statservice.java

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package com.bjsxt.shopping.stat;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.bjsxt.shopping.util.DB;

public class StatService {
	public static List<ProductStatItem> getProductsBySaleCount() {
		Connection conn = DB.getConn();
		Statement stmt = DB.getStatement(conn);
		ResultSet rs = null;
		List<ProductStatItem> list = new ArrayList<ProductStatItem>();
		try {

			String sql = "select productid, sum(pcount) totalsalescount, name from salesitem join " +
					     " product on (salesitem.productid = product.id) " +
					     " group by productid order by totalsalescount desc";
			rs = DB.getResultSet(stmt, sql);
			while (rs.next()) {
				ProductStatItem p = new ProductStatItem();
				p.setProductId(rs.getInt("productid"));
				p.setTotalSalesCount(rs.getInt("totalsalescount"));
				p.setProductName(rs.getString("name"));
				list.add(p);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			DB.close(stmt);
			DB.close(rs);
			DB.close(conn);
		}

		return list;
	}
}