java/FlowerDaoImpl.java

package flowershop.daoimpl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import flowershop.dao.FlowerDao;
import flowershop.model.Flower;

public class FlowerDaoImpl implements FlowerDao {

    //查询所有
    @Override
    public List<Flower> findAll() {
        // TODO 自动生成的方法存根
        String sql = "select productid,name,category,image,price,descn from flower";

        List<Flower> list = new ArrayList<Flower>();

        try (// 2.创建数据库连接
                Connection conn = Jdbc.getConnection();
                // 3.创建语句对象
                PreparedStatement pstmt = conn.prepareStatement(sql);
                // 4.绑定参数
                // 5.执行查询
                ResultSet rs = pstmt.executeQuery(sql)) {

            // 6.遍历结果集
            while (rs.next()) {

                Flower f = new Flower();

                f.setProductid(rs.getString("productid"));
                f.setName(rs.getString("name"));
                f.setCategory(rs.getString("category"));
                f.setImage(rs.getString("image"));
                f.setPrice(rs.getDouble("price"));
                f.setDescn(rs.getString("descn"));

                list.add(f);

            }
        } catch (SQLException e) {
            // TODO 自动生成的 catch 块
            e.printStackTrace();
        }

        return list;

    }

    //按主键查询用户
    @Override
    public Flower findById(String productid) {
        // TODO 自动生成的方法存根
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;

        String sql = "select productid,name,category,image,price,descn from flower where productid=?";

        try {
            // 2.创建数据库连接
            conn = Jdbc.getConnection();// 1.加载驱动程序
            // 3.创建语句对象
            pstmt = conn.prepareStatement(sql);
            // 4.绑定参数
            pstmt.setString(1, productid);
            // 5.执行查询
            rs = pstmt.executeQuery();
            // 6.遍历按主键查询
            if (rs.next()) {

                Flower f = new Flower();

                f.setProductid(rs.getString("productid"));
                f.setName(rs.getString("name"));
                f.setCategory(rs.getString("category"));
                f.setImage(rs.getString("image"));
                f.setPrice(rs.getDouble("price"));
                f.setDescn(rs.getString("descn"));

                return f;
            }

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (pstmt != null) {
                try {
                    pstmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }


        return null;
    }
    
  //按名字查询
    @Override
    public List<Flower> findByCategory(String category) {
        // TODO 自动生成的方法存根
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;

        List<Flower> list = new ArrayList<Flower>();
        String sql = "select productid,name,category,image,price,descn from flower where category=?";

        try {
            // 2.创建数据库连接
            conn = Jdbc.getConnection();// 1.加载驱动程序
            // 3.创建语句对象
            pstmt = conn.prepareStatement(sql);
            // 4.绑定参数
            pstmt.setString(1,category);
            // 5.执行查询
            rs = pstmt.executeQuery();
            // 6.遍历按主键查询
            while (rs.next()) {

                Flower f = new Flower();

                f.setProductid(rs.getString("productid"));
                f.setName(rs.getString("name"));
                f.setCategory(rs.getString("category"));
                f.setImage(rs.getString("image"));
                f.setPrice(rs.getDouble("price"));
                f.setDescn(rs.getString("descn"));

                list.add(f);
            }

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (pstmt != null) {
                try {
                    pstmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
        return list;

    }
    @Override
	public int create(Flower flower) {

		String sql = "insert into flower(productid,name,category,image,price,descn) values (?,?,?,?,?,?)";

		try ( // 2.创建数据库连接
				Connection conn = Jdbc.getConnection();
				// 3.创建语句对象
				PreparedStatement pstmt = conn.prepareStatement(sql);) {
			// 4.绑定参数
			pstmt.setString(1, flower.getProductid());
			pstmt.setString(2, flower.getName());
			pstmt.setString(3, flower.getCategory());
			pstmt.setString(4, flower.getImage());
			pstmt.setDouble(5, flower.getPrice());
			pstmt.setString(6, flower.getDescn());

			// 5.执行
			int executeUpdate = pstmt.executeUpdate();
			System.out.printf("成功插入%d数据\n", executeUpdate);

		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}

		return 0;
	}

	@Override
	public int modify(Flower flower) {

		String sql = "update flower set price = ? where productid = ?";

		try ( // 2.创建数据库连接
				Connection conn = Jdbc.getConnection();
				// 3. 创建语句对象
				PreparedStatement pstmt = conn.prepareStatement(sql)) {
			// 4. 绑定参数

			pstmt.setDouble(1, flower.getPrice());
			pstmt.setString(2, flower.getProductid());

			// 5. 执行修改（C、U、D）
			int executeUpdate = pstmt.executeUpdate();
			System.out.printf("成功更新%d条数据。\n", executeUpdate);
		} catch (SQLException e) {
			e.printStackTrace();
		}

		return 0;
	}

	@Override
	public int remove(Flower flower) {

		String sql = "delete from flower where productid = ?";

		try ( // 2.创建数据库连接
				Connection conn = Jdbc.getConnection();
				// 3. 创建语句对象
				PreparedStatement pstmt = conn.prepareStatement(sql)) {

			// 4. 绑定参数
			pstmt.setString(1, flower.getProductid());

			// 5. 执行修改（C、U、D）
			int executeUpdate = pstmt.executeUpdate();
			System.out.printf("成功删除%d条数据。\n", executeUpdate);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return 0;
	}


}