diff --git a/Coursemdaoimplqsy.java b/Coursemdaoimplqsy.java new file mode 100644 index 0000000..d87e4d8 --- /dev/null +++ b/Coursemdaoimplqsy.java @@ -0,0 +1,107 @@ +package com.WR.StudentMS.dao.mysql; + +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 com.WR.StudentMS.dao.Coursemdaoqsy; +import com.WR.StudentMS.model.Coursemqsy; + + +public class Coursemdaoimplqsy implements Coursemdaoqsy { + + @Override + public List findAllqsy() { + String sql = "select id,name,jieshao from t_kecheng"; + List coursemqsy = new ArrayList(); + + try ( + + Connection conn = DBHelper.getConnection(); + + PreparedStatement pstmt = conn.prepareStatement(sql); + + + ResultSet rs = pstmt.executeQuery()) { + + + while (rs.next()) { + Coursemqsy coursem = new Coursemqsy(); + coursem.setCourseidqsy(rs.getString("id")); + coursem.setCoursenameqsy(rs.getString("name")); + coursem.setJieshaoqsy(rs.getString("jieshao")); + coursemqsy.add(coursem); + } + + } catch (SQLException e) { + e.printStackTrace(); + } + return coursemqsy; + } + + @Override + public Coursemqsy findByIdqsy(String courseid) { + String sql = "SELECT id, name, jieshao FROM t_kecheng WHERE id = ?"; + try ( + Connection conn = DBHelper.getConnection(); + PreparedStatement pstmt = conn.prepareStatement(sql); + ) { + pstmt.setString(1, courseid); + ResultSet rs = pstmt.executeQuery(); + if (rs.next()) { + Coursemqsy coursem = new Coursemqsy(); + coursem.setCourseidqsy(rs.getString("id")); + coursem.setCoursenameqsy(rs.getString("name")); + coursem.setJieshaoqsy(rs.getString("jieshao")); + return coursem; + } + } catch (SQLException e) { + e.printStackTrace(); + } + return null; + } + + + @Override + public int createqsy(Coursemqsy coursem) { + String sql = "insert into t_kecheng (id, name, jieshao) values (?,?,?)"; + try ( + Connection conn = DBHelper.getConnection(); + PreparedStatement pstmt = conn.prepareStatement(sql) + ) { + pstmt.setString(1, coursem.getCourseidqsy()); + pstmt.setString(2, coursem.getCoursenameqsy()); + pstmt.setString(3, coursem.getJieshaoqsy()); // 确保这里的占位符数量与SQL语句中的一致 + + int affectedRows = pstmt.executeUpdate(); + System.out.printf("成功插入%d条数据\n", affectedRows); + return affectedRows; // 如果插入成功,返回受影响的行数 + } catch (SQLException e) { + // 打印异常信息,以便于调试 + e.printStackTrace(); + // 如果发生异常,返回-1表示操作失败 + return -1; + } + } + + + @Override + public int removeqsy(Coursemqsy coursem) { + String sql = "delete from t_kecheng where id = ?"; // 只使用 id 作为删除条件 + try ( + Connection conn = DBHelper.getConnection(); + PreparedStatement pstmt = conn.prepareStatement(sql) + ) { + pstmt.setString(1, coursem.getCourseidqsy()); // 设置要删除的课程的 id + int affectedRows = pstmt.executeUpdate(); + System.out.printf("成功删除%d条数据\n", affectedRows); // 修正控制台输出信息 + return affectedRows; // 返回受影响的行数 + } catch (SQLException e) { + e.printStackTrace(); // 打印异常信息 + return -1; // 发生异常时返回-1 + } + } +}