一、创建学生表
CREATE TABLE STUDENTS( STU_ID NUMBER(10) CONSTRAINTS PK_STUS_ID PRIMARY KEY, STU_NAME VARCHAR2(20) NOT NULL, STU_SCORES NUMBER(3) )
二、插入数据
INSERT INTO STUDENTS VALUES(001,'张三',56); INSERT INTO STUDENTS VALUES(002,'李四',98); INSERT INTO STUDENTS VALUES(003,'王五',40); INSERT INTO STUDENTS VALUES(004,'赵六张',60); INSERT INTO STUDENTS VALUES(005,'小翠',100);
三、查询数据
（一）查询所有数据
SELECT * FROM STUDENTS;
（二）查询出每个学员的姓名和考试成绩
SELECT STU_NAME,STU_SCORES FROM STUDENTS;
（三）查询出考试不及格的学生的信息
SELECT STU_ID,STU_NAME,STU_SCORES FROM STUDENTS WHERE STU_SCORES<60;
（四）查询姓名包含“张”的学生的信息(用模糊查询)
SELECT STU_ID,STU_NAME,STU_SCORES FROM STUDENTS WHERE STU_NAME LIKE '%张%';
（五）查询所有学生的信息并按学习成绩降序排序
SELECT STU_ID,STU_NAME,STU_SCORES FROM STUDENTS ORDER BY STU_SCORES DESC;
