phpbb\convert\convertor::build_insert_query PHP Method

    function build_insert_query(&$schema, &$sql_data, $current_table)
    {
        global $db, $user;
        global $convert;
        // Can we use IGNORE with this DBMS?
        $sql_ignore = strpos($db->get_sql_layer(), 'mysql') === 0 && !defined('DEBUG') ? 'IGNORE ' : '';
        $insert_query = 'INSERT ' . $sql_ignore . 'INTO ' . $schema['target'] . ' (';
        $aliases = array();
        $sql_data = array('source_fields' => array(), 'target_fields' => array(), 'source_tables' => array(), 'select_fields' => array());
        foreach ($schema as $key => $val) {
            // Example: array('group_name',				'extension_groups.group_name',		'htmlspecialchars'),
            if (is_int($key)) {
                if (!empty($val[0])) {
                    // Target fields
                    $sql_data['target_fields'][$val[0]] = $key;
                    $insert_query .= $val[0] . ', ';
                }
                if (!is_array($val[1])) {
                    $val[1] = array($val[1]);
                }
                foreach ($val[1] as $valkey => $value_1) {
                    // This should cover about any case:
                    //
                    // table.field					=> SELECT table.field				FROM table
                    // table.field AS alias			=> SELECT table.field	AS alias	FROM table
                    // table.field AS table2.alias	=> SELECT table2.field	AS alias	FROM table table2
                    // table.field AS table2.field	=> SELECT table2.field				FROM table table2
                    //
                    if (preg_match('/^([a-z0-9_]+)\\.([a-z0-9_]+)( +AS +(([a-z0-9_]+?)\\.)?([a-z0-9_]+))?$/i', $value_1, $m)) {
                        // There is 'AS ...' in the field names
                        if (!empty($m[3])) {
                            $value_1 = $m[2] == $m[6] ? $m[1] . '.' . $m[2] : $m[1] . '.' . $m[2] . ' AS ' . $m[6];
                            // Table alias: store it then replace the source table with it
                            if (!empty($m[5]) && $m[5] != $m[1]) {
                                $aliases[$m[5]] = $m[1];
                                $value_1 = str_replace($m[1] . '.' . $m[2], $m[5] . '.' . $m[2], $value_1);
                            }
                        } else {
                            // No table alias
                            $sql_data['source_tables'][$m[1]] = empty($convert->src_table_prefix) ? $m[1] : $convert->src_table_prefix . $m[1] . ' ' . $m[1];
                        }
                        $sql_data['select_fields'][$value_1] = $value_1;
                        $sql_data['source_fields'][$key][$valkey] = !empty($m[6]) ? $m[6] : $m[2];
                    }
                }
            } else {
                if ($key == 'where' || $key == 'group_by' || $key == 'order_by' || $key == 'having') {
                    if (@preg_match_all('/([a-z0-9_]+)\\.([a-z0-9_]+)/i', $val, $m)) {
                        foreach ($m[1] as $value) {
                            $sql_data['source_tables'][$value] = empty($convert->src_table_prefix) ? $value : $convert->src_table_prefix . $value . ' ' . $value;
                        }
                    }
                }
            }
        }
        // Add the aliases to the list of tables
        foreach ($aliases as $alias => $table) {
            $sql_data['source_tables'][$alias] = $convert->src_table_prefix . $table . ' ' . $alias;
        }
        // 'left_join'		=> 'forums LEFT JOIN forum_prune ON forums.forum_id = forum_prune.forum_id',
        if (!empty($schema['left_join'])) {
            if (!is_array($schema['left_join'])) {
                $schema['left_join'] = array($schema['left_join']);
            }
            foreach ($schema['left_join'] as $left_join) {
                // This won't handle concatened LEFT JOINs
                if (!preg_match('/([a-z0-9_]+) LEFT JOIN ([a-z0-9_]+) A?S? ?([a-z0-9_]*?) ?(ON|USING)(.*)/i', $left_join, $m)) {
                    $this->error(sprintf($user->lang['NOT_UNDERSTAND'], 'LEFT JOIN', $left_join, $current_table, $schema['target']), __LINE__, __FILE__);
                }
                if (!empty($aliases[$m[2]])) {
                    if (!empty($m[3])) {
                        $this->error(sprintf($user->lang['NAMING_CONFLICT'], $m[2], $m[3], $schema['left_join']), __LINE__, __FILE__);
                    }
                    $m[2] = $aliases[$m[2]];
                    $m[3] = $m[2];
                }
                $right_table = $convert->src_table_prefix . $m[2];
                if (!empty($m[3])) {
                    unset($sql_data['source_tables'][$m[3]]);
                } else {
                    if ($m[2] != $m[1]) {
                        unset($sql_data['source_tables'][$m[2]]);
                    }
                }
                if (strpos($sql_data['source_tables'][$m[1]], "\nLEFT JOIN") !== false) {
                    $sql_data['source_tables'][$m[1]] = '(' . $sql_data['source_tables'][$m[1]] . ")\nLEFT JOIN {$right_table}";
                } else {
                    $sql_data['source_tables'][$m[1]] .= "\nLEFT JOIN {$right_table}";
                }
                if (!empty($m[3])) {
                    unset($sql_data['source_tables'][$m[3]]);
                    $sql_data['source_tables'][$m[1]] .= ' AS ' . $m[3];
                } else {
                    if (!empty($convert->src_table_prefix)) {
                        $sql_data['source_tables'][$m[1]] .= ' AS ' . $m[2];
                    }
                }
                $sql_data['source_tables'][$m[1]] .= ' ' . $m[4] . $m[5];
            }
        }
        // Remove ", " from the end of the insert query
        $insert_query = substr($insert_query, 0, -2) . ') VALUES ';
        return $insert_query;
    }