More work to support nullable foreign keys

Adds nullable int/uint types

backend/internal/types/db_nullable_int.go

@@ -0,0 +1,63 @@
+package types
+
+import (
+	"database/sql/driver"
+	"encoding/json"
+	"strconv"
+)
+
+// NullableDBInt works with database values that can be null or an integer value
+type NullableDBInt struct {
+	Int int
+}
+
+// Value encodes the type ready for the database
+func (d NullableDBInt) Value() (driver.Value, error) {
+	if d.Int == 0 {
+		return nil, nil
+	}
+	// According to current database/sql docs, the sql has four builtin functions that
+	// returns driver.Value, and the underlying types are `int64`, `float64`, `string` and `bool`
+	return driver.Value(int64(d.Int)), nil
+}
+
+// Scan takes data from the database and modifies it for Go Types
+func (d *NullableDBInt) Scan(src interface{}) error {
+	var i int
+	switch v := src.(type) {
+	case int:
+		i = v
+	case int64:
+		i = int(v)
+	case float32:
+		i = int(v)
+	case float64:
+		i = int(v)
+	case string:
+		i, _ = strconv.Atoi(v)
+	}
+	d.Int = i
+	return nil
+}
+
+// UnmarshalJSON will unmarshal both database and post given values
+func (d *NullableDBInt) UnmarshalJSON(data []byte) error {
+	// total_deploy_time: 10,
+	// total_deploy_time: null,
+
+	var i int
+	if err := json.Unmarshal(data, &i); err != nil {
+		i = 0
+		return nil
+	}
+	d.Int = i
+	return nil
+}
+
+// MarshalJSON will marshal for output in api responses
+func (d NullableDBInt) MarshalJSON() ([]byte, error) {
+	if d.Int == 0 {
+		return json.Marshal(nil)
+	}
+	return json.Marshal(d.Int)
+}

backend/internal/types/db_nullable_uint.go

@@ -0,0 +1,64 @@
+package types
+
+import (
+	"database/sql/driver"
+	"encoding/json"
+	"strconv"
+)
+
+// NullableDBUint works with database values that can be null or an integer value
+type NullableDBUint struct {
+	Uint uint
+}
+
+// Value encodes the type ready for the database
+func (d NullableDBUint) Value() (driver.Value, error) {
+	if d.Uint == 0 {
+		return nil, nil
+	}
+	// According to current database/sql docs, the sql has four builtin functions that
+	// returns driver.Value, and the underlying types are `int64`, `float64`, `string` and `bool`
+	return driver.Value(int64(d.Uint)), nil
+}
+
+// Scan takes data from the database and modifies it for Go Types
+func (d *NullableDBUint) Scan(src interface{}) error {
+	var i uint
+	switch v := src.(type) {
+	case int:
+		i = uint(v)
+	case int64:
+		i = uint(v)
+	case float32:
+		i = uint(v)
+	case float64:
+		i = uint(v)
+	case string:
+		a, _ := strconv.Atoi(v)
+		i = uint(a)
+	}
+	d.Uint = i
+	return nil
+}
+
+// UnmarshalJSON will unmarshal both database and post given values
+func (d *NullableDBUint) UnmarshalJSON(data []byte) error {
+	// total_deploy_time: 10,
+	// total_deploy_time: null,
+
+	var i uint
+	if err := json.Unmarshal(data, &i); err != nil {
+		i = 0
+		return nil
+	}
+	d.Uint = i
+	return nil
+}
+
+// MarshalJSON will marshal for output in api responses
+func (d NullableDBUint) MarshalJSON() ([]byte, error) {
+	if d.Uint == 0 {
+		return json.Marshal(nil)
+	}
+	return json.Marshal(d.Uint)
+}

backend/internal/types/nullable_db_date.go

@@ -17,6 +17,8 @@ func (d NullableDBDate) Value() (driver.Value, error) {
 	if d.Time == nil {
 		return nil, nil
 	}
+	// According to current database/sql docs, the sql has four builtin functions that
+	// returns driver.Value, and the underlying types are `int64`, `float64`, `string` and `bool`
 	return driver.Value(d.Time.Unix()), nil
 }