text: SHOW DATABASES;
  USE honuxdb;
  DROP TABLE IF EXISTS USER;
  CREATE TABLE USER (
      ID VARCHAR(32),
      NAME VARCHAR(32) NOT NULL,
      PRIMARY KEY(ID)
  );
  
  DESC USER;
  
  INSERT INTO USER VALUES ('apple', 'honux'),('banana','crong'),('carrot','pobi');
  
  SELECT * FROM USER;
  
  DROP TABLE IF EXISTS BOARD;
  CREATE TABLE BOARD(
      ID INT NOT NULL AUTO_INCREMENT,
      DATE DATE,
      UID VARCHAR(32),
      TITLE VARCHAR(64) NOT NULL,
      PRIMARY KEY(ID));
  
  DESC BOARD;
  
  INSERT INTO BOARD (DATE, UID, TITLE) VALUES 
      ('2015-1-1','apple', 'hello'), 
      ('2015-1-2','banana', 'hi'), 
      ('2015-1-3','apple', 'good'), 
      ('2015-1-4','banana', 'zizi'), 
      ('2015-1-3',NULL, 'I am hacker');
  
  SELECT * FROM USER;
  SELECT * FROM BOARD; 
  
  SELECT U.ID AS USER_ID, NAME, 
      B.ID AS BOARD_ID, DATE, TITLE
      FROM USER U JOIN BOARD B 
      ON U.ID = B.UID;
  