经典电商数据库分析构建（二）
传统电商表的分析以及设计（java代码处理上文中的七个任务）2
工具类 JDBCUtils.java
/**
* @author 高远</n> 博客 http://blog.csdn.net/wgyscsf</n> 编写时期 2016-3-17 上午10:04:02
*/
public class JDBCUtils {
private static String url = "jdbc:mysql://localhost:3306/mygist";
private static String user = "root";
private static String password = "wanggaoyuan";
private static Connection conn;
static {
}
/*
* 装载驱动
*/
public static void loadDriver() {
try {
Class.forName("com.mysql.jdbc.Driver");// 高版本不需要该语句
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/*
* 获取连接
*/
public static Connection getConnection() {
loadDriver();
try {
conn = DriverManager.getConnection(url, user, password);
return conn;
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
/*
* 释放连接
*/
public static void releaseConn(Statement stmt, Connection conn) {
if (stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
stmt = null;
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
conn = null;
}
}
/*
* 释放连接
*/
public static void releaseConn(ResultSet rs, Statement stmt, Connection conn) {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
rs = null;
}
releaseConn(stmt, conn);
}
}
对上述文章的七个数据库操作语句的java实现 ShowMyGist.java
/**
* @author 高远</n> 博客 http://blog.csdn.net/wgyscsf</n> 编写时期 2016-3-17 上午10:58:11
*/
public class ShowMyGist {
/*
* 1. 从商品表中查询以“老板”两个字开头的商品名称及数量，并按数量降序排序（用户搜索）
*/
@Test
public void Test1() throws SQLException {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "SELECT pname 商品名,premain 剩余量 FROM product WHERE pname LIKE '老板%' ORDER BY premain";
conn = JDBCUtils.getConnection();
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
while (rs.next()) {
System.out.println(rs.getString(1) + ":" + rs.getInt(2));
}
JDBCUtils.releaseConn(rs, ps, conn);
}
/*
* 2. 查询所有的商品名、价格、所属厂家、产地）（商品信息展示）
*/
@Test
public void Test2() throws SQLException {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "SELECT pname 商品名,premain 剩余量,pprice 价格,mname 所属厂家,maddress 产地 FROM product,merchant WHERE product.mid = merchant.mid ";
conn = JDBCUtils.getConnection();
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
while (rs.next()) {
System.out
.println(rs.getString(1) + ":" + rs.getInt(2) + ":"
+ rs.getDouble(3) + rs.getString(4) + ":"
+ rs.getString(5));
}
JDBCUtils.releaseConn(rs, ps, conn);
}
/*
* 3. 从订单表中查询购买订单编号为“2”的所有商品的商品名字、单价、数量、顾客名字及订单日期（用户查看订单）
*/
@Test
public void Test3() throws SQLException {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "SELECT pname 商品名,premain 剩余量,pprice 价格,cname 顾客名,"
+ "odatetime 订单日期 FROM product,customer,orders,ordersitem WHERE"
+ " ordersitem.pid = product.pid AND ordersitem.oid = orders.oid "
+ "AND orders.cid = customer.cid AND orders.oid = ? ";
System.out.println("请输入您要查询的订单号：");
Scanner sc = new Scanner(System.in);
int next = sc.nextInt();
conn = JDBCUtils.getConnection();
ps = conn.prepareStatement(sql);
ps.setInt(1, next);
rs = ps.executeQuery();
if (!rs.next()) {
System.out.println("查询不到该订单！");
return;
}
while (rs.next()) {
System.out
.println(rs.getString(1) + ":" + rs.getInt(2) + ":"
+ rs.getDouble(3) + rs.getString(4) + ":"
+ rs.getString(5));
}
JDBCUtils.releaseConn(rs, ps, conn);
}
/*
* 4.
* 更新订单1：更新状态为“已支付”，总价格为实际价格。显示：订单编号为“1”的所有商品的商品名字、单价、数量、顾客名字及订单日期，总价格，订单状态
* （用户支付查看订单）
*/
@Test
public void Test4() throws SQLException {
Connection conn = null;
PreparedStatement ps = null;
String sql = "UPDATE orders SET orders.ostate = '已支付',"
+ "orders.osummoney =" + "(SELECT (SELECT SUM( "
+ " ordersitem.iobuynum * ordersitem.iosummoney )"
+ " FROM ordersitem WHERE ordersitem.oid = orders.oid "
+ " AND ordersitem.oid = ? GROUP BY ordersitem.oid)) "
+ "WHERE orders.oid =?";
System.out.println("请输入您要更新的订单号：");
Scanner sc = new Scanner(System.in);
int next = sc.nextInt();
conn = JDBCUtils.getConnection();
ps = conn.prepareStatement(sql);
ps.setInt(1, next);
ps.setInt(2, next);
ps.executeUpdate();
JDBCUtils.releaseConn(ps, conn);
}
/*
* 5. 删除订单3信息（用户取消订单）
*/
@Test
public void Test5() throws SQLException {
Connection conn = null;
PreparedStatement ps = null;
System.out.println("请输入您要删除的订单号：");
Scanner sc = new Scanner(System.in);
int next = sc.nextInt();
String sql1 = "DELETE FROM ordersitem WHERE oid=?";
String sql2 = "DELETE FROM orders WHERE oid=?";
conn = JDBCUtils.getConnection();
conn.setAutoCommit(false);// 开启事务：保证两个删除同时完成
ps = conn.prepareStatement(sql1);
ps.setInt(1, next);
ps.executeUpdate();
ps = conn.prepareStatement(sql2);
ps.setInt(1, next);
ps.executeUpdate();
conn.commit();// 提交事务
JDBCUtils.releaseConn(ps, conn);
Test3();
}
/*
* 6. 查询编号为2的商品的售出数量、名字、购买人名字（商家查看某件商品出售情况）
*/
@Test
public void Test6() throws SQLException {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "SELECT SUM(ordersitem.iobuynum) 售出数量,"
+ "SUM(ordersitem.iobuynum*product.pprice) 总价,"
+ "product.pname 商品名称,customer.cname 顾客名字 "
+ " FROM product,customer, orders, ordersitem "
+ "WHERE ordersitem.pid = product.pid AND"
+ " ordersitem.oid = orders.oid AND "
+ "orders.cid = customer.cid AND "
+ "product.pid = ? GROUP BY customer.cid";
System.out.println("请输入您要查询的商品的编号：");
Scanner sc = new Scanner(System.in);
int next = sc.nextInt();
conn = JDBCUtils.getConnection();
ps = conn.prepareStatement(sql);
ps.setInt(1, next);
rs = ps.executeQuery();
while (rs.next()) {
System.out.println("售出数量：" + rs.getInt(1) + "----" + "总销价："
+ rs.getDouble(2) + "----商品名字：" + rs.getString(3)
+ "-----顾客名字：" + rs.getString(4));
}
JDBCUtils.releaseConn(rs, ps, conn);
}
/*
* 7. 查看宝洁公司的销售情况,按照销售数量由高到低排序（商家查看售出数据）
*/
@Test
public void Test7() throws SQLException {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "SELECT SUM(ordersitem.iobuynum) 售出数量,"
+ "SUM( ordersitem.iobuynum * product.pprice) 总价"
+ ", product.pname 商品名字 FROM "
+ "product, ordersitem, merchant "
+ "WHERE ordersitem.pid = product.pid "
+ " AND product.mid = merchant.mid "
+ " AND merchant.mname = '广州宝洁' " + "GROUP BY product.pname ";
conn = JDBCUtils.getConnection();
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
while (rs.next()) {
System.out.println("售出数量：" + rs.getInt(1) + "----" + "总销价："
+ rs.getDouble(2) + "----商品名字：" + rs.getString(3));
}
JDBCUtils.releaseConn(rs, ps, conn);
}
/*
* 8. 将售出的商品按照售出数量由高到低排序（管理员查看售出数据）
*/
@Test
public void Test8() throws SQLException {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "SELECT SUM(ordersitem.iobuynum) 售出数量,"
+ "SUM( ordersitem.iobuynum * product.pprice) 总价"
+ ", product.pname 商品名字 FROM "
+ "product, ordersitem, merchant "
+ "WHERE ordersitem.pid = product.pid "
+ " AND product.mid = merchant.mid "
+ " GROUP BY product.pname ORDER BY ordersitem.iobuynum DESC ";
conn = JDBCUtils.getConnection();
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
while (rs.next()) {
System.out.println("售出数量：" + rs.getInt(1) + "----" + "总销价："
+ rs.getDouble(2) + "----商品名字：" + rs.getString(3));
}
JDBCUtils.releaseConn(rs, ps, conn);
}
}