true)
+
+	bufSqleNull, err := json.Marshal(sqleNull)
+	require.NoError(t, err)
+
+	require.Equal(t, bufSysValue, bufSqleNull)
+
+	var jsSqleValue Null[float64]
+	// Unmarshal sqle.Time from time.Time json bytes
+	err = json.Unmarshal(bufSysValue, &jsSqleValue)
+	require.NoError(t, err)
+
+	require.Equal(t, sysValue, jsSqleValue.TValue())
+	require.Equal(t, true, jsSqleValue.Valid)
+
+	var jsSysValue float64
+	// Unmarshal time.Time from sqle.Time json bytes
+	err = json.Unmarshal(bufSqleNull, &jsSysValue)
+	require.NoError(t, err)
+	require.Equal(t, sysValue, jsSysValue)
+
+	var nullValue Null[float64]
+	err = json.Unmarshal([]byte("null"), &nullValue)
+	require.NoError(t, err)
+	require.Equal(t, false, nullValue.Valid)
+
+	bufNull, err := json.Marshal(nullValue)
+	require.NoError(t, err)
+	require.Equal(t, []byte("null"), bufNull)
+}

string.go

@@ -0,0 +1,56 @@
+package sqle
+
+import (
+	"database/sql/driver"
+	"encoding/json"
+)
+
+type String struct {
+	Null[string]
+}
+
+func NewString(s string) String {
+	return String{Null: NewNull(s, true)}
+}
+
+// Scan implements the [sql.Scanner] interface.
+func (t *String) Scan(value any) error { // skipcq: GO-W1029
+	return t.Null.Scan(value)
+}
+
+// Value implements the [driver.Valuer] interface.
+func (t String) Value() (driver.Value, error) { // skipcq: GO-W1029
+	return t.Null.Value()
+}
+
+// Time returns the underlying time.Time value of the Time struct.
+func (t *String) String() string { // skipcq: GO-W1029
+	return t.TValue()
+}
+
+// MarshalJSON implements the json.Marshaler interface
+func (t String) MarshalJSON() ([]byte, error) { // skipcq: GO-W1029
+	if t.Valid {
+		return json.Marshal(t.TValue())
+	}
+	return nullJsonBytes, nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface
+func (t *String) UnmarshalJSON(data []byte) error { // skipcq: GO-W1029
+	if len(data) == 0 || string(data) == nullJson {
+		t.Null.Valid = false
+		return nil
+	}
+
+	var v string
+	err := json.Unmarshal(data, &v)
+	if err != nil {
+		return err
+	}
+
+	t.Null.V = v
+	t.Null.Valid = true
+
+	return nil
+}

string_test.go

@@ -0,0 +1,112 @@
+package sqle
+
+import (
+	"database/sql"
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestStringInSQL(t *testing.T) {
+
+	v := "has value"
+	d, err := sql.Open("sqlite3", "file::memory:")
+	require.NoError(t, err)
+
+	_, err = d.Exec("CREATE TABLE `strings` (`id` int NOT NULL,`name` varchar(125), PRIMARY KEY (`id`))")
+	require.NoError(t, err)
+
+	result, err := d.Exec("INSERT INTO `strings`(`id`) VALUES(?)", 10)
+	require.NoError(t, err)
+
+	rows, err := result.RowsAffected()
+	require.NoError(t, err)
+	require.Equal(t, int64(1), rows)
+
+	result, err = d.Exec("INSERT INTO `strings`(`id`, `name`) VALUES(?, ?)", 20, v)
+	require.NoError(t, err)
+
+	rows, err = result.RowsAffected()
+	require.NoError(t, err)
+	require.Equal(t, int64(1), rows)
+
+	var v10 String
+	err = d.QueryRow("SELECT `name` FROM `strings` WHERE id=?", 10).Scan(&v10)
+	require.NoError(t, err)
+
+	require.EqualValues(t, false, v10.Valid)
+
+	var v20 String
+	err = d.QueryRow("SELECT `name` FROM `strings` WHERE id=?", 20).Scan(&v20)
+	require.NoError(t, err)
+
+	require.EqualValues(t, true, v20.Valid)
+	require.EqualValues(t, v, v20.String())
+
+	result, err = d.Exec("INSERT INTO `strings`(`id`,`name`) VALUES(?, ?)", 11, v10)
+	require.NoError(t, err)
+
+	rows, err = result.RowsAffected()
+	require.NoError(t, err)
+	require.Equal(t, int64(1), rows)
+
+	result, err = d.Exec("INSERT INTO `strings`(`id`, `name`) VALUES(?, ?)", 21, v20)
+	require.NoError(t, err)
+
+	rows, err = result.RowsAffected()
+	require.NoError(t, err)
+	require.Equal(t, int64(1), rows)
+
+	var v11 String
+	err = d.QueryRow("SELECT `name` FROM `strings` WHERE id=?", 11).Scan(&v11)
+	require.NoError(t, err)
+
+	require.EqualValues(t, false, v11.Valid)
+
+	var v21 String
+	err = d.QueryRow("SELECT `name` FROM `strings` WHERE id=?", 21).Scan(&v21)
+	require.NoError(t, err)
+
+	require.EqualValues(t, true, v21.Valid)
+	require.EqualValues(t, v, v21.String())
+
+}
+
+func TestStringInJSON(t *testing.T) {
+
+	sysString := "has value"
+
+	bufSysString, err := json.Marshal(sysString)
+	require.NoError(t, err)
+
+	sqleString := NewString(sysString)
+
+	bufSqleString, err := json.Marshal(sqleString)
+	require.NoError(t, err)
+
+	require.Equal(t, bufSysString, bufSqleString)
+
+	var jsSqleString String
+	// Unmarshal sqle.Time from time.Time json bytes
+	err = json.Unmarshal(bufSysString, &jsSqleString)
+	require.NoError(t, err)
+
+	require.Equal(t, sysString, jsSqleString.String())
+	require.Equal(t, true, jsSqleString.Valid)
+
+	var jsSysString string
+	// Unmarshal time.Time from sqle.Time json bytes
+	err = json.Unmarshal(bufSqleString, &jsSysString)
+	require.NoError(t, err)
+	require.Equal(t, sysString, jsSysString)
+
+	var nullString String
+	err = json.Unmarshal([]byte("null"), &nullString)
+	require.NoError(t, err)
+	require.Equal(t, false, nullString.Valid)
+
+	bufNull, err := json.Marshal(nullString)
+	require.NoError(t, err)
+	require.Equal(t, []byte("null"), bufNull)
+}

time.go

@@ -7,10 +7,6 @@ import (
 	"time"
 )
 
-var nullTimeJsonBytes = []byte("null")
-
-const nullTimeJson = "null"
-
 // Time represents a nullable time value.
 type Time struct {
 	sql.NullTime
@@ -41,12 +37,12 @@ func (t Time) MarshalJSON() ([]byte, error) { // skipcq: GO-W1029
 	if t.Valid {
 		return json.Marshal(t.NullTime.Time)
 	}
-	return nullTimeJsonBytes, nil
+	return nullJsonBytes, nil
 }
 
 // UnmarshalJSON implements the json.Unmarshaler interface
 func (t *Time) UnmarshalJSON(data []byte) error { // skipcq: GO-W1029
-	if len(data) == 0 || string(data) == nullTimeJson {
+	if len(data) == 0 || string(data) == nullJson {
 		t.NullTime.Time = time.Time{}
 		t.NullTime.Valid = false
 		return nil