ADD file via upload

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<Coursemqsy> findAllqsy() {
+		String sql = "select id,name,jieshao from t_kecheng";
+		List<Coursemqsy> coursemqsy = new ArrayList<Coursemqsy>();
+
+		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
+	    }
+	}
+}