数据库作业:
1.1 查询所有用户的订单
SELECT username,address,phone,oid,totalprice
FROM USER
INNER JOIN orders
ON user.`userId`=orders.`userId`;
查询结果:
1.2 查询用户id为 1 的所有订单详情
SELECT username,address,phone,orderitem.oid,cname,NAME,price,num,totalprice
FROM USER
INNER JOIN orders
ON user.`userId`=orders.`userId`
INNER JOIN orderitem
ON orders.`oid`=orderitem.`oid`
INNER JOIN products
ON orderitem.`pid`=products.`pid`
INNER JOIN category
ON products.`category_id`=category.`cid`
WHERE user.`userId`=1;
2.1查看用户为张三的订单
SELECT orders.`oid`,totalprice
FROM orders
WHERE userid =(SELECT userid FROM USER WHERE username='张三');
查询结果:
2.2查询出订单的价格大于800的所有用户信息
SELECT username,PASSWORD,address,phone
FROM USER
WHERE userid IN (SELECT userid FROM orders WHERE totalprice>800);
查询结果:
3.1查询所有订单信息,每页显示5条数据
SELECT username,address,phone,oid,totalprice
FROM USER
INNER JOIN orders
ON user.`userId`=orders.`userId`
LIMIT 0,5;
查询结果:
JDBC核心六步(增删改)
public class TestJDBC {
public static void main(String[] args) throws Exception{
/**
* 用户表
*/
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/hy3_28?useUnicode=true&characterEncoding=utf8";
String user = "root";
String password = "1234";
Connection connection = DriverManager.getConnection(url,user,password);
Statement statement = connection.createStatement();
System.out.println("进行新增操作");
String sql = "insert into user(username,password,address,phone)values('侯5',12345,'山西','13000001111')";
int insResult = statement.executeUpdate(sql);
dispose(insResult);
System.out.println("进行修改操作");
String sql1 = "update user set username='侯哈哈' where userid = 1";
int updResult = statement.executeUpdate(sql1);
dispose(updResult);
System.out.println("进行删除操作");
String sql2 = "delete from user where userid = 5";
int delResult = statement.executeUpdate(sql2);
dispose(delResult);
statement.close();
connection.close();
}
public static void dispose(int result){
if(result > 0){
System.out.println("修改成功");
}else{
System.out.println("修改失败");
}
}
}
public class TestJDBC {
public static void main(String[] args) throws Exception{
/**
* 分类表
*/
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/hy3_28?useUnicode=true&characterEncoding=utf8";
String user = "root";
String password = "1234";
Connection connection = DriverManager.getConnection(url,user,password);
Statement statement = connection.createStatement();
System.out.println("进行新增操作");
String sql = "insert into category(cid,cname)values('c006','零食')";
int insResult = statement.executeUpdate(sql);
dispose(insResult);
System.out.println("进行修改操作");
String sql1 = "update category set cname='食品' where cid='coo4'";
int updResult = statement.executeUpdate(sql1);
dispose(updResult);
System.out.println("进行删除操作");
String sql2 = "delete from category where cid='c005'";
int delResult = statement.executeUpdate(sql2);
dispose(delResult);
statement.close();
connection.close();
}
public static void dispose(int result){
if(result > 0){
System.out.println("修改成功");
}else{
System.out.println("修改失败");
}
}
}
public class TestJDBC {
public static void main(String[] args) throws Exception{
/**
* 商品表
*/
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/hy3_28?useUnicode=true&characterEncoding=utf8";
String user = "root";
String password = "1234";
Connection connection = DriverManager.getConnection(url,user,password);
Statement statement = connection.createStatement();
System.out.println("进行新增操作");
String sql = "insert into products(pid,NAME,price,category_id) VALUES('p012','香蕉',3000,'c007')";
int insResult = statement.executeUpdate(sql);
dispose(insResult);
System.out.println("进行修改操作");
String sql1 = "update products set name='耐克' where pid='p007'";
int updResult = statement.executeUpdate(sql1);
dispose(updResult);
System.out.println("进行删除操作");
String sql2 = "delete from products where pid='p010'";
int delResult = statement.executeUpdate(sql2);
dispose(delResult);
statement.close();
connection.close();
}
public static void dispose(int result){
if(result > 0){
System.out.println("修改成功");
}else{
System.out.println("修改失败");
}
}
}
public class TestJDBC {
public static void main(String[] args) throws Exception{
/**
* 订单表
*/
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/hy3_28?useUnicode=true&characterEncoding=utf8";
String user = "root";
String password = "1234";
Connection connection = DriverManager.getConnection(url,user,password);
Statement statement = connection.createStatement();
System.out.println("进行新增操作");
String sql = "insert into orders(oid,totalprice,userid) VALUES('o6104',3000.20,4)";
int insResult = statement.executeUpdate(sql);
dispose(insResult);
System.out.println("进行修改操作");
String sql1 = "update orders set userid = 3 where oid='o6101'";
int updResult = statement.executeUpdate(sql1);
dispose(updResult);
System.out.println("进行删除操作");
String sql2 = "delete from orders where oid='o6103'";
int delResult = statement.executeUpdate(sql2);
dispose(delResult);
statement.close();
connection.close();
}
public static void dispose(int result){
if(result > 0){
System.out.println("修改成功");
}else{
System.out.println("修改失败");
}
}
}
public class TestJDBC {
public static void main(String[] args) throws Exception{
/**
* 订单详表
*/
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/hy3_28?useUnicode=true&characterEncoding=utf8";
String user = "root";
String password = "1234";
Connection connection = DriverManager.getConnection(url,user,password);
Statement statement = connection.createStatement();
System.out.println("进行新增操作");
String sql = "insert into orderitem(oid,pid,num) VALUES('o6104','p007',2)";
int insResult = statement.executeUpdate(sql);
dispose(insResult);
System.out.println("进行修改操作");
String sql1 = "update orderitem set oid ='o6104' where pid='p002'";
int updResult = statement.executeUpdate(sql1);
dispose(updResult);
System.out.println("进行删除操作");
String sql2 = "delete from orderitem where pid='p003'";
int delResult = statement.executeUpdate(sql2);
dispose(delResult);
statement.close();
connection.close();
}
public static void dispose(int result){
if(result > 0){
System.out.println("修改成功");
}else{
System.out.println("修改失败");
}
}
}