1、在fruits表和suppliers表之间使用等值连接查询。( s_id ,s_name,f_name, f_price ) , 2、在fruits表和suppliers表之间,使用INNER JOIN语法进行内连接查询( s_id ,s_name,f_name, f_price ) , SELECT suppliers.s_id, s_name,f_name, f_price FROM fruits INNER JOIN suppliers ON fruits.s_id = suppliers.s_id;
3、.LEFT JOIN左连接 首先创建表orders,SQL语句如下: CREATE TABLE orders
(
o_num number(9) NOT NULL,
o_date date NOT NULL,
c_id number(9) NOT NULL,
PRIMARY KEY (o_num)
) ;
插入需要演示的数据,SQL语句如下: INSERT INTO orders(o_num, o_date, c_id)VALUES(30001, '01-9月-2008', 10001);
INSERT INTO orders(o_num, o_date, c_id)VALUES (30002, '12-9月-2008', 10003) ;
INSERT INTO orders(o_num, o_date, c_id)VALUES (30003, '30-9月-2008', 10004) ;
INSERT INTO orders(o_num, o_date, c_id)VALUES (30004, '03-10月-2008', 10005) ;
INSERT INTO orders(o_num, o_date, c_id)VALUES (30005, '08-10月-2008', 10001) ;
在customers表和orders表中,查询所有客户,包括没有订单的客户 4、RIGHT JOIN右连接 在customers表和orders表中,查询所有订单,包括没有客户的订单 5、复合条件连接查询 在customers表和orders表中,使用INNER JOIN语法查询customers表中ID为10001的客户的订单信息 - SELECT customers.c_id, orders.o_num FROM customers INNER JOIN orders ON customers.c_id = orders.c_id AND customers.c_id = 10001;
6、在fruits表和suppliers表之间,使用INNER JOIN语法进行内连接查询,并对查询结果排序 - > SELECT suppliers.s_id, s_name,f_name, f_price FROM fruits INNER JOIN suppliers ON fruits.s_id = suppliers.s_id
7、下面定义两个表tb1和tb2: CREATE table tbl1 ( num1 INT NOT NULL);
CREATE table tbl2 ( num2 INT NOT NULL);
分别向两个表中插入数据: I INSERT INTO tbl1 values(1);
INSERT INTO tbl1 values(5);
INSERT INTO tbl1 values(13);
INSERT INTO tbl1 values(27);
INSERT INTO tbl2 values(6);
INSERT INTO tbl2 values(14);
INSERT INTO tbl2 values(11);
INSERT INTO tbl2 values(20);
8、返回tbl2表的所有num2列,然后将tbl1中的num1的值与之进行比较,只要大于num2的任何1个值,即为符合查询条件的结果。 9、返回tbl1表中比tbl2表num2 列所有值都大的值 10、在orderitems表中查询f_id为c0的订单号,并根据订单号查询具有订单号的客户c_id 11、在suppliers表中查询s_city等于“Tianjin”的供应商s_id,然后在fruits表中查询所有该供应商提供的水果的种类 12、查询所有价格小于9的水果的信息,查询s_id等于101和103所有的水果的信息,使用UNION连接查询结果 13、查询所有价格小于9的水果的信息,查询s_id等于101和103的所有水果的信息,使用UNION ALL连接查询结果 create table student(
sno varchar2(10) primary key,
sname varchar2(20),
sage number(2),
ssex varchar2(5)
);
create table teacher(
tno varchar2(10) primary key,
tname varchar2(20)
);
create table course(
cno varchar2(10),
cname varchar2(20),
tno varchar2(20),
constraint pk_course primary key (cno,tno)
);
create table sc(
sno varchar2(10),
cno varchar2(10),
score number(4,2),
constraint pk_sc primary key (sno,cno)
);
/*******初始化学生表的数据******/
insert into student values ('s001','张三',23,'男');
insert into student values ('s002','李四',23,'男');
insert into student values ('s003','吴鹏',25,'男');
insert into student values ('s004','琴沁',20,'女');
insert into student values ('s005','王丽',20,'女');
insert into student values ('s006','李波',21,'男');
insert into student values ('s007','刘玉',21,'男');
insert into student values ('s008','萧蓉',21,'女');
insert into student values ('s009','陈萧晓',23,'女');
insert into student values ('s010','陈美',22,'女');
commit;
/******************初始化教师表***********************/
insert into teacher values ('t001', '刘阳');
insert into teacher values ('t002', '谌燕');
insert into teacher values ('t003', '胡明星');
commit;
/***************初始化课程表****************************/
insert into course values ('c001','J2SE','t002');
insert into course values ('c002','Java Web','t002');
insert into course values ('c003','SSH','t001');
insert into course values ('c004','Oracle','t001');
insert into course values ('c005','SQL SERVER 2005','t003');
insert into course values ('c006','C#','t003');
insert into course values ('c007','JavaScript','t002');
insert into course values ('c008','DIV+CSS','t001');
insert into course values ('c009','PHP','t003');
insert into course values ('c010','EJB3.0','t002');
commit;
/***************初始化成绩表***********************/
insert into sc values ('s001','c001',78.9);
insert into sc values ('s002','c001',80.9);
insert into sc values ('s003','c001',81.9);
insert into sc values ('s004','c001',60.9);
insert into sc values ('s001','c002',82.9);
insert into sc values ('s002','c002',72.9);
insert into sc values ('s003','c002',81.9);
insert into sc values ('s001','c003','59');
commit;
14、查询“c001”课程比“c002”课程成绩高的所有学生的学号; 15、查询平均成绩大于60 分的同学的学号和平均成绩; 16、查询所有同学的学号、姓名、选课数、总成绩; 17、查询姓“刘”的老师的个数 18、查询没学过“谌燕”老师课的同学的学号、姓名; |