我正在构建一个Java微服务，它使用AWS Aurora MySQL进行某些操作。代码连接到数据库很好，我的前三个查询都抛出了类似的错误，直到我意识到我丢失了数据库。
然而，最后一个查询（update语句）仍然给我同样的语法错误，即使是使用了codeon，我也不知道为什么。
代码如下：

try {
            conn = DriverManager.getConnection(jdbcUrl);
            setupStatement = conn.createStatement();
            idInsertStatement = conn.createStatement();
            secretNumberUpdateStatement = conn.createStatement();
            String createTableIfNotExists = "CREATE TABLE IF NOT EXISTS secret_number_generator(id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY, secret_number VARCHAR(20);";
            String generateSecretId = "INSERT INTO secret_number_generator VALUES(null,null);";
            String getLastRecordId = "SELECT id FROM secret_number_generator ORDER BY id DESC LIMIT 1;";
            setupStatement.addBatch(createTableIfNotExists);
            idInsertStatement.addBatch(generateSecretId);
            setupStatement.executeBatch();
            idInsertStatement.executeBatch();
            readStatement = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
            resultSet = readStatement.executeQuery(getLastRecordId);
            while(resultSet.next()){
                id = String.valueOf(resultSet.getLong("id"));
            }
            /*
              Logic for setting up secretNumber
            */
            }
            secretNumber = "R" + env + id + randomDigit;
            String updateSecretNumber = "UPDATE secret_number_generator SET secret_number = " + secretNumber + " WHERE id = " + id + ";";
            secretNumberUpdateStatement.addBatch(updateSecretNumber);
            secretNumberUpdateStatement.executeBatch();
            resultSet.close();
            setupStatement.close();
            idInsertStatement.close();
            secretNumberUpdateStatement.close();
            readStatement.close();
            conn.close();
        } catch (SQLException ex) {
            // Handle any errors
            System.out.println("SQLException: " + ex.getMessage());
            System.out.println("SQLState: " + ex.getSQLState());
            System.out.println("VendorError: " + ex.getErrorCode());
        } finally {
            System.out.println("Closing the connection.");
            if (conn != null) try { conn.close(); } catch (SQLException ignore) {}
        }

字符串
我得到的更新查询的错误是

SQLException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1

型
如前所述，在我在前面的查询末尾添加一个查询之前，它们也会显示相同的错误，现在它只显示在最后一个查询中。