graded number(10)PRIMARY KEY gradename varchar 2 (20)UNIQUE NOT NULL) TABLESPACE book oracle: 5)创建管理员表( manager) SQL语句 CREATE TABLE manager( managerid number(10) PRIMARY KEY ealname varchar 2(10)NOT NULI sex char(2)NOT NULL username varchar 2 (16 NOT NULL password varchar 2 (16) NOT NULL, registertime DATE NOT NULL graded number(10)DEFAULT 1 NOT NULL, CONSTRAINT manager_ grade FOREIGN KEY(graded)REFERENCES grade(gradeid TAbleSPace book oracl 6)创建图书证表(card) SQL语句 CREATE TABLE card( cardid number(10 )PRIMARY KEY cardnumber char(9) UNIQUE NOT NULL studentid number(10) UNIQUE NOT NULL, registertime DAtE NoT nUll CONSTRAINT card student FOREIGN KEY(studentid) REFERENCES student(studentid) TableSPace book oracle 7)创建借书信息表(|end) SQL语句 CREATE TABLE lend( lendid number(10)PRIMARY KEYgradeid number(10) PRIMARY KEY , gradename varchar2(20) UNIQUE NOT NULL) TABLESPACE book_oracle; 5） 创建管理员表（manager） SQL 语句： CREATE TABLE manager ( managerid number(10) PRIMARY KEY , realname varchar2(10) NOT NULL, sex char(2) NOT NULL, username varchar2(16) NOT NULL, password varchar2(16) NOT NULL, registertime DATE NOT NULL, gradeid number(10) DEFAULT 1 NOT NULL, CONSTRAINT manager_grade FOREIGN KEY(gradeid) REFERENCES grade(gradeid) ) TABLESPACE book_oracle; 6） 创建图书证表（card） SQL 语句： CREATE TABLE card( cardid number(10) PRIMARY KEY , cardnumber char(9) UNIQUE NOT NULL, studentid number(10) UNIQUE NOT NULL, registertime DATE NOT NULL, CONSTRAINT card_student FOREIGN KEY(studentid) REFERENCES student(studentid) ) TABLESPACE book_oracle; 7） 创建借书信息表（lend） SQL 语句： CREATE TABLE lend( lendid number(10) PRIMARY KEY