1.创建表 t_reader
CREATE TABLE t_reader (
  reader_id CHAR(6) ,
  reader_name VARCHAR(50) ,
  reader_sex CHAR(2) ,
  reader_birthday DATE ,
  reader_borrowtotal FLOAT 
) ;
2.查看t_reader表结构
DESCRIBE t_reader;
3.查看数据库下的所有表
SHOW TABLES;
4.创建表t_book
CREATE TABLE t_book (
  ISBN CHAR(17) ,
  book_name VARCHAR(50) ,
  book_author VARCHAR(50) ,
  book_price DECIMAL(6,1) ,
  press_id CHAR(3) 
) ;
5.创建表t_press 
CREATE TABLE t_press (
  press_id CHAR(3) ,
  press_name VARCHAR(50) ,
  website VARCHAR(50) ,
  press_telephone VARCHAR(20) ,
  press_email VARCHAR(50) ,
  press_address VARCHAR(100) ,
  postcode CHAR(6) 
) ;
6.创建表t_borrow_record
CREATE TABLE t_borrow_record (
  borrow_id CHAR(6) ,
  reader_id CHAR(6) ,
  ISBN CHAR(17) ,
  borrow_date DATE 
) ;
7..创建表t_return_record
CREATE TABLE t_return_record (
  return_id CHAR(9) ,
  borrow_id CHAR(6) ,
  return_date DATE,
  ISBN CHAR(17),
  borrow_date DATE 
) ;
8.创建一个和t_book相同的表结构t_book1
create table t_book1 like t_book;
