MDL-71696 core_question: Implement new database schema

This commit implements the new database structure for versioning in question. It also does the migration of current data to the new structure. Co-Authored-By: Safat Shahin <safatshahin@catalyst-au.net> Co-Authored-By: Guillermo Gomez Arias <guillermogomez@catalyst-au.net>
2025-01-17 21:49:15 +01:00 · 2021-06-02 19:16:18 +10:00 · 2021-06-02 19:16:18 +10:00 · c34b89a3c2
commit c34b89a3c2
parent c352b70022
8 changed files with 493 additions and 44 deletions
--- a/lang/en/question.php
+++ b/lang/en/question.php
@ -426,9 +426,11 @@ $string['privacy:metadata:database:question_attempts'] = 'The information about
 $string['privacy:metadata:database:question_attempts:flagged'] = 'An indication that the user has flagged this question within the attempt.';
 $string['privacy:metadata:database:question_attempts:responsesummary'] = 'A summary of the question response.';
 $string['privacy:metadata:database:question_attempts:timemodified'] = 'The time that the question attempt was updated.';
-$string['privacy:metadata:link:qbehaviour'] = 'The question subsystem makes use of the Question behaviours plugin type.';
-$string['privacy:metadata:link:qformat'] = 'The question subsystem makes use of the Question import/export formats plugin type for the purpose of importing and exporting questions in different formats.';
-$string['privacy:metadata:link:qtype'] = 'The question subsystem interacts with the Question types plugin type which contains the different types of questions.';
+$string['privacy:metadata:database:question_bank_entries'] = 'The details about a specific question bank entry.';
+$string['privacy:metadata:database:question_bank_entries:ownerid'] = 'The person who owns the question bank entry.';
+$string['privacy:metadata:link:qbehaviour'] = 'The Question subsystem makes use of the Question Behaviour plugintype.';
+$string['privacy:metadata:link:qformat'] = 'The Question subsystem makes use of the Question Format plugintype for the purpose of importing and exporting questions in different formats.';
+$string['privacy:metadata:link:qtype'] = 'The Question subsystem interacts with the Question Type plugintype which contains the different types of questions.';
 $string['questionbehaviouradminsetting'] = 'Question behaviour settings';
 $string['questionbehavioursdisabled'] = 'Question behaviours to disable';
 $string['questionbehavioursdisabledexplained'] = 'Enter a comma-separated list of behaviours you do not want to appear in the drop-down menu.';
--- a/lib/db/install.xml
+++ b/lib/db/install.xml
@ -1402,10 +1402,9 @@
        <INDEX NAME="contextididnumber" UNIQUE="true" FIELDS="contextid, idnumber"/>
      </INDEXES>
    </TABLE>
-    <TABLE NAME="question" COMMENT="The questions themselves">
+    <TABLE NAME="question" COMMENT="This table stores the definition of one version of a question.">
      <FIELDS>
        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
-        <FIELD NAME="category" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
        <FIELD NAME="parent" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
        <FIELD NAME="name" TYPE="char" LENGTH="255" NOTNULL="true" SEQUENCE="false"/>
        <FIELD NAME="questiontext" TYPE="text" NOTNULL="true" SEQUENCE="false"/>
@ -1417,26 +1416,83 @@
        <FIELD NAME="qtype" TYPE="char" LENGTH="20" NOTNULL="true" SEQUENCE="false"/>
        <FIELD NAME="length" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="1" SEQUENCE="false"/>
        <FIELD NAME="stamp" TYPE="char" LENGTH="255" NOTNULL="true" SEQUENCE="false"/>
-        <FIELD NAME="version" TYPE="char" LENGTH="255" NOTNULL="true" SEQUENCE="false"/>
-        <FIELD NAME="hidden" TYPE="int" LENGTH="1" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
        <FIELD NAME="timecreated" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="time question was created"/>
        <FIELD NAME="timemodified" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="time that question was last modified"/>
        <FIELD NAME="createdby" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="userid of person who created this question"/>
        <FIELD NAME="modifiedby" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="userid of person who last edited this question"/>
-        <FIELD NAME="idnumber" TYPE="char" LENGTH="100" NOTNULL="false" SEQUENCE="false"/>
      </FIELDS>
      <KEYS>
        <KEY NAME="primary" TYPE="primary" FIELDS="id"/>
-        <KEY NAME="category" TYPE="foreign" FIELDS="category" REFTABLE="question_categories" REFFIELDS="id"/>
        <KEY NAME="parent" TYPE="foreign" FIELDS="parent" REFTABLE="question" REFFIELDS="id" COMMENT="note that to make this recursive FK working someday, the parent field must be declared NULL"/>
        <KEY NAME="createdby" TYPE="foreign" FIELDS="createdby" REFTABLE="user" REFFIELDS="id" COMMENT="foreign (createdby) references user (id)"/>
        <KEY NAME="modifiedby" TYPE="foreign" FIELDS="modifiedby" REFTABLE="user" REFFIELDS="id" COMMENT="foreign (modifiedby) references user (id)"/>
      </KEYS>
      <INDEXES>
        <INDEX NAME="qtype" UNIQUE="false" FIELDS="qtype"/>
-        <INDEX NAME="categoryidnumber" UNIQUE="true" FIELDS="category, idnumber"/>
      </INDEXES>
    </TABLE>
+    <TABLE NAME="question_bank_entries" COMMENT="Each question bank entry. This table has one row for each question that appears in the question bank.">
+      <FIELDS>
+        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
+        <FIELD NAME="questioncategoryid" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="ID of the category this question is part of."/>
+        <FIELD NAME="idnumber" TYPE="char" LENGTH="100" NOTNULL="false" SEQUENCE="false" COMMENT="Unique identifier, useful especially for mapping to external entities."/>
+        <FIELD NAME="ownerid" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="userid of person who owns this question bank entry."/>
+      </FIELDS>
+      <KEYS>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id"/>
+        <KEY NAME="questioncategoryid" TYPE="foreign" FIELDS="questioncategoryid" REFTABLE="question_categories" REFFIELDS="id"/>
+        <KEY NAME="ownerid" TYPE="foreign" FIELDS="ownerid" REFTABLE="user" REFFIELDS="id"/>
+      </KEYS>
+      <INDEXES>
+        <INDEX NAME="categoryidnumber" UNIQUE="true" FIELDS="questioncategoryid, idnumber"/>
+      </INDEXES>
+    </TABLE>
+    <TABLE NAME="question_versions" COMMENT="A join table linking the different question version definitions in the question table to the question_bank_entires.">
+      <FIELDS>
+        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
+        <FIELD NAME="questionbankentryid" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="ID of the question bank entry this question version is part of."/>
+        <FIELD NAME="version" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="1" SEQUENCE="false" COMMENT="Version number for the question where the first version is always 1."/>
+        <FIELD NAME="questionid" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="The question ID."/>
+        <FIELD NAME="status" TYPE="char" LENGTH="10" NOTNULL="false" DEFAULT="ready" SEQUENCE="false" COMMENT="If the question is ready, hidden or draft"/>
+      </FIELDS>
+      <KEYS>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id"/>
+        <KEY NAME="questionbankentryid" TYPE="foreign" FIELDS="questionbankentryid" REFTABLE="question_bank_entries" REFFIELDS="id"/>
+        <KEY NAME="questionid" TYPE="foreign" FIELDS="questionid" REFTABLE="question" REFFIELDS="id"/>
+      </KEYS>
+    </TABLE>
+    <TABLE NAME="question_references" COMMENT="Records where a specific question is used.">
+      <FIELDS>
+        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
+        <FIELD NAME="usingcontextid" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="Context where question is used."/>
+        <FIELD NAME="component" TYPE="char" LENGTH="100" NOTNULL="false" SEQUENCE="false" COMMENT="Component (e.g. mod_quiz or core_question)"/>
+        <FIELD NAME="questionarea" TYPE="char" LENGTH="50" NOTNULL="false" SEQUENCE="false" COMMENT="Depending on the component, which area the question is used in (e.g. slot for quiz)."/>
+        <FIELD NAME="itemid" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="Plugin specific id (e.g. slotid for quiz) where its used."/>
+        <FIELD NAME="questionbankentryid" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="ID of the question bank entry this question is part of."/>
+        <FIELD NAME="version" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="Version number for the question where NULL means use the latest ready version."/>
+      </FIELDS>
+      <KEYS>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id"/>
+        <KEY NAME="usingcontextid" TYPE="foreign" FIELDS="usingcontextid" REFTABLE="context" REFFIELDS="id"/>
+        <KEY NAME="questionbankentryid" TYPE="foreign" FIELDS="questionbankentryid" REFTABLE="question_bank_entries" REFFIELDS="id"/>
+      </KEYS>
+    </TABLE>
+    <TABLE NAME="question_set_references" COMMENT="Records where groups of questions are used.">
+      <FIELDS>
+        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
+        <FIELD NAME="usingcontextid" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="Context where question is used."/>
+        <FIELD NAME="component" TYPE="char" LENGTH="100" NOTNULL="false" SEQUENCE="false" COMMENT="Component (e.g. mod_quiz)"/>
+        <FIELD NAME="questionarea" TYPE="char" LENGTH="50" NOTNULL="false" SEQUENCE="false" COMMENT="Depending on the component, which area the question is used in (e.g. slot for quiz)."/>
+        <FIELD NAME="itemid" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="Plugin specific id (e.g. slotid for quiz) where its used."/>
+        <FIELD NAME="questionscontextid" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="Context questions come from."/>
+        <FIELD NAME="filtercondition" TYPE="text" NOTNULL="false" SEQUENCE="false" COMMENT="Filter expression in json format"/>
+      </FIELDS>
+      <KEYS>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id"/>
+        <KEY NAME="usingcontextid" TYPE="foreign" FIELDS="usingcontextid" REFTABLE="context" REFFIELDS="id"/>
+        <KEY NAME="questionscontextid" TYPE="foreign" FIELDS="questionscontextid" REFTABLE="context" REFFIELDS="id"/>
+      </KEYS>
+    </TABLE>
    <TABLE NAME="question_answers" COMMENT="Answers, with a fractional grade (0-1) and feedback">
      <FIELDS>
        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@ -3809,5 +3809,158 @@ privatefiles,moodle|/user/files.php';
        upgrade_main_savepoint(true, 2022012100.02);
    }

+    // Introduce question versioning to core.
+    // First, create the new tables.
+    if ($oldversion < 2022020200.01) {
+        // Define table question_bank_entries to be created.
+        $table = new xmldb_table('question_bank_entries');
+
+        // Adding fields to table question_bank_entries.
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('questioncategoryid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, 0);
+        $table->add_field('idnumber', XMLDB_TYPE_CHAR, '100', null, null, null, null);
+        $table->add_field('ownerid', XMLDB_TYPE_INTEGER, '10', null, null, null, null);
+
+        // Adding keys to table question_bank_entries.
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, ['id']);
+        $table->add_key('questioncategoryid', XMLDB_KEY_FOREIGN, ['questioncategoryid'], 'question_categories', ['id']);
+        $table->add_key('ownerid', XMLDB_KEY_FOREIGN, ['ownerid'], 'user', ['id']);
+
+        // Conditionally launch create table for question_bank_entries.
+        if (!$dbman->table_exists($table)) {
+            $dbman->create_table($table);
+        }
+
+        // Create category id and id number index.
+        $index = new xmldb_index('categoryidnumber', XMLDB_INDEX_UNIQUE, ['questioncategoryid', 'idnumber']);
+
+        // Conditionally launch add index categoryidnumber.
+        if (!$dbman->index_exists($table, $index)) {
+            $dbman->add_index($table, $index);
+        }
+
+        // Define table question_versions to be created.
+        $table = new xmldb_table('question_versions');
+
+        // Adding fields to table question_versions.
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('questionbankentryid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('version', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, 1);
+        $table->add_field('questionid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, 0);
+        $table->add_field('status', XMLDB_TYPE_CHAR, '10', null, XMLDB_NOTNULL, null, 'ready');
+
+        // Adding keys to table question_versions.
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, ['id']);
+        $table->add_key('questionbankentryid', XMLDB_KEY_FOREIGN, ['questionbankentryid'], 'question_bank_entries', ['id']);
+        $table->add_key('questionid', XMLDB_KEY_FOREIGN, ['questionid'], 'question', ['id']);
+
+        // Conditionally launch create table for question_versions.
+        if (!$dbman->table_exists($table)) {
+            $dbman->create_table($table);
+        }
+
+        // Define table question_references to be created.
+        $table = new xmldb_table('question_references');
+
+        // Adding fields to table question_references.
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('usingcontextid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, 0);
+        $table->add_field('component', XMLDB_TYPE_CHAR, '100', null, null, null, null);
+        $table->add_field('questionarea', XMLDB_TYPE_CHAR, '50', null, null, null, null);
+        $table->add_field('itemid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('questionbankentryid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('version', XMLDB_TYPE_INTEGER, '10', null, null, null, null);
+
+        // Adding keys to table question_references.
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, ['id']);
+        $table->add_key('usingcontextid', XMLDB_KEY_FOREIGN, ['usingcontextid'], 'context', ['id']);
+        $table->add_key('questionbankentryid', XMLDB_KEY_FOREIGN, ['questionbankentryid'], 'question_bank_entries', ['id']);
+
+        // Conditionally launch create table for question_references.
+        if (!$dbman->table_exists($table)) {
+            $dbman->create_table($table);
+        }
+
+        // Define table question_set_references to be created.
+        $table = new xmldb_table('question_set_references');
+
+        // Adding fields to table question_set_references.
+        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
+        $table->add_field('usingcontextid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, 0);
+        $table->add_field('component', XMLDB_TYPE_CHAR, '100', null, null, null, null);
+        $table->add_field('questionarea', XMLDB_TYPE_CHAR, '50', null, null, null, null);
+        $table->add_field('itemid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
+        $table->add_field('questionscontextid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, 0);
+        $table->add_field('filtercondition', XMLDB_TYPE_TEXT, null, null, null, null, null);
+
+        // Adding keys to table question_set_references.
+        $table->add_key('primary', XMLDB_KEY_PRIMARY, ['id']);
+        $table->add_key('usingcontextid', XMLDB_KEY_FOREIGN, ['usingcontextid'], 'context', ['id']);
+        $table->add_key('itemid', XMLDB_KEY_FOREIGN, ['itemid'], 'quiz_slots', ['id']);
+        $table->add_key('questionscontextid', XMLDB_KEY_FOREIGN, ['questionscontextid'], 'context', ['id']);
+
+        // Conditionally launch create table for question_set_references.
+        if (!$dbman->table_exists($table)) {
+            $dbman->create_table($table);
+        }
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2022020200.01);
+    }
+
+    if ($oldversion < 2022020200.02) {
+        // Next, split question records into the new tables.
+        upgrade_migrate_question_table();
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2022020200.02);
+    }
+
+    // Finally, drop fields from question table.
+    if ($oldversion < 2022020200.03) {
+        // Define fields to be dropped from questions.
+        $table = new xmldb_table('question');
+
+        $field = new xmldb_field('version');
+        // Conditionally launch drop field version.
+        if ($dbman->field_exists($table, $field)) {
+            $dbman->drop_field($table, $field);
+        }
+
+        $field = new xmldb_field('hidden');
+        // Conditionally launch drop field hidden.
+        if ($dbman->field_exists($table, $field)) {
+            $dbman->drop_field($table, $field);
+        }
+
+        // Define index categoryidnumber (not unique) to be dropped form question.
+        $index = new xmldb_index('categoryidnumber', XMLDB_INDEX_UNIQUE, ['category', 'idnumber']);
+
+        // Conditionally launch drop index categoryidnumber.
+        if ($dbman->index_exists($table, $index)) {
+            $dbman->drop_index($table, $index);
+        }
+
+        // Define key category (foreign) to be dropped form questions.
+        $key = new xmldb_key('category', XMLDB_KEY_FOREIGN, ['category'], 'question_categories', ['id']);
+
+        // Launch drop key category.
+        $dbman->drop_key($table, $key);
+
+        $field = new xmldb_field('idnumber');
+        // Conditionally launch drop field idnumber.
+        if ($dbman->field_exists($table, $field)) {
+            $dbman->drop_field($table, $field);
+        }
+
+        $field = new xmldb_field('category');
+        // Conditionally launch drop field category.
+        if ($dbman->field_exists($table, $field)) {
+            $dbman->drop_field($table, $field);
+        }
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2022020200.03);
+    }
+
    return true;
 }
--- a/lib/db/upgradelib.php
+++ b/lib/db/upgradelib.php
@ -1274,3 +1274,137 @@ function upgrade_calendar_override_events_fix(stdClass $info, bool $output = tru
    upgrade_calendar_events_mtrace('', $output);
    return $return;
 }
+
+/**
+ * Split question table in 2 new tables:
+ *
+ * question_bank_entries
+ * question_versions
+ *
+ * Move the random questions records to the following table:
+ * question_set_reference
+ *
+ * Move the question related records from quiz_slots table to:
+ * question_reference
+ *
+ * Move the tag related data from quiz_slot_tags to:
+ * question_references
+ *
+ * For more information: https://moodle.org/mod/forum/discuss.php?d=417599#p1688163
+ */
+function upgrade_migrate_question_table(): void {
+    global $DB;
+
+    // Maximum size of array.
+    $maxlength = 30000;
+
+    // Array of question_versions objects.
+    $questionversions = [];
+
+    // Array of question_set_references objects.
+    $questionsetreferences = [];
+
+    // The actual update/insert done with multiple DB access, so we do it in a transaction.
+    $transaction = $DB->start_delegated_transaction();
+
+    // Count all questions to be migrated (for progress bar).
+    $total = $DB->count_records('question');
+    $pbar = new progress_bar('migratequestions', 1000, true);
+    $i = 0;
+    // Get all records in question table, we dont need the subquestions, just regular questions and random questions.
+    $questions = $DB->get_recordset('question');
+    foreach ($questions as $question) {
+        upgrade_set_timeout(60);
+        // Populate table question_bank_entries.
+        $questionbankentry = new \stdClass();
+        $questionbankentry->questioncategoryid = $question->category;
+        $questionbankentry->idnumber = $question->idnumber;
+        $questionbankentry->ownerid = $question->createdby;
+        // Insert a question_bank_entries record here as the id is required to populate other tables.
+        $questionbankentry->id = $DB->insert_record('question_bank_entries', $questionbankentry);
+
+        // Create question_versions records to be added.
+        $questionversion = new \stdClass();
+        $questionversion->questionbankentryid = $questionbankentry->id;
+        $questionversion->questionid = $question->id;
+        $questionstatus = \core_question\local\bank\question_version_status::QUESTION_STATUS_READY;
+        if ((int)$question->hidden === 1) {
+            $questionstatus = \core_question\local\bank\question_version_status::QUESTION_STATUS_HIDDEN;
+        }
+        $questionversion->status = $questionstatus;
+        $questionversions[] = $questionversion;
+
+        // Insert the records if the array limit is reached.
+        if (count($questionversions) >= $maxlength) {
+            $DB->insert_records('question_versions', $questionversions);
+            $questionversions = [];
+        }
+
+        // Create question_set_references records to be added.
+        // Only if the question type is random and the question is used in a quiz.
+        if ($question->qtype === 'random') {
+            $quizslots = $DB->get_records('quiz_slots', ['questionid' => $question->id]);
+            foreach ($quizslots as $quizslot) {
+                $questionsetreference = new \stdClass();
+                $cm = get_coursemodule_from_instance('quiz', $quizslot->quizid);
+                $questionsetreference->usingcontextid = context_module::instance($cm->id)->id;
+                $questionsetreference->component = 'mod_quiz';
+                $questionsetreference->questionarea = 'slot';
+                $questionsetreference->itemid = $quizslot->id;
+                $catcontext = $DB->get_field('question_categories', 'contextid', ['id' => $question->category]);
+                $questionsetreference->questionscontextid = $catcontext;
+                // Migration of the slot tags and filter identifiers from slot table to filtercondition.
+                $filtercondition = new stdClass();
+                $filtercondition->questioncategoryid = $question->category;
+                $filtercondition->includingsubcategories = $quizslot->includingsubcategories;
+                $tags = $DB->get_records('quiz_slot_tags', ['slotid' => $quizslot->id]);
+                $tagstrings = [];
+                foreach ($tags as $tag) {
+                    $tagstrings [] = "{$tag->id},{$tag->name}";
+                }
+                if (!empty($tagstrings)) {
+                    $filtercondition->tags = $tagstrings;
+                }
+                $questionsetreference->filtercondition = json_encode($filtercondition);
+
+                $questionsetreferences[] = $questionsetreference;
+
+                // Insert the records if the array limit is reached.
+                if (count($questionsetreferences) >= $maxlength) {
+                    $DB->insert_records('question_set_references', $questionsetreferences);
+                    $questionsetreferences = [];
+                }
+            }
+        }
+        // Update progress.
+        $i++;
+        $pbar->update($i, $total, "Migrating questions - $i/$total.");
+    }
+    $questions->close();
+
+    // Insert the remaining question_versions records.
+    if ($questionversions) {
+        $DB->insert_records('question_versions', $questionversions);
+    }
+
+    // Insert the remaining question_set_references records.
+    if ($questionsetreferences) {
+        $DB->insert_records('question_set_references', $questionsetreferences);
+    }
+
+    // Create question_references record for each question.
+    // Except if qtype is random. That case is handled by question_set_reference.
+    $sql = "INSERT INTO {question_references}
+                        (usingcontextid, component, questionarea, itemid, questionbankentryid)
+                 SELECT c.id, 'mod_quiz', 'slot', qs.id, qv.questionbankentryid
+                   FROM {question} q
+                   JOIN {question_versions} qv ON q.id = qv.questionid
+                   JOIN {quiz_slots} qs ON q.id = qs.questionid
+                   JOIN {modules} m ON m.name = 'quiz'
+                   JOIN {course_modules} cm ON cm.module = m.id AND cm.instance = qs.quizid
+                   JOIN {context} c ON c.instanceid = cm.id AND c.contextlevel = " . CONTEXT_MODULE . "
+                  WHERE q.qtype <> 'random'";
+    $DB->execute($sql);
+
+    $transaction->allow_commit();
+}
--- a/lib/upgrade.txt
+++ b/lib/upgrade.txt
@ -114,8 +114,19 @@ completely removed from Moodle core too.
  Refer to upgrade.php to see transitioning from similar plugin criteria to core
  Refer to completion/upgrade.txt for additional information.
 * The method enable_plugin() has been added to the core_plugininfo\base class and it has been implemented by all the plugininfo
-  classes extending it. When possible, the enable_plugin() method will store these changes into the config_log table, to let admins
-  check when and who has enabled/disabled plugins.
+classes extending it. When possible, the enable_plugin() method will store these changes into the config_log table, to let admins
+check when and who has enabled/disabled plugins.
+* New tables are included as a part of https://docs.moodle.org/dev/Question_bank_improvements_for_Moodle_4.0
+ - question_bank_entries -> Each question bank entry. This table has one row for each question that appears in the question bank.
+ - question_versions -> Versions of the question. Store the data that defines how a particular version of the question works.
+ - question_references -> Records where a specific question is used.
+ - question_set_references -> Records where groups of questions are used (e.g.: Random questions).
+ Also, some tables have been updated or removed:
+ - question (fields migrated to the new tables)
+ - quiz_slot (fields removed)
+ - quiz_slot_tags (table removed)
+ During the upgrade, data from the question table will be copied to the new tables. After this process,
+ the data copied will be removed from question table quiz_slot and finally the the quiz_slot_tags table will be removed.
 * Final deprecation: The following functions along with associated tests have been removed:
  - core_grades_external::get_grades
  - core_grades_external::get_grade_item
--- a/question/classes/local/bank/question_version_status.php
+++ b/question/classes/local/bank/question_version_status.php
@ -0,0 +1,43 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace core_question\local\bank;
+
+/**
+ * Class question_version_status contains the statuses for a question.
+ *
+ * @package    core_question
+ * @copyright  2021 Catalyst IT Australia Pty Ltd
+ * @author     Safat Shahin <safatshahin@catalyst-au.net>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class question_version_status {
+
+    /**
+     * Const if the question is ready to use.
+     */
+    const QUESTION_STATUS_READY = 'ready';
+
+    /**
+     * Const if the question is hidden.
+     */
+    const QUESTION_STATUS_HIDDEN = 'hidden';
+
+    /**
+     * const if the question is in draft.
+     */
+    const QUESTION_STATUS_DRAFT = 'draft';
+}
--- a/question/classes/privacy/provider.php
+++ b/question/classes/privacy/provider.php
@ -126,6 +126,10 @@ class provider implements
        // The 'question_statistics' table contains aggregated statistics about responses.
        // It does not contain any identifiable user data.

+        $items->add_database_table('question_bank_entries', [
+            'ownerid' => 'privacy:metadata:database:question_bank_entries:ownerid',
+        ], 'privacy:metadata:database:question_bank_entries');
+
        // The question subsystem makes use of the qtype, qformat, and qbehaviour plugin types.
        $items->add_plugintype_link('qtype', [], 'privacy:metadata:link:qtype');
        $items->add_plugintype_link('qformat', [], 'privacy:metadata:link:qformat');
@ -336,12 +340,13 @@ class provider implements

        // A user may have created or updated a question.
        // Questions are linked against a question category, which has a contextid field.
-        $sql = "SELECT cat.contextid
+        $sql = "SELECT qc.contextid
                  FROM {question} q
-            INNER JOIN {question_categories} cat ON cat.id = q.category
-                 WHERE
-                    q.createdby = :useridcreated OR
-                   q.modifiedby = :useridmodified";
+                  JOIN {question_versions} qv ON qv.questionid = q.id
+                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
+                  JOIN {question_categories} qc ON qc.id = qbe.questioncategoryid
+                 WHERE q.createdby = :useridcreated
+                       OR q.modifiedby = :useridmodified";
        $params = [
            'useridcreated' => $userid,
            'useridmodified' => $userid,
@ -363,9 +368,10 @@ class provider implements
        // Questions are linked against a question category, which has a contextid field.
        $sql = "SELECT q.createdby, q.modifiedby
                  FROM {question} q
-                  JOIN {question_categories} cat
-                       ON cat.id = q.category
-                 WHERE cat.contextid = :contextid";
+                  JOIN {question_versions} qv ON qv.questionid = q.id
+                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
+                  JOIN {question_categories} qc ON qc.id = qbe.questioncategoryid
+                 WHERE qc.contextid = :contextid";

        $params = [
            'contextid' => $context->id
@ -487,7 +493,8 @@ class provider implements
    /**
     * Delete all data for all users in the specified context.
     *
-     * @param   context                 $context   The specific context to delete data for.
+     * @param \context $context The specific context to delete data for.
+     * @throws \dml_exception
     */
    public static function delete_data_for_all_users_in_context(\context $context) {
        global $DB;
@ -496,17 +503,19 @@ class provider implements
        // user. They are still exported in the list of a users data, but they are not removed.
        // The userid is instead anonymised.

-        $DB->set_field_select('question', 'createdby', 0,
-            'category IN (SELECT id FROM {question_categories} WHERE contextid = :contextid)',
-            [
-                'contextid' => $context->id,
-            ]);
+        $sql = 'SELECT q.*
+                  FROM {question} q
+                  JOIN {question_versions} qv ON qv.questionid = q.id
+                  JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
+                  JOIN {question_categories} qc ON qc.id = qbe.questioncategoryid
+                 WHERE qc.contextid = ?';

-        $DB->set_field_select('question', 'modifiedby', 0,
-            'category IN (SELECT id FROM {question_categories} WHERE contextid = :contextid)',
-            [
-                'contextid' => $context->id,
-            ]);
+        $questions = $DB->get_records_sql($sql, [$context->id]);
+        foreach ($questions as $question) {
+            $question->createdby = 0;
+            $question->modifiedby = 0;
+            $DB->update_record('question', $question);
+        }
    }

    /**
@ -523,15 +532,36 @@ class provider implements

        list($contextsql, $contextparams) = $DB->get_in_or_equal($contextlist->get_contextids(), SQL_PARAMS_NAMED);
        $contextparams['createdby'] = $contextlist->get_user()->id;
-        $DB->set_field_select('question', 'createdby', 0, "
-                category IN (SELECT id FROM {question_categories} WHERE contextid {$contextsql})
-            AND createdby = :createdby", $contextparams);
+        $questiondata = $DB->get_records_sql(
+            "SELECT q.*
+               FROM {question} q
+               JOIN {question_versions} qv ON qv.questionid = q.id
+               JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
+               JOIN {question_categories} qc ON qc.id = qbe.questioncategoryid
+              WHERE qc.contextid {$contextsql}
+                    AND q.createdby = :createdby", $contextparams);
+
+        foreach ($questiondata as $question) {
+            $question->createdby = 0;
+            $DB->update_record('question', $question);
+        }

        list($contextsql, $contextparams) = $DB->get_in_or_equal($contextlist->get_contextids(), SQL_PARAMS_NAMED);
        $contextparams['modifiedby'] = $contextlist->get_user()->id;
-        $DB->set_field_select('question', 'modifiedby', 0, "
-                category IN (SELECT id FROM {question_categories} WHERE contextid {$contextsql})
-            AND modifiedby = :modifiedby", $contextparams);
+        $questiondata = $DB->get_records_sql(
+            "SELECT q.*
+               FROM {question} q
+               JOIN {question_versions} qv ON qv.questionid = q.id
+               JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
+               JOIN {question_categories} qc ON qc.id = qbe.questioncategoryid
+              WHERE qc.contextid {$contextsql}
+                    AND q.modifiedby = :modifiedby", $contextparams);
+
+        foreach ($questiondata as $question) {
+            $question->modifiedby = 0;
+            $DB->update_record('question', $question);
+        }
+
    }

    /**
@ -554,12 +584,32 @@ class provider implements

        $params = ['contextid' => $context->id];

-        $DB->set_field_select('question', 'createdby', 0, "
-                category IN (SELECT id FROM {question_categories} WHERE contextid = :contextid)
-            AND createdby {$createdbysql}", $params + $createdbyparams);
+        $questiondata = $DB->get_records_sql(
+            "SELECT q.*
+               FROM {question} q
+               JOIN {question_versions} qv ON qv.questionid = q.id
+               JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
+               JOIN {question_categories} qc ON qc.id = qbe.questioncategoryid
+              WHERE qc.contextid = :contextid
+                    AND q.createdby {$createdbysql}", $params + $createdbyparams);

-        $DB->set_field_select('question', 'modifiedby', 0, "
-                category IN (SELECT id FROM {question_categories} WHERE contextid = :contextid)
-            AND modifiedby {$modifiedbysql}", $params + $modifiedbyparams);
+        foreach ($questiondata as $question) {
+            $question->createdby = 0;
+            $DB->update_record('question', $question);
+        }
+
+        $questiondata = $DB->get_records_sql(
+            "SELECT q.*
+               FROM {question} q
+               JOIN {question_versions} qv ON qv.questionid = q.id
+               JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid
+               JOIN {question_categories} qc ON qc.id = qbe.questioncategoryid
+              WHERE qc.contextid = :contextid
+                    AND q.modifiedby {$modifiedbysql}", $params + $modifiedbyparams);
+
+        foreach ($questiondata as $question) {
+            $question->modifiedby = 0;
+            $DB->update_record('question', $question);
+        }
    }
 }
--- a/version.php
+++ b/version.php
@ -29,7 +29,7 @@

 defined('MOODLE_INTERNAL') || die();

-$version  = 2022020200.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2022020200.03;              // YYYYMMDD      = weekly release date of this DEV branch.
                                        //         RR    = release increments - 00 in DEV branches.
                                        //           .XX = incremental changes.
 $release  = '4.0dev+ (Build: 20220202)'; // Human-friendly version name