Mismatched entity and/or field definitions following database update - drupal-8

Question

I have a Drupal site that I'm trying to update to the latest version 8.6.8. The problem is when I run the command 'drush updatedb', I see this error in the console;
Failed: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1-0-0-en' for key 'PRIMARY': INSERT INTO {taxonomy_term__parent} (bundle, entity_id, revision_id, langcode, [error]
delta, parent_target_id) 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, :db_insert_placeholder_9, :db_insert_placeholder_10, :db_insert_placeholder_11),
(:db_insert_placeholder_12, :db_insert_placeholder_13, :db_insert_placeholder_14, :db_insert_placeholder_15, :db_insert_placeholder_16, :db_insert_placeholder_17),
(:db_insert_placeholder_18, :db_insert_placeholder_19, :db_insert_placeholder_20, :db_insert_placeholder_21, :db_insert_placeholder_22, :db_insert_placeholder_23),
(:db_insert_placeholder_24, :db_insert_placeholder_25, :db_insert_placeholder_26, :db_insert_placeholder_27, :db_insert_placeholder_28, :db_insert_placeholder_29),
(:db_insert_placeholder_30, :db_insert_placeholder_31, :db_insert_placeholder_32, :db_insert_placeholder_33, :db_insert_placeholder_34, :db_insert_placeholder_35),
(:db_insert_placeholder_36, :db_insert_placeholder_37, :db_insert_placeholder_38, :db_insert_placeholder_39, :db_insert_placeholder_40, :db_insert_placeholder_41),
(:db_insert_placeholder_42, :db_insert_placeholder_43, :db_insert_placeholder_44, :db_insert_placeholder_45, :db_insert_placeholder_46, :db_insert_placeholder_47),
(:db_insert_placeholder_48, :db_insert_placeholder_49, :db_insert_placeholder_50, :db_insert_placeholder_51, :db_insert_placeholder_52, :db_insert_placeholder_53),
(:db_insert_placeholder_54, :db_insert_placeholder_55, :db_insert_placeholder_56, :db_insert_placeholder_57, :db_insert_placeholder_58, :db_insert_placeholder_59),
(:db_insert_placeholder_60, :db_insert_placeholder_61, :db_insert_placeholder_62, :db_insert_placeholder_63, :db_insert_placeholder_64, :db_insert_placeholder_65),
(:db_insert_placeholder_66, :db_insert_placeholder_67, :db_insert_placeholder_68, :db_insert_placeholder_69, :db_insert_placeholder_70, :db_insert_placeholder_71),
(:db_insert_placeholder_72, :db_insert_placeholder_73, :db_insert_placeholder_74, :db_insert_placeholder_75, :db_insert_placeholder_76, :db_insert_placeholder_77),
(:db_insert_placeholder_78, :db_insert_placeholder_79, :db_insert_placeholder_80, :db_insert_placeholder_81, :db_insert_placeholder_82, :db_insert_placeholder_83),
(:db_insert_placeholder_84, :db_insert_placeholder_85, :db_insert_placeholder_86, :db_insert_placeholder_87, :db_insert_placeholder_88, :db_insert_placeholder_89),
(:db_insert_placeholder_90, :db_insert_placeholder_91, :db_insert_placeholder_92, :db_insert_placeholder_93, :db_insert_placeholder_94, :db_insert_placeholder_95),
(:db_insert_placeholder_96, :db_insert_placeholder_97, :db_insert_placeholder_98, :db_insert_placeholder_99, :db_insert_placeholder_100, :db_insert_placeholder_101)
As a result of this, when I look at the Status Report in Drupal, it shows that there are still database updates outstanding;
Mismatched entity and/or field definitions
The following changes were detected in the entity type and field definitions.
Taxonomy term
The Taxonomy term entity type needs to be updated.
The Published field needs to be installed.
The issue is, I have no idea why this is happening as it's a site I have only recently taken control of from another developer.

Answer 1

Truncating the table 'taxonomy_term__parent' fixed this.

Answer 2

In order to apply Pending Schema Updates.
Try "drush updb" and then
Try running "drush entity-updates".