feat: add generic support for QueryResult

Result.go

@@ -73,6 +73,18 @@ func (r *QueryResult) To(result any) error {
 	return r.makeResults(result, r.rows)
 }
 
+func ToSlice[T any](r *QueryResult) ([]T, error) {
+	var result []T
+	err := r.To(&result)
+	return result, err
+}
+
+func ToValue[T any](r *QueryResult) (T, error) {
+	var result T
+	err := r.To(&result)
+	return result, err
+}
+
 func (r *QueryResult) MapResults() []map[string]any {
 	result := make([]map[string]any, 0)
 	err := r.makeResults(&result, r.rows)

generic_test.go

@@ -0,0 +1,47 @@
+package db_test
+
+import (
+	"testing"
+	"apigo.cc/go/db"
+	_ "modernc.org/sqlite"
+)
+
+func TestGenericQuery(t *testing.T) {
+	dbInst := db.GetDB("sqlite://:memory:", nil)
+	if dbInst == nil {
+		t.Fatal("Failed to get DB")
+	}
+
+	dbInst.Exec("CREATE TABLE test_generic (id INTEGER PRIMARY KEY, name TEXT)")
+	dbInst.Exec("INSERT INTO test_generic (name) VALUES (?)", "Alice")
+	dbInst.Exec("INSERT INTO test_generic (name) VALUES (?)", "Bob")
+
+	t.Run("ToSlice", func(t *testing.T) {
+		type Item struct {
+			Id   int
+			Name string
+		}
+		res := dbInst.Query("SELECT id, name FROM test_generic ORDER BY id")
+		items, err := db.ToSlice[Item](res)
+		if err != nil {
+			t.Fatalf("ToSlice failed: %v", err)
+		}
+		if len(items) != 2 {
+			t.Errorf("Expected 2 items, got %d", len(items))
+		}
+		if items[0].Name != "Alice" || items[1].Name != "Bob" {
+			t.Errorf("Incorrect data: %+v", items)
+		}
+	})
+
+	t.Run("ToValue", func(t *testing.T) {
+		res := dbInst.Query("SELECT name FROM test_generic WHERE id = ?", 1)
+		name, err := db.ToValue[string](res)
+		if err != nil {
+			t.Fatalf("ToValue failed: %v", err)
+		}
+		if name != "Alice" {
+			t.Errorf("Expected Alice, got %s", name)
+		}
+	})
+}