storage: Query method and QueryData function

storage/sql/sql.go

@@ -10,6 +10,8 @@ type Cfg struct {
 	Driver, Connstr string
 }
 
+type rowsProc = func(*sql.Rows) error
+
 type Storage struct {
 	*sql.DB
 }
@@ -23,8 +25,42 @@ func Open(cfg *Cfg) *Storage {
 	return &Storage{db}
 }
 
+func QueryData[T any](db *Storage, q string, args ...interface{}) []T {
+	var data []T
+	proc := func(r *sql.Rows) error {
+		var rec T
+		err := r.Scan(&rec)
+		data = append(data, rec)
+		return err
+	}
+	db.Query(proc, q, args...)
+	return data
+}
+
+func (db *Storage) Query(process rowsProc, q string, args ...interface{}) error {
+	info := "sql.Storage.Query"
+	//log.Debug().Str("query", q).Msg(info)
+	logErr := func(err error) { log.Error(err).Str("query", q).Msg(info) }
+	rows, err := db.DB.Query(q, args...)
+	if err != nil {
+		logErr(err)
+		return err
+	}
+	for rows.Next() {
+		if err := process(rows); err != nil {
+			logErr(err)
+			return err
+		}
+	}
+	if err := rows.Err(); err != nil {
+		logErr(err)
+		return err
+	}
+	return nil
+}
+
 func (db *Storage) Exec(q string, args ...interface{}) (int64, error) {
-	info := "sql.Exec"
+	info := "sql.Storage.Exec"
 	//log.Debug().Str("query", q).Msg(info)
 	res, err := db.DB.Exec(q, args...)
 	if err != nil {

tests/storage_test.go

@@ -33,6 +33,9 @@ func DoTests(t *testing.T, cfg *sql.Cfg, db *sql.Storage) {
 func BaseTest(t *testing.T, cfg *sql.Cfg, db *sql.Storage) {
 	//fmt.Println(cfg.Connstr)
 	db.Exec(insert)
+	data := sql.QueryData[string](db, query, 2)
+	t.AssertEqual(len(data), 1)
+	t.AssertEqual(data[0], "Good Afternoon")
 }
 
 func resetSqlite(db *sql.Storage) {