Merge pull request #11 from thatguystone/master

Support NULLs in Scan()

sql.go

@@ -13,35 +13,36 @@ import (
 // Currently, database types that map to string and []byte are supported. Please
 // consult database-specific driver documentation for matching types.
 func (uuid *UUID) Scan(src interface{}) error {
-	switch src.(type) {
+	switch src := src.(type) {
+	case nil:
+		return nil
+
 	case string:
 		// if an empty UUID comes from a table, we return a null UUID
-		if src.(string) == "" {
+		if src == "" {
 			return nil
 		}
 
 		// see Parse for required string format
-		u, err := Parse(src.(string))
-
+		u, err := Parse(src)
 		if err != nil {
 			return fmt.Errorf("Scan: %v", err)
 		}
 
 		*uuid = u
-	case []byte:
-		b := src.([]byte)
 
+	case []byte:
 		// if an empty UUID comes from a table, we return a null UUID
-		if len(b) == 0 {
+		if len(src) == 0 {
 			return nil
 		}
 
 		// assumes a simple slice of bytes if 16 bytes
 		// otherwise attempts to parse
-		if len(b) != 16 {
-			return uuid.Scan(string(b))
+		if len(src) != 16 {
+			return uuid.Scan(string(src))
 		}
-		copy((*uuid)[:], b)
+		copy((*uuid)[:], src)
 
 	default:
 		return fmt.Errorf("Scan: unable to scan type %T into UUID", src)

sql_test.go

@@ -90,6 +90,17 @@ func TestScan(t *testing.T) {
 			t.Error("UUID was not nil after scanning empty byte slice")
 		}
 	}
+
+	uuid = UUID{}
+	err = (&uuid).Scan(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, v := range uuid {
+		if v != 0 {
+			t.Error("UUID was not nil after scanning nil")
+		}
+	}
 }
 
 func TestValue(t *testing.T) {