update[DbWrapper]: add exception throwing for SQLException edgecase f…

…or use in testing

src/main/java/edu/group5/app/model/wrapper/DbWrapper.java

@@ -230,8 +230,10 @@ private List<Object[]> importDonations(int user_id, boolean all) {
    * @throws IllegalArgumentException This exception is thrown when data is null, its rows are not
    *      of length 6, any of the rows are null, any of the rows are duplicates or existing rows in
    *      the database, or any of the values in the rows can't be cast to the correct data-types.
+   * @throws SQLException Is thrown when an unexpected exception like trying to export a number that's
+   *      too big happens.
    */
-  public int exportDonations(List<Object[]> data) throws IllegalArgumentException {
+  public int exportDonations(List<Object[]> data) throws IllegalArgumentException, SQLException {
     this.fetchAllDonations();
 
     ParameterValidator.exportChecker(data, "data", this.donations, 6);
@@ -263,6 +265,7 @@ public int exportDonations(List<Object[]> data) throws IllegalArgumentException
       this.logger.info("Donations exported");
     } catch (SQLException e) {
       this.logger.log(Level.SEVERE, "Unexpected SQL exception", e);
+      throw new SQLException("An unexpected SQL exception has occurred. This might be caused by inserting an item that is too large.");
     } finally {
       this.close(null, ps);
     }