第1章：初识MySQL ——课后作业：

#图书信息表

DESC `book`;
DROP TABLE IF EXISTS `book`;
CREATE TABLE `book`(
`bid`CHAR COMMENT'图书编号'PRIMARY KEY,
`bName`CHAR COMMENT'图书书名',
`author`CHAR COMMENT'作者姓名',
`pubComp`CHAR COMMENT'出版社',
`pubDate`DATETIME  COMMENT'出版日期',
`bCount`INT COMMENT'现存数量',
`price`FLOAT COMMENT'单价'
)

#图书借阅表

DESC `borrow`;
DROP TABLE IF EXISTS `borrow`;
CREATE TABLE `borrow`(
`rid`CHAR COMMENT'读者编号',
`nif`CHAR COMMENT'图书编号',
`lendDate`DATETIME DEFAULT NOW() COMMENT'借阅日期',
`willDate`DATETIME COMMENT'应归还日期',
`retunDate`DATETIME COMMENT'实际归还日期',
PRIMARY KEY(`rid`,`nif`,`lendDate`)
)

#读者信息表

DESC reader;
DROP TABLE IF EXISTS `reader`;
CREATE TABLE `reader`(
`rid`CHAR COMMENT'读者编号'PRIMARY key,
`rName`CHAR COMMENT'读者姓名',
`lendNum`INT COMMENT'已借书数量',
`rAddress`CHAR COMMENT'联系地址'
)

#罚款记录表

DESC `penalty`;
DROP TABLE IF EXISTS `penalty`;
CREATE TABLE `penalty`(
`rid`CHAR COMMENT'读者编号',
`bid`CHAR COMMENT'读书编号',
`pDate`DATETIME COMMENT'罚款日期',
`pType`INT COMMENT'罚款类型',
`amount`FLOAT COMMENT'罚款金额',
PRIMARY KEY(`rid`,`bid`,`pDate`)
)