public function testDropIndex()
 {
     $DB = $this->tdb;
     // Do not use global $DB!
     $dbman = $this->tdb->get_manager();
     $table = $this->create_deftable('test_table1');
     $index = new xmldb_index('secondname');
     $index->set_attributes(XMLDB_INDEX_NOTUNIQUE, array('course', 'name'));
     $dbman->add_index($table, $index);
     $dbman->drop_index($table, $index);
     $this->assertFalse($dbman->find_index_name($table, $index));
     // Test we are able to drop indexes having hyphens MDL-22804.
     // Create index with hyphens (by hand).
     $indexname = 'test-index-with-hyphens';
     switch ($DB->get_dbfamily()) {
         case 'mysql':
             $indexname = '`' . $indexname . '`';
             break;
         default:
             $indexname = '"' . $indexname . '"';
     }
     $stmt = "CREATE INDEX {$indexname} ON {$DB->get_prefix()}test_table1 (course, name)";
     $DB->change_database_structure($stmt);
     $this->assertNotEmpty($dbman->find_index_name($table, $index));
     // Index created, let's drop it using db manager stuff.
     $index = new xmldb_index('indexname', XMLDB_INDEX_NOTUNIQUE, array('course', 'name'));
     $dbman->drop_index($table, $index);
     $this->assertFalse($dbman->find_index_name($table, $index));
 }

 protected function check_table(xmldb_table $xmldb_table, array $metacolumns)
 {
     global $DB;
     $dbman = $DB->get_manager();
     $o = '';
     $missing_indexes = array();
     // Keys
     if ($xmldb_keys = $xmldb_table->getKeys()) {
         $o .= '        <ul>';
         foreach ($xmldb_keys as $xmldb_key) {
             $o .= '            <li>' . $this->str['key'] . ': ' . $xmldb_key->readableInfo() . ' ';
             // Primaries are skipped
             if ($xmldb_key->getType() == XMLDB_KEY_PRIMARY) {
                 $o .= '<font color="green">' . $this->str['ok'] . '</font></li>';
                 continue;
             }
             // If we aren't creating the keys or the key is a XMLDB_KEY_FOREIGN (not underlying index generated
             // automatically by the RDBMS) create the underlying (created by us) index (if doesn't exists)
             if (!$dbman->generator->getKeySQL($xmldb_table, $xmldb_key) || $xmldb_key->getType() == XMLDB_KEY_FOREIGN) {
                 // Create the interim index
                 $xmldb_index = new xmldb_index('anyname');
                 $xmldb_index->setFields($xmldb_key->getFields());
                 switch ($xmldb_key->getType()) {
                     case XMLDB_KEY_UNIQUE:
                     case XMLDB_KEY_FOREIGN_UNIQUE:
                         $xmldb_index->setUnique(true);
                         break;
                     case XMLDB_KEY_FOREIGN:
                         $xmldb_index->setUnique(false);
                         break;
                 }
                 // Check if the index exists in DB
                 if ($dbman->index_exists($xmldb_table, $xmldb_index)) {
                     $o .= '<font color="green">' . $this->str['ok'] . '</font>';
                 } else {
                     $o .= '<font color="red">' . $this->str['missing'] . '</font>';
                     // Add the missing index to the list
                     $obj = new stdClass();
                     $obj->table = $xmldb_table;
                     $obj->index = $xmldb_index;
                     $missing_indexes[] = $obj;
                 }
             }
             $o .= '</li>';
         }
         $o .= '        </ul>';
     }
     // Indexes
     if ($xmldb_indexes = $xmldb_table->getIndexes()) {
         $o .= '        <ul>';
         foreach ($xmldb_indexes as $xmldb_index) {
             $o .= '            <li>' . $this->str['index'] . ': ' . $xmldb_index->readableInfo() . ' ';
             // Check if the index exists in DB
             if ($dbman->index_exists($xmldb_table, $xmldb_index)) {
                 $o .= '<font color="green">' . $this->str['ok'] . '</font>';
             } else {
                 $o .= '<font color="red">' . $this->str['missing'] . '</font>';
                 // Add the missing index to the list
                 $obj = new stdClass();
                 $obj->table = $xmldb_table;
                 $obj->index = $xmldb_index;
                 $missing_indexes[] = $obj;
             }
             $o .= '</li>';
         }
         $o .= '        </ul>';
     }
     return array($o, $missing_indexes);
 }

//.........这里部分代码省略.........
        $table->add_field('details', XMLDB_TYPE_TEXT, 'big', null, XMLDB_NOTNULL, null, null);
        $table->add_field('timecreated', XMLDB_TYPE_INTEGER, '20', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        /// Adding keys to table block_helpmenow_error_log
        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
        /// Launch create table for block_helpmenow_error_log
        $result = $result && $dbman->create_table($table);
    }
    if ($result && $oldversion < 2012123100) {
        /// Define field userid to be added to block_helpmenow_error_log
        $table = new xmldb_table('block_helpmenow_error_log');
        $field = new xmldb_field('userid');
        $field->set_attributes(XMLDB_TYPE_INTEGER, '20', XMLDB_UNSIGNED, null, null, null, 'timecreated');
        /// Launch add field userid
        $result = $result && $dbman->add_field($table, $field);
    }
    if ($result && $oldversion < 2013011800) {
        /// Define table block_helpmenow_contact to be created
        $table = new xmldb_table('block_helpmenow_contact');
        /// Adding fields to table block_helpmenow_contact
        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
        $table->add_field('userid', XMLDB_TYPE_INTEGER, '20', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        $table->add_field('contact_userid', XMLDB_TYPE_INTEGER, '20', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        $table->add_field('timecreated', XMLDB_TYPE_INTEGER, '20', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        /// Adding keys to table block_helpmenow_contact
        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
        /// Adding indexes to table block_helpmenow_contact
        $table->add_index('block_helpmenow_contact_userid_ix', XMLDB_INDEX_NOTUNIQUE, array('userid'));
        /// Launch create table for block_helpmenow_contact
        $result = $result && $dbman->create_table($table);
    }
    if ($result && $oldversion < 2013050200) {
        /// Define index block_helpmenow_log_u_ix (not unique) to be added to block_helpmenow_log
        $table = new xmldb_table('block_helpmenow_log');
        $index = new xmldb_index('block_helpmenow_log_u_ix');
        $index->set_attributes(XMLDB_INDEX_NOTUNIQUE, array('userid'));
        /// Launch add index block_helpmenow_log_u_ix
        $result = $result && $dbman->add_index($table, $index);
        /// Define index block_helpmenow_log_ua_ix (not unique) to be added to block_helpmenow_log
        $table = new xmldb_table('block_helpmenow_log');
        $index = new xmldb_index('block_helpmenow_log_ua_ix');
        $index->set_attributes(XMLDB_INDEX_NOTUNIQUE, array('userid', 'action'));
        /// Launch add index block_helpmenow_log_ua_ix
        $result = $result && $dbman->add_index($table, $index);
    }
    if ($result && $oldversion < 2013050700) {
        /// Define field last_read to be added to block_helpmenow_session2user
        $table = new xmldb_table('block_helpmenow_session2user');
        $field = new xmldb_field('last_read');
        $field->set_attributes(XMLDB_TYPE_INTEGER, '20', XMLDB_UNSIGNED, null, null, '0', 'cache');
        /// Launch add field last_read
        $result = $result && $dbman->add_field($table, $field);
    }
    if ($result && $oldversion < 2014050401) {
        // Reminder: do not use core/lib function in upgrade script!
        $contextid = $DB->get_field('context', 'id', array('contextlevel' => CONTEXT_SYSTEM));
        // Hardcode the capability as they must match the value at this upgrade time.
        $HELPMENOW_CAP_QUEUE_ANSWER = 'block/helpmenow:global_queue_answer';
        $HELPMENOW_CAP_QUEUE_ASK = 'block/helpmenow:queue_ask';
        $HELPMENOW_CAP_MANAGE = 'block/helpmenow:manage_queues';
        // Add Help Me Now block manager system role.
        $role = new stdClass();
        $role->name = 'Help Me Now Manager';
        $role->shortname = 'helpmenowmanager';
        $role->description = 'can assign a queue helper - can do anything on helpmenow.';
        // Find free sortorder number.
        $role->sortorder = $DB->get_field('role', 'MAX(sortorder) + 1', array());

 /**
  * Invoke method, every class will have its own
  * returns true/false on completion, setting both
  * errormsg and output as necessary
  */
 function invoke()
 {
     parent::invoke();
     $result = true;
     /// Set own core attributes
     $this->does_generate = ACTION_NONE;
     //$this->does_generate = ACTION_GENERATE_HTML;
     /// These are always here
     global $CFG, $XMLDB;
     /// Do the job, setting result as needed
     if (!data_submitted()) {
         ///Basic prevention
         print_error('wrongcall', 'error');
     }
     /// Get parameters
     $dirpath = required_param('dir', PARAM_PATH);
     $dirpath = $CFG->dirroot . $dirpath;
     $tableparam = strtolower(required_param('table', PARAM_PATH));
     $indexparam = strtolower(required_param('index', PARAM_PATH));
     $name = trim(strtolower(optional_param('name', $indexparam, PARAM_PATH)));
     $comment = required_param('comment', PARAM_CLEAN);
     $comment = trim($comment);
     $unique = required_param('unique', PARAM_INT);
     $fields = required_param('fields', PARAM_CLEAN);
     $fields = str_replace(' ', '', trim(strtolower($fields)));
     $editeddir =& $XMLDB->editeddirs[$dirpath];
     $structure =& $editeddir->xml_file->getStructure();
     $table =& $structure->getTable($tableparam);
     $index =& $table->getIndex($indexparam);
     $oldhash = $index->getHash();
     $errors = array();
     /// To store all the errors found
     /// Perform some checks
     /// Check empty name
     if (empty($name)) {
         $errors[] = $this->str['indexnameempty'];
     }
     /// Check incorrect name
     if ($name == 'changeme') {
         $errors[] = $this->str['incorrectindexname'];
     }
     /// Check duplicate name
     if ($indexparam != $name && $table->getIndex($name)) {
         $errors[] = $this->str['duplicateindexname'];
     }
     $fieldsarr = explode(',', $fields);
     /// Check the fields isn't empty
     if (empty($fieldsarr[0])) {
         $errors[] = $this->str['nofieldsspecified'];
     } else {
         /// Check that there aren't duplicate column names
         $uniquearr = array_unique($fieldsarr);
         if (count($fieldsarr) != count($uniquearr)) {
             $errors[] = $this->str['duplicatefieldsused'];
         }
         /// Check that all the fields in belong to the table
         foreach ($fieldsarr as $field) {
             if (!$table->getField($field)) {
                 $errors[] = $this->str['fieldsnotintable'];
                 break;
             }
         }
         /// Check that there isn't any key using exactly the same fields
         $tablekeys = $table->getKeys();
         if ($tablekeys) {
             foreach ($tablekeys as $tablekey) {
                 $keyfieldsarr = $tablekey->getFields();
                 /// Compare both arrays, looking for diferences
                 $diferences = array_merge(array_diff($fieldsarr, $keyfieldsarr), array_diff($keyfieldsarr, $fieldsarr));
                 if (empty($diferences)) {
                     $errors[] = $this->str['fieldsusedinkey'];
                     break;
                 }
             }
         }
         /// Check that there isn't any index using exactlt the same fields
         $tableindexes = $table->getIndexes();
         if ($tableindexes) {
             foreach ($tableindexes as $tableindex) {
                 /// Skip checking against itself
                 if ($indexparam == $tableindex->getName()) {
                     continue;
                 }
                 $indexfieldsarr = $tableindex->getFields();
                 /// Compare both arrays, looking for diferences
                 $diferences = array_merge(array_diff($fieldsarr, $indexfieldsarr), array_diff($indexfieldsarr, $fieldsarr));
                 if (empty($diferences)) {
                     $errors[] = $this->str['fieldsusedinindex'];
                     break;
                 }
             }
         }
     }
     if (!empty($errors)) {
         $tempindex = new xmldb_index($name);
//.........这里部分代码省略.........

//.........这里部分代码省略.........
             $this->debug($this->errormsg);
             $result = false;
         }
     }
     /// Iterate over keys
     if (isset($xmlarr['#']['KEYS']['0']['#']['KEY'])) {
         foreach ($xmlarr['#']['KEYS']['0']['#']['KEY'] as $xmlkey) {
             if (!$result) {
                 //Skip on error
                 continue;
             }
             $name = trim($xmlkey['@']['NAME']);
             $key = new xmldb_key($name);
             $key->arr2xmldb_key($xmlkey);
             $this->keys[] = $key;
             if (!$key->isLoaded()) {
                 $this->errormsg = 'Problem loading key ' . $name;
                 $this->debug($this->errormsg);
                 $result = false;
             }
         }
     } else {
         $this->errormsg = 'Missing KEYS section (at least one PK must exist)';
         $this->debug($this->errormsg);
         $result = false;
     }
     /// Perform some general checks over keys
     if ($result && $this->keys) {
         /// Check keys names are ok (lowercase, a-z _-)
         if (!$this->checkNameValues($this->keys)) {
             $this->errormsg = 'Some KEYS name values are incorrect';
             $this->debug($this->errormsg);
             $result = false;
         }
         /// Check previous & next are ok (duplicates and existing keys)
         $this->fixPrevNext($this->keys);
         if ($result && !$this->checkPreviousNextValues($this->keys)) {
             $this->errormsg = 'Some KEYS previous/next values are incorrect';
             $this->debug($this->errormsg);
             $result = false;
         }
         /// Order keys
         if ($result && !$this->orderKeys($this->keys)) {
             $this->errormsg = 'Error ordering the keys';
             $this->debug($this->errormsg);
             $result = false;
         }
         /// TODO: Only one PK
         /// TODO: Not keys with repeated fields
         /// TODO: Check fields and reffieds exist in table
     }
     /// Iterate over indexes
     if (isset($xmlarr['#']['INDEXES']['0']['#']['INDEX'])) {
         foreach ($xmlarr['#']['INDEXES']['0']['#']['INDEX'] as $xmlindex) {
             if (!$result) {
                 //Skip on error
                 continue;
             }
             $name = trim($xmlindex['@']['NAME']);
             $index = new xmldb_index($name);
             $index->arr2xmldb_index($xmlindex);
             $this->indexes[] = $index;
             if (!$index->isLoaded()) {
                 $this->errormsg = 'Problem loading index ' . $name;
                 $this->debug($this->errormsg);
                 $result = false;
             }
         }
     }
     /// Perform some general checks over indexes
     if ($result && $this->indexes) {
         /// Check field names are ok (lowercase, a-z _-)
         if (!$this->checkNameValues($this->indexes)) {
             $this->errormsg = 'Some INDEXES name values are incorrect';
             $this->debug($this->errormsg);
             $result = false;
         }
         /// Check previous & next are ok (duplicates and existing INDEXES)
         $this->fixPrevNext($this->indexes);
         if ($result && !$this->checkPreviousNextValues($this->indexes)) {
             $this->errormsg = 'Some INDEXES previous/next values are incorrect';
             $this->debug($this->errormsg);
             $result = false;
         }
         /// Order indexes
         if ($result && !$this->orderIndexes($this->indexes)) {
             $this->errormsg = 'Error ordering the indexes';
             $this->debug($this->errormsg);
             $result = false;
         }
         /// TODO: Not indexes with repeated fields
         /// TODO: Check fields exist in table
     }
     /// Set some attributes
     if ($result) {
         $this->loaded = true;
     }
     $this->calculateHash();
     return $result;
 }

//.........这里部分代码省略.........
         $test = new stdClass();
         $field = new xmldb_field('secondname');
         $field->set_attributes(XMLDB_TYPE_CHAR, '10', null, XMLDB_NOTNULL, null, 'Moodle2');
         $test->sql = $gen->getModifyDefaultSQL($table, $field);
         try {
             $dbman->change_field_default($table, $field, false, false);
             $test->status = true;
         } catch (moodle_exception $e) {
             $test->status = false;
             $test->error = $DB->get_last_error() . "\n" . $e;
         }
         $tests['add field default of NOT NULL field'] = $test;
     }
     /// 26th test. Dropping the default of one NOT NULL field
     if ($test->status) {
         /// Get SQL code and execute it
         $test = new stdClass();
         $field = new xmldb_field('secondname');
         $field->set_attributes(XMLDB_TYPE_CHAR, '10', null, XMLDB_NOTNULL, null, null);
         $test->sql = $gen->getModifyDefaultSQL($table, $field);
         try {
             $dbman->change_field_default($table, $field, false, false);
             $test->status = true;
         } catch (moodle_exception $e) {
             $test->status = false;
             $test->error = $DB->get_last_error() . "\n" . $e;
         }
         $tests['drop field default of NOT NULL field'] = $test;
     }
     /// 27th test. Adding one unique index to the table
     if ($test->status) {
         /// Get SQL code and execute it
         $test = new stdClass();
         $index = new xmldb_index('secondname');
         $index->set_attributes(XMLDB_INDEX_UNIQUE, array('name', 'secondname', 'grade'));
         $test->sql = $gen->getAddIndexSQL($table, $index);
         try {
             $dbman->add_index($table, $index, false, false);
             $test->status = true;
         } catch (moodle_exception $e) {
             $test->status = false;
             $test->error = $DB->get_last_error() . "\n" . $e;
         }
         $tests['add unique index'] = $test;
     }
     /// 28th test. Adding one not unique index to the table
     if ($test->status) {
         /// Get SQL code and execute it
         $test = new stdClass();
         $index = new xmldb_index('secondname');
         $index->set_attributes(XMLDB_INDEX_NOTUNIQUE, array('course', 'name'));
         $test->sql = $gen->getAddIndexSQL($table, $index);
         try {
             $dbman->add_index($table, $index, false, false);
             $test->status = true;
         } catch (moodle_exception $e) {
             $test->status = false;
             $test->error = $DB->get_last_error() . "\n" . $e;
         }
         $tests['add not unique index'] = $test;
     }
     /// 29th test. Re-add the same index than previous test. Check find_index_name() works.
     if ($test->status) {
         /// Get SQL code and execute it
         $test = new stdClass();
         $index = new xmldb_index('secondname');

//.........这里部分代码省略.........
        if ($dbman->field_exists($table, $field)) {
            $result = $result && $dbman->drop_field($table, $field, false, true);
        }
    }
    // 2.0 upgrade line.
    if ($oldversion < 2011120701) {
        // Update existing select fields to use new seperator.
        $badrows = $DB->get_records_sql("\n                SELECT\n                    *\n                FROM\n                    {facetoface_session_field}\n                WHERE\n                    possiblevalues LIKE '%;%'\n                AND possiblevalues NOT LIKE '%" . CUSTOMFIELD_DELIMITER . "%'\n                AND type IN (" . CUSTOMFIELD_TYPE_SELECT . "," . CUSTOMFIELD_TYPE_MULTISELECT . ")\n            ");
        if ($badrows) {
            $transaction = $DB->start_delegated_transaction();
            foreach ($badrows as $bad) {
                $fixedrow = new stdClass();
                $fixedrow->id = $bad->id;
                $fixedrow->possiblevalues = str_replace(';', CUSTOMFIELD_DELIMITER, $bad->possiblevalues);
                $DB->update_record('facetoface_session_field', $fixedrow);
            }
            $transaction->allow_commit();
        }
        $baddatarows = $DB->get_records_sql("\n                SELECT\n                    sd.id, sd.data\n                FROM\n                    {facetoface_session_field} sf\n                JOIN\n                    {facetoface_session_data} sd\n                  ON\n                    sd.fieldid=sf.id\n                WHERE\n                    sd.data LIKE '%;%'\n                AND sd.data NOT LIKE '%" . CUSTOMFIELD_DELIMITER . "%'\n                AND sf.type = " . CUSTOMFIELD_TYPE_MULTISELECT);
        if ($baddatarows) {
            $transaction = $DB->start_delegated_transaction();
            foreach ($baddatarows as $bad) {
                $fixedrow = new stdClass();
                $fixedrow->id = $bad->id;
                $fixedrow->data = str_replace(';', CUSTOMFIELD_DELIMITER, $bad->data);
                $DB->update_record('facetoface_session_data', $fixedrow);
            }
            $transaction->allow_commit();
        }
        upgrade_mod_savepoint(true, 2011120701, 'facetoface');
    }
    if ($oldversion < 2011120702) {
        $table = new xmldb_table('facetoface_session_field');
        $index = new xmldb_index('ind_session_field_unique');
        $index->set_attributes(XMLDB_INDEX_UNIQUE, array('shortname'));
        if ($dbman->table_exists($table)) {
            // Do we need to check for duplicates?
            if (!$dbman->index_exists($table, $index)) {
                // Check for duplicate records and make them unique.
                $replacements = array();
                $transaction = $DB->start_delegated_transaction();
                $sql = 'SELECT
                            l.id,
                            l.shortname
                        FROM
                            {facetoface_session_field} l,
                            ( SELECT
                                    MIN(id) AS id,
                                    shortname
                              FROM
                                    {facetoface_session_field}
                              GROUP BY
                                    shortname
                              HAVING COUNT(*)>1
                             ) a
                        WHERE
                            l.id<>a.id
                        AND l.shortname = a.shortname
                ';
                $rs = $DB->get_recordset_sql($sql, null);
                if ($rs !== false) {
                    foreach ($rs as $item) {
                        $data = (object) $item;
                        // Randomize the value.
                        $data->shortname = $DB->escape($data->shortname . '_' . $data->id);
                        $DB->update_record('facetoface_session_field', $data);

/**
 *
 * @global stdClass $CFG
 * @global stdClass $USER
 * @global moodle_database $DB
 * @global core_renderer $OUTPUT
 * @param int $oldversion
 * @return bool always true
 */
function xmldb_main_upgrade($oldversion)
{
    global $CFG, $USER, $DB, $OUTPUT;
    require_once $CFG->libdir . '/db/upgradelib.php';
    // Core Upgrade-related functions
    $dbman = $DB->get_manager();
    // loads ddl manager and xmldb classes
    ////////////////////////////////////////
    ///upgrade supported only from 1.9.x ///
    ////////////////////////////////////////
    if ($oldversion < 2008030600) {
        //NOTE: this table was added much later later in dev cycle, but we need it here, upgrades from pre PR1 not supported
        /// Define table upgrade_log to be created
        $table = new xmldb_table('upgrade_log');
        /// Adding fields to table upgrade_log
        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
        $table->add_field('type', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
        $table->add_field('plugin', XMLDB_TYPE_CHAR, '100', null, null, null, null);
        $table->add_field('version', XMLDB_TYPE_CHAR, '100', null, null, null, null);
        $table->add_field('targetversion', XMLDB_TYPE_CHAR, '100', null, null, null, null);
        $table->add_field('info', XMLDB_TYPE_CHAR, '255', null, XMLDB_NOTNULL, null, null);
        $table->add_field('details', XMLDB_TYPE_TEXT, 'small', null, null, null, null);
        $table->add_field('backtrace', XMLDB_TYPE_TEXT, 'small', null, null, null, null);
        $table->add_field('userid', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        $table->add_field('timemodified', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        /// Adding keys to table upgrade_log
        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
        $table->add_key('userid', XMLDB_KEY_FOREIGN, array('userid'), 'user', array('id'));
        /// Adding indexes to table upgrade_log
        $table->add_index('timemodified', XMLDB_INDEX_NOTUNIQUE, array('timemodified'));
        $table->add_index('type-timemodified', XMLDB_INDEX_NOTUNIQUE, array('type', 'timemodified'));
        /// Create table for upgrade_log
        $dbman->create_table($table);
        /// Main savepoint reached
        upgrade_main_savepoint(true, 2008030600);
    }
    if ($oldversion < 2008030601) {
        //NOTE: this table was added much later later in dev cycle, but we need it here, upgrades from pre PR1 not supported
        /// Define table log_queries to be created
        $table = new xmldb_table('log_queries');
        /// Adding fields to table log_queries
        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
        $table->add_field('qtype', XMLDB_TYPE_INTEGER, '5', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        $table->add_field('sqltext', XMLDB_TYPE_TEXT, 'medium', null, XMLDB_NOTNULL, null, null);
        $table->add_field('sqlparams', XMLDB_TYPE_TEXT, 'big', null, null, null, null);
        $table->add_field('error', XMLDB_TYPE_INTEGER, '5', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0');
        $table->add_field('info', XMLDB_TYPE_TEXT, 'small', null, null, null, null);
        $table->add_field('backtrace', XMLDB_TYPE_TEXT, 'small', null, null, null, null);
        $table->add_field('exectime', XMLDB_TYPE_NUMBER, '10, 5', null, XMLDB_NOTNULL, null, null);
        $table->add_field('timelogged', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        /// Adding keys to table log_queries
        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
        /// Conditionally launch create table for log_queries
        $dbman->create_table($table);
        /// Main savepoint reached
        upgrade_main_savepoint(true, 2008030601);
    }
    if ($oldversion < 2008030602) {
        @unlink($CFG->dataroot . '/cache/languages');
        if (file_exists("{$CFG->dataroot}/lang")) {
            // rename old lang directory so that the new and old langs do not mix
            if (rename("{$CFG->dataroot}/lang", "{$CFG->dataroot}/oldlang")) {
                $oldlang = "{$CFG->dataroot}/oldlang";
            } else {
                $oldlang = "{$CFG->dataroot}/lang";
            }
        } else {
            $oldlang = '';
        }
        // TODO: fetch previously installed languages ("*_utf8") found in $oldlang from moodle.org
        upgrade_set_timeout(60 * 20);
        // this may take a while
        // TODO: add some info file to $oldlang describing what to do with "$oldlang/*_utf8_local" dirs
        // Main savepoint reached
        upgrade_main_savepoint(true, 2008030602);
    }
    if ($oldversion < 2008030700) {
        upgrade_set_timeout(60 * 20);
        // this may take a while
        /// Define index contextid-lowerboundary (not unique) to be dropped form grade_letters
        $table = new xmldb_table('grade_letters');
        $index = new xmldb_index('contextid-lowerboundary', XMLDB_INDEX_NOTUNIQUE, array('contextid', 'lowerboundary'));
        /// Launch drop index contextid-lowerboundary
        if ($dbman->index_exists($table, $index)) {
            $dbman->drop_index($table, $index);
        }
        /// Define index contextid-lowerboundary-letter (unique) to be added to grade_letters
        $table = new xmldb_table('grade_letters');
        $index = new xmldb_index('contextid-lowerboundary-letter', XMLDB_INDEX_UNIQUE, array('contextid', 'lowerboundary', 'letter'));
        /// Launch add index contextid-lowerboundary-letter
        $dbman->add_index($table, $index);
//.........这里部分代码省略.........

//.........这里部分代码省略.........
        $dbman->drop_field($table, $field);
        // Questionnaire savepoint reached.
        upgrade_mod_savepoint(true, 2008031905, 'questionnaire');
    }
    if ($oldversion < 2008031906) {
        $table = new xmldb_table('questionnaire_response_rank');
        $field = new xmldb_field('rank');
        $field->set_attributes(XMLDB_TYPE_INTEGER, '11', null, XMLDB_NOTNULL, null, null, null, '0', 'choice_id');
        $field->setUnsigned(false);
        $dbman->change_field_unsigned($table, $field);
        // Questionnaire savepoint reached.
        upgrade_mod_savepoint(true, 2008031906, 'questionnaire');
    }
    if ($oldversion < 2008060401) {
        $table = new xmldb_table('questionnaire_question');
        $field = new xmldb_field('name');
        $field->set_attributes(XMLDB_TYPE_CHAR, '30', null, XMLDB_NOTNULL, null, null, null, null, 'survey_id');
        $field->setNotnull(false);
        $dbman->change_field_notnull($table, $field);
        // Questionnaire savepoint reached.
        upgrade_mod_savepoint(true, 2008060401, 'questionnaire');
    }
    if ($oldversion < 2008070702) {
        $table = new xmldb_table('questionnaire_question_type');
        $field = new xmldb_field('response_table');
        $field->set_attributes(XMLDB_TYPE_CHAR, '32', null, XMLDB_NOTNULL, null, null, null, null, 'has_choices');
        $field->setNotnull(false);
        $dbman->change_field_notnull($table, $field);
        // Questionnaire savepoint reached.
        upgrade_mod_savepoint(true, 2008070702, 'questionnaire');
    }
    if ($oldversion < 2008070703) {
        $table = new xmldb_table('questionnaire_resp_multiple');
        $index = new xmldb_index('response_question');
        $index->set_attributes(XMLDB_INDEX_NOTUNIQUE, array('response_id', 'question_id', 'choice_id'));
        if (!$dbman->index_exists($table, $index)) {
            $dbman->add_index($table, $index);
        }
        // Questionnaire savepoint reached.
        upgrade_mod_savepoint(true, 2008070703, 'questionnaire');
    }
    if ($oldversion < 2008070704) {
        // CONTRIB-1542.
        $table = new xmldb_table('questionnaire_survey');
        $field = new xmldb_field('email');
        $field->set_attributes(XMLDB_TYPE_CHAR, '64', null, XMLDB_NOTNULL, null, null, null, null, 'title');
        $field->setLength('255');
        $dbman->change_field_precision($table, $field);
        // Questionnaire savepoint reached.
        upgrade_mod_savepoint(true, 2008070704, 'questionnaire');
    }
    if ($oldversion < 2008070705) {
        // Rename summary field to 'intro' to adhere to new Moodle standard.
        $table = new xmldb_table('questionnaire');
        $field = new xmldb_field('summary');
        $field->set_attributes(XMLDB_TYPE_TEXT, 'small', null, XMLDB_NOTNULL, null, null, null, null, 'name');
        $dbman->rename_field($table, $field, 'intro');
        // Add 'introformat' to adhere to new Moodle standard.
        $field = new xmldb_field('introformat', XMLDB_TYPE_INTEGER, '4', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0', 'intro');
        $dbman->add_field($table, $field);
        // Set all existing records to HTML format.
        $DB->set_field('questionnaire', 'introformat', 1);
        // Questionnaire savepoint reached.
        upgrade_mod_savepoint(true, 2008070705, 'questionnaire');
    }
    if ($oldversion < 2008070706) {

function xmldb_teambuilder_upgrade($oldversion = 0)
{
    global $CFG, $DB;
    $dbman = $DB->get_manager();
    /// And upgrade begins here. For each one, you'll need one
    /// block of code similar to the next one. Please, delete
    /// this comment lines once this file start handling proper
    /// upgrade code.
    /// if ($result && $oldversion < YYYYMMDD00) { //New version in version.php
    ///     $result = result of "/lib/ddllib.php" function calls
    /// }
    /// Lines below (this included)  MUST BE DELETED once you get the first version
    /// of your module ready to be installed. They are here only
    /// for demonstrative purposes and to show how the teambuilder
    /// iself has been upgraded.
    /// For each upgrade block, the file teambuilder/version.php
    /// needs to be updated . Such change allows Moodle to know
    /// that this file has to be processed.
    /// To know more about how to write correct DB upgrade scripts it's
    /// highly recommended to read information available at:
    ///   http://docs.moodle.org/en/Development:XMLDB_Documentation
    /// and to play with the XMLDB Editor (in the admin menu) and its
    /// PHP generation posibilities.
    /// First example, some fields were added to the module on 20070400
    if ($oldversion < 2007040100) {
        /// Define field course to be added to teambuilder
        $table = new xmldb_table('teambuilder');
        $field = new xmldb_field('course');
        $field->set_attributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0', 'id');
        /// Launch add field course
        $dbman->add_field($table, $field);
        /// Define field intro to be added to teambuilder
        $table = new xmldb_table('teambuilder');
        $field = new xmldb_field('intro');
        $field->set_attributes(XMLDB_TYPE_TEXT, 'medium', null, null, null, null, 'name');
        /// Launch add field intro
        $dbman->add_field($table, $field);
        /// Define field introformat to be added to teambuilder
        $table = new xmldb_table('teambuilder');
        $field = new xmldb_field('introformat');
        $field->set_attributes(XMLDB_TYPE_INTEGER, '4', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0', 'intro');
        /// Launch add field introformat
        $dbman->add_field($table, $field);
        upgrade_mod_savepoint(true, 2007040100, 'teambuilder');
    }
    /// Second example, some hours later, the same day 20070401
    /// two more fields and one index were added (note the increment
    /// "01" in the last two digits of the version
    if ($oldversion < 2007040101) {
        /// Define field timecreated to be added to teambuilder
        $table = new xmldb_table('teambuilder');
        $field = new xmldb_field('timecreated');
        $field->set_attributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0', 'introformat');
        /// Launch add field timecreated
        $dbman->add_field($table, $field);
        /// Define field timemodified to be added to teambuilder
        $table = new xmldb_table('teambuilder');
        $field = new xmldb_field('timemodified');
        $field->set_attributes(XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0', 'timecreated');
        /// Launch add field timemodified
        $dbman->add_field($table, $field);
        /// Define index course (not unique) to be added to teambuilder
        $table = new xmldb_table('teambuilder');
        $index = new xmldb_index('course');
        $index->set_attributes(XMLDB_INDEX_NOTUNIQUE, array('course'));
        /// Launch add index course
        $dbman->add_index($table, $index);
        upgrade_mod_savepoint(true, 2007040101, 'teambuilder');
    }
    /// Third example, the next day, 20070402 (with the trailing 00), some inserts were performed, related with the module
    if ($oldversion < 2007040200) {
        /// Add some actions to get them properly displayed in the logs
        $rec = new stdClass();
        $rec->module = 'teambuilder';
        $rec->action = 'add';
        $rec->mtable = 'teambuilder';
        $rec->filed = 'name';
        /// Insert the add action in log_display
        $DB->insert_record('log_display', $rec);
        /// Now the update action
        $rec->action = 'update';
        $DB->insert_record('log_display', $rec);
        /// Now the view action
        $rec->action = 'view';
        $DB->insert_record('log_display', $rec);
        upgrade_mod_savepoint(true, 2007040200, 'teambuilder');
    }
    if ($oldversion < 2011051702) {
        $table = new xmldb_table('teambuilder');
        $field = new xmldb_field('introformat', XMLDB_TYPE_INTEGER, '4', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0', 'intro');
        // Launch add field introformat
        if (!$dbman->field_exists($table, $field)) {
            $dbman->add_field($table, $field);
        }
        upgrade_mod_savepoint(true, 2011051702, 'teambuilder');
    }
    /// And that's all. Please, examine and understand the 3 example blocks above. Also
    /// it's interesting to look how other modules are using this script. Remember that
    /// the basic idea is to have "blocks" of code (each one being executed only once,
    /// when the module version (version.php) is updated.
//.........这里部分代码省略.........

function xmldb_main_upgrade($oldversion)
{
    global $CFG, $THEME, $USER, $DB, $OUTPUT;
    require_once $CFG->libdir . '/db/upgradelib.php';
    // Core Upgrade-related functions
    $result = true;
    $dbman = $DB->get_manager();
    // loads ddl manager and xmldb classes
    ////////////////////////////////////////
    ///upgrade supported only from 1.9.x ///
    ////////////////////////////////////////
    if ($result && $oldversion < 2008030600) {
        //NOTE: this table was added much later, that is why this step is repeated later in this file
        /// Define table upgrade_log to be created
        $table = new xmldb_table('upgrade_log');
        /// Adding fields to table upgrade_log
        $table->add_field('id', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
        $table->add_field('type', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
        $table->add_field('plugin', XMLDB_TYPE_CHAR, '100', null, null, null, null);
        $table->add_field('version', XMLDB_TYPE_CHAR, '100', null, null, null, null);
        $table->add_field('info', XMLDB_TYPE_CHAR, '255', null, XMLDB_NOTNULL, null, null);
        $table->add_field('details', XMLDB_TYPE_TEXT, 'small', null, null, null, null);
        $table->add_field('backtrace', XMLDB_TYPE_TEXT, 'small', null, null, null, null);
        $table->add_field('userid', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        $table->add_field('timemodified', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, null);
        /// Adding keys to table upgrade_log
        $table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
        $table->add_key('userid', XMLDB_KEY_FOREIGN, array('userid'), 'user', array('id'));
        /// Adding indexes to table upgrade_log
        $table->add_index('timemodified', XMLDB_INDEX_NOTUNIQUE, array('timemodified'));
        $table->add_index('type-timemodified', XMLDB_INDEX_NOTUNIQUE, array('type', 'timemodified'));
        /// Create table for upgrade_log
        $dbman->create_table($table);
        /// Main savepoint reached
        upgrade_main_savepoint($result, 2008030600);
    }
    if ($result && $oldversion < 2008030700) {
        upgrade_set_timeout(60 * 20);
        // this may take a while
        /// Define index contextid-lowerboundary (not unique) to be dropped form grade_letters
        $table = new xmldb_table('grade_letters');
        $index = new xmldb_index('contextid-lowerboundary', XMLDB_INDEX_NOTUNIQUE, array('contextid', 'lowerboundary'));
        /// Launch drop index contextid-lowerboundary
        $dbman->drop_index($table, $index);
        /// Define index contextid-lowerboundary-letter (unique) to be added to grade_letters
        $table = new xmldb_table('grade_letters');
        $index = new xmldb_index('contextid-lowerboundary-letter', XMLDB_INDEX_UNIQUE, array('contextid', 'lowerboundary', 'letter'));
        /// Launch add index contextid-lowerboundary-letter
        $dbman->add_index($table, $index);
        /// Main savepoint reached
        upgrade_main_savepoint($result, 2008030700);
    }
    if ($result && $oldversion < 2008050100) {
        // Update courses that used weekscss to weeks
        $result = $DB->set_field('course', 'format', 'weeks', array('format' => 'weekscss'));
        upgrade_main_savepoint($result, 2008050100);
    }
    if ($result && $oldversion < 2008050200) {
        // remove unused config options
        unset_config('statsrolesupgraded');
        upgrade_main_savepoint($result, 2008050200);
    }
    if ($result && $oldversion < 2008050700) {
        upgrade_set_timeout(60 * 20);
        // this may take a while
        /// Fix minor problem caused by MDL-5482.
        require_once $CFG->dirroot . '/question/upgrade.php';
        $result = $result && question_fix_random_question_parents();
        upgrade_main_savepoint($result, 2008050700);
    }
    if ($result && $oldversion < 2008051200) {
        // if guest role used as default user role unset it and force admin to choose new setting
        if (!empty($CFG->defaultuserroleid)) {
            if ($role = $DB->get_record('role', array('id' => $CFG->defaultuserroleid))) {
                if ($guestroles = get_roles_with_capability('moodle/legacy:guest', CAP_ALLOW)) {
                    if (isset($guestroles[$role->id])) {
                        set_config('defaultuserroleid', null);
                        echo $OUTPUT->notification('Guest role removed from "Default role for all users" setting, please select another role.', 'notifysuccess');
                    }
                }
            } else {
                set_config('defaultuserroleid', null);
            }
        }
        /// Main savepoint reached
        upgrade_main_savepoint($result, 2008051200);
    }
    if ($result && $oldversion < 2008051201) {
        echo $OUTPUT->notification('Increasing size of user idnumber field, this may take a while...', 'notifysuccess');
        upgrade_set_timeout(60 * 20);
        // this may take a while
        /// Under MySQL and Postgres... detect old NULL contents and change them by correct empty string. MDL-14859
        $dbfamily = $DB->get_dbfamily();
        if ($dbfamily === 'mysql' || $dbfamily === 'postgres') {
            $DB->execute("UPDATE {user} SET idnumber = '' WHERE idnumber IS NULL");
        }
        /// Define index idnumber (not unique) to be dropped form user
        $table = new xmldb_table('user');
        $index = new xmldb_index('idnumber', XMLDB_INDEX_NOTUNIQUE, array('idnumber'));
        /// Launch drop index idnumber
//.........这里部分代码省略.........

function xmldb_block_lockdownbrowser_upgrade($oldversion = 0)
{
    global $DB;
    $dbman = $DB->get_manager();
    if ($oldversion < 2012082000) {
        // table names limited to 28 characters in Moodle 2.3+
        $table = new xmldb_table("block_lockdownbrowser_settings");
        if ($dbman->table_exists($table)) {
            $dbman->rename_table($table, "block_lockdownbrowser_sett");
        }
        $table = new xmldb_table("block_lockdownbrowser_tokens");
        if ($dbman->table_exists($table)) {
            $dbman->rename_table($table, "block_lockdownbrowser_toke");
        }
        $table = new xmldb_table("block_lockdownbrowser_sessions");
        if ($dbman->table_exists($table)) {
            $dbman->rename_table($table, "block_lockdownbrowser_sess");
        }
        upgrade_block_savepoint(true, 2012082000, "lockdownbrowser");
    }
    if ($oldversion < 2013011800) {
        $table = new xmldb_table("block_lockdownbrowser");
        $index = new xmldb_index("course_ix");
        $index->set_attributes(XMLDB_INDEX_NOTUNIQUE, array("course"));
        if (!$dbman->index_exists($table, $index)) {
            $dbman->add_index($table, $index);
        }
        $table = new xmldb_table("block_lockdownbrowser_sett");
        $field = new xmldb_field("course", XMLDB_TYPE_INTEGER, "10", XMLDB_UNSIGNED, XMLDB_NOTNULL, null, 0, "id");
        if (!$dbman->field_exists($table, $field)) {
            $dbman->add_field($table, $field);
        }
        $field = new xmldb_field("monitor", XMLDB_TYPE_TEXT, "small", null, null, null, null, "password");
        if (!$dbman->field_exists($table, $field)) {
            $dbman-&