Исходники и презентации

lessons/errors/error_from_defer/main.go

@@ -0,0 +1,21 @@
+package main
+
+import "database/sql"
+
+func getBalance(database *sql.DB, clientId int) (balance float32, err error) {
+	query := "..."
+	var rows *sql.Rows
+	rows, err = database.Query(query, clientId)
+	if err != nil {
+		return 0, err
+	}
+
+	defer func() {
+		if err == nil {
+			err = rows.Close()
+		}
+	}()
+
+	// reading...
+	return balance, err
+}