diff --git a/src/main/java/com/github/hcsp/sql/Sql.java b/src/main/java/com/github/hcsp/sql/Sql.java index 418a0df..ba7e99b 100644 --- a/src/main/java/com/github/hcsp/sql/Sql.java +++ b/src/main/java/com/github/hcsp/sql/Sql.java @@ -1,10 +1,13 @@ package com.github.hcsp.sql; +import com.sun.java.browser.plugin2.liveconnect.v1.Result; +import com.sun.org.apache.xpath.internal.operations.Or; +import org.h2.jdbcx.JdbcDataSource; + import java.io.File; import java.math.BigDecimal; -import java.sql.Connection; -import java.sql.DriverManager; -import java.sql.SQLException; +import java.sql.*; +import java.util.ArrayList; import java.util.List; public class Sql { @@ -62,6 +65,13 @@ public static class User { String tel; String address; + public User(Integer id, String name, String tel, String address) { + this.id = id; + this.name = name; + this.tel = tel; + this.address = address; + } + @Override public String toString() { return "User{" + "id=" + id + ", name='" + name + '\'' + ", tel='" + tel + '\'' + ", address='" + address + '\'' + '}'; @@ -82,7 +92,20 @@ public String toString() { // | 2 | // +-----+ public static int countUsersWhoHaveBoughtGoods(Connection databaseConnection, Integer goodsId) throws SQLException { - return 0; + + String sql = "SELECT COUNT(distinct USER_ID) FROM `ORDER` where GOODS_ID =?"; + + try (PreparedStatement statement = databaseConnection.prepareStatement(sql)) { + //给第一个预编译的参数 传入 goodsId + statement.setInt(1, goodsId); + //获取查询结果集 + ResultSet resultSet = statement.executeQuery(); + if (resultSet.next()) { + //获取第一列的数据返回 + return resultSet.getInt(1); + } + } + return -1; } /** @@ -100,7 +123,23 @@ public static int countUsersWhoHaveBoughtGoods(Connection databaseConnection, In // | 1 | zhangsan | tel1 | beijing | // +----+----------+------+----------+ public static List getUsersByPageOrderedByIdDesc(Connection databaseConnection, int pageNum, int pageSize) throws SQLException { - return null; + List users = new ArrayList<>(); + + String sql = "select * from user order by id desc limit ? offset ?"; + try(PreparedStatement statement = databaseConnection.prepareStatement(sql)) { + statement.setInt(1,pageNum); + statement.setInt(2,pageSize); + + ResultSet resultSet = statement.executeQuery(); + while (resultSet.next()) { + Integer id = resultSet.getInt(1); + String name = resultSet.getString(2); + String tel = resultSet.getString(3); + String address = resultSet.getString(4); + users.add(new User(id,name,tel,address)); + } + } + return users; } // 商品及其营收 @@ -109,6 +148,12 @@ public static class GoodsAndGmv { String goodsName; // 商品名 BigDecimal gmv; // 商品的所有销售额 + public GoodsAndGmv(Integer goodsId, String goodsName, BigDecimal gmv) { + this.goodsId = goodsId; + this.goodsName = goodsName; + this.gmv = gmv; + } + @Override public String toString() { return "GoodsAndGmv{" + "goodsId=" + goodsId + ", goodsName='" + goodsName + '\'' + ", gmv=" + gmv + '}'; @@ -132,7 +177,22 @@ public String toString() { // | 3 | goods3 | 20 | // +----+--------+------+ public static List getGoodsAndGmv(Connection databaseConnection) throws SQLException { - return null; + List result = new ArrayList<>(); + String sql = "select GOODS_ID,GOODS.NAME as NAME, SUM(GOODS_PRICE*GOODS_NUM) as GMV\n" + + "from \"ORDER\" join GOODS on \"ORDER\".GOODS_ID= GOODS.ID\n" + + "group by GOODS_ID order by GMV desc"; + try (PreparedStatement statement = databaseConnection.prepareStatement(sql)) { + ResultSet resultSet = statement.executeQuery(); + while (resultSet.next()) { + GoodsAndGmv temp = new GoodsAndGmv( + resultSet.getInt(1), + resultSet.getString(2), + resultSet.getBigDecimal(3) + ); + result.add(temp); + } + } + return result; } @@ -170,7 +230,19 @@ public String toString() { // | 6 | zhangsan | goods3 | 20 | // +----------+-----------+------------+-------------+ public static List getInnerJoinOrders(Connection databaseConnection) throws SQLException { - return null; + List orders; + ResultSet resultSet; + String sql = "SELECT \"ORDER\".USER_ID, USER.NAME AS USER_NAME, GOODS.NAME AS GOODS_NAME, \"ORDER\".GOODS_NUM * \"ORDER\".GOODS_PRICE AS TOTAL_PRICE\n" + + "FROM \"ORDER\"\n" + + "JOIN USER ON \"ORDER\".USER_ID = USER.ID\n" + + "JOIN GOODS ON \"ORDER\".GOODS_ID = GOODS.ID"; + + try (PreparedStatement statement = databaseConnection.prepareStatement(sql)) { + //获取结果集 + resultSet = statement.executeQuery(); + orders = fillingOrderList(resultSet); + } + return orders; } /** @@ -198,9 +270,45 @@ public static List getInnerJoinOrders(Connection databaseConnection) thro // | 8 | NULL | NULL | 60 | // +----------+-----------+------------+-------------+ public static List getLeftJoinOrders(Connection databaseConnection) throws SQLException { - return null; + List orders; + String sql = "SELECT \"ORDER\".USER_ID, USER.NAME AS USER_NAME, GOODS.NAME AS GOODS_NAME, \"ORDER\".GOODS_NUM * \"ORDER\".GOODS_PRICE AS TOTAL_PRICE\n" + + "FROM \"ORDER\"\n" + + "LEFT JOIN USER ON \"ORDER\".USER_ID = USER.ID\n" + + "LEFT JOIN GOODS ON \"ORDER\".GOODS_ID = GOODS.ID"; + ResultSet resultSet; + try (PreparedStatement statement = databaseConnection.prepareStatement(sql)) { + //获取结果集 + resultSet = statement.executeQuery(); + orders = fillingOrderList(resultSet); + } + return orders; } + public static List fillingOrderList(ResultSet resultSet) { + List orderList = new ArrayList<>(); + while (true) { + try { + if (!resultSet.next()) break; + Integer id = resultSet.getInt(1); + String user_name = resultSet.getString(2); + String goods_name = resultSet.getString(3); + BigDecimal price = resultSet.getBigDecimal(4); + + Order order = new Order(); + order.id = id; + order.userName = user_name; + order.goodsName = goods_name; + order.totalPrice = price; + + orderList.add(order); + } catch (SQLException throwables) { + throwables.printStackTrace(); + } + + } + + return orderList; + } // 注意，运行这个方法之前，请先运行mvn initialize把测试数据灌入数据库 public static void main(String[] args) throws SQLException { File projectDir = new File(System.getProperty("basedir", System.getProperty("user.dir")));