简单sql句语整理资料.docxVIP

? 表操作?例1?对于表的教学管理数据库中的表STUDENTS，可以定义如下：?? CREATE?TABLE?STUDENTS?? (SNO????? NUMERIC (6, 0) NOT NULL?? SNAME??? CHAR (8) NOT NULL?? AGE????? NUMERIC(3,0)?? SEX????? CHAR(2)?? BPLACE?CHAR(20)?? PRIMARY KEY(SNO))例2?对于表的教学管理数据库中的表ENROLLS，可以定义如下：????? ??CREATE?TABLE?ENROLLS??????? (SNO????? NUMERIC(6,0)?NOT NULL??????? CNO???? CHAR(4)?NOT NULL??????? GRADE?? INT??????? PRIMARY KEY(SNO,CNO)??????? FOREIGN KEY(SNO) REFERENCES STUDENTS(SNO)??????? FOREIGN KEY(CNO) REFERENCES COURSES(CNO)??????? CHECK ((GRADE IS NULL) OR (GRADE BETWEEN 0 AND 100)))例 3?根据表的 STUDENTS 表，建立一个只包含学号、姓名、年龄的女学生表。??????? CREATE TABLE GIRL??????? AS SELECT SNO, SNAME, AGE ??????? FROM STUDENTS??????? WHERE SEX=女;?例4?删除教师表TEACHER。??????? DROP?TABLE?TEACHER例5?在教师表中增加住址列。?????? ALTER TABLE TEACHERS?????? ADD (ADDR CHAR(50))例6?把STUDENTS表中的BPLACE列删除，并且把引用BPLACE列的所有视图和约束也一起删除。??????? ALTER TABLE STUDENTS??????? DROP BPLACE CASCADE例7?补充定义ENROLLS表的主关键字。????? ?ALTER TABLE ENROLLS?????? ADD PRIMARY KEY (SNO,CNO)；?视图操作（虚表）?例9?建立一个只包括教师号、姓名和年龄的视图FACULTY。(在视图定义中不能包含ORDER BY子句)??????? CREATE VIEW FACULTY??????? AS SELECT TNO, TNAME, AGE??????? FROM TEACHERS例10?从学生表、课程表和选课表中产生一个视图GRADE_TABLE，它包括学生姓名、课程名和成绩。??????? CREATE VIEW GRADE_TABLE ??????? AS SELECT?SNAME,CNAME,GRADE??????? FROM?STUDENTS,COURSES,ENROLLS??????? WHERE?STUDENTS.SNO＝ENROLLS.SNO AND??????? COURSES.CNO=ENROLLS.CNO例11?删除视图GRADE_TABLE??????? DROP VIEW GRADE_TABLE RESTRICT?索引操作?例12?在学生表中按学号建立索引。??????? CREATE ?UNIQUE ?INDEX ?ST??????? ON STUDENTS (SNO,ASC)例13?删除按学号所建立的索引。??????? DROP INDEX ST?数据库模式操作?例14?创建一个简易教学数据库的数据库模式?TEACHING_DB，属主为ZHANG。??????? CREATE SCHEMA TEACHING_DB ?AUTHRIZATION ?ZHANG例15?删除简易教学数据库模式TEACHING_DB。（（1）选用CASCADE，即当删除数据库模式时，则本数据库模式和其下属的基本表、视图、索引等全部被删除。（2）选用RESTRICT，即本数据库模式下属的基本表、视图、索引等事先已清除，才能删除本数据库模式，否则拒绝删除。）??????? DROP SCHEMA TEACHING_DB CASCADE单表操作?例16?找出3个学分的课程号和课程名。???????? SELECT CNO, CNAME???????? FROM 　COURSES???????? WHERE　CREDIT＝3例17?查询年龄大于22岁的学生情况。???????? SELECT?*???????? FROM?? STUDENTS???????? WHERE?AGE＞22例18?? 找出籍