PDOException: SQLSTATE[22007]: Invalid datetime format: 1366 Incorrect string value: '\xF0\x9F\x93\xB1an...' for column 'body_value' at row 1: INSERT INTO {field_data_body} (entity_type, entity_id, revision_id, bundle, delta, language, body_value, body_summary, body_format) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8); Array ( [:db_insert_placeholder_0] => node [:db_insert_placeholder_1] => 494 [:db_insert_placeholder_2] => 538 [:db_insert_placeholder_3] => blog [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => und [:db_insert_placeholder_6] => <p>I take notes extensively

 

and it turned out that the reason of that error was the Emoji which I was trying to include with text. UTF-8 supposedly doesn't support emojis so one has to post the content without those emojis. ( SOLUTION )