ADD file via upload

ZhuanyeDaoImpWR.java

@@ -0,0 +1,140 @@
+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.ZhuanyeDaoWR;
+import com.WR.StudentMS.model.ZhuanyeWR;
+
+public class ZhuanyeDaoImpWR implements ZhuanyeDaoWR {
+
+	@Override
+	public List<ZhuanyeWR> findAll() {
+		// TODO 自动生成的方法存根
+		String sql = "select id,name,jieshao from t_zhuanye";
+        List<ZhuanyeWR> list = new ArrayList<ZhuanyeWR>();
+        try(
+                Connection conn = DBHelper.getConnection();//TODO
+                PreparedStatement pstmt = conn.prepareStatement(sql);
+                ResultSet rs = pstmt.executeQuery(); ){
+            while(rs.next()) {
+            	ZhuanyeWR zhuanyewr = new ZhuanyeWR();
+            	zhuanyewr.setId(rs.getInt("id"));
+            	zhuanyewr.setName(rs.getString("name"));
+            	zhuanyewr.setJieshao(rs.getString("jieshao"));
+                list.add(zhuanyewr);
+            }
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+	return list;
+	}
+
+	@Override
+	public ZhuanyeWR findById(int id) {
+		// TODO 自动生成的方法存根
+		Connection conn = null;
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+
+        try {
+            conn = DBHelper.getConnection();
+            String sql = "select id,name,jieshao from t_zhuanye where id = ?";
+            pstmt = conn.prepareStatement(sql);
+            pstmt.setInt(1, id);
+            rs = pstmt.executeQuery();
+            if (rs.next()) {
+            	ZhuanyeWR zhuanyewr = new ZhuanyeWR();
+            	zhuanyewr.setId(rs.getInt("id"));
+            	zhuanyewr.setName(rs.getString("name"));
+            	zhuanyewr.setJieshao(rs.getString("jieshao"));
+                return zhuanyewr;
+            }
+
+        } catch (SQLException e) {
+            e.printStackTrace();
+        } finally {
+            try {
+                DBHelper.close(rs, pstmt, conn);
+            } catch (SQLException e) {
+                // TODO Auto-generated catch block
+                e.printStackTrace();
+            }
+        }
+		return null;
+	}
+
+
+	@Override
+	public int create(ZhuanyeWR zhuanyewr) {
+	    // 检查ID是否已存在
+	    String checkSql = "SELECT COUNT(*) FROM t_zhuanye WHERE id = ?";
+	    try (Connection conn = DBHelper.getConnection();
+	         PreparedStatement checkStmt = conn.prepareStatement(checkSql)) {
+	        checkStmt.setInt(1, zhuanyewr.getId());
+	        ResultSet rs = checkStmt.executeQuery();
+	        if (rs.next() && rs.getInt(1) > 0) {
+	            // 如果ID已存在，则返回提示
+	            return 0; // 0通常表示操作没有影响任何行
+	        }
+	    } catch (SQLException e) {
+	        e.printStackTrace();
+	        return -1;
+	    }
+
+	    // 继续执行插入操作
+	    String sql = "INSERT INTO t_zhuanye (id, name, jieshao) VALUES (?, ?, ?)";
+	    try (Connection conn = DBHelper.getConnection();
+	         PreparedStatement pstmt = conn.prepareStatement(sql)) {
+	        pstmt.setInt(1, zhuanyewr.getId());
+	        pstmt.setString(2, zhuanyewr.getName());
+	        pstmt.setString(3, zhuanyewr.getJieshao());
+	        int executeUpdate = pstmt.executeUpdate();
+	        return executeUpdate;
+	    } catch (SQLException e) {
+	        e.printStackTrace();
+	        return -1;
+	    }
+	}
+
+	@Override
+	public int remove(ZhuanyeWR zhuanyewr) {
+		String sql = "DELETE FROM t_zhuanye WHERE id = ?";
+		try (
+	        Connection conn = DBHelper.getConnection();
+	        PreparedStatement pstmt = conn.prepareStatement(sql)
+	    ) {
+	        pstmt.setInt(1, zhuanyewr.getId()); // 假设stu_id是外键，与专业ID相关联
+	        int affectedRows = pstmt.executeUpdate();
+	        System.out.printf("删除%d条数据。\n", affectedRows);
+	        return affectedRows;
+	    } catch (SQLException e) {
+	        e.printStackTrace();
+	        return -1;
+	    }
+	}
+	@Override
+	public int modify(ZhuanyeWR zhuanyewr) {
+	    String sql = "UPDATE t_zhuanye SET name = ?, jieshao = ? WHERE id = ?";
+	    try (
+	        Connection conn = DBHelper.getConnection();
+	        PreparedStatement pstmt = conn.prepareStatement(sql);
+	    ) {
+	        pstmt.setString(1, zhuanyewr.getName());
+	        pstmt.setString(2, zhuanyewr.getJieshao());
+	        pstmt.setInt(3, zhuanyewr.getId());
+	        int affectedRows = pstmt.executeUpdate();
+	        System.out.printf("更新%d条数据。\n", affectedRows);
+	        return affectedRows;
+	    } catch (SQLException e) {
+	        // 可以在这里添加更详细的错误处理
+	        e.printStackTrace();
+	        return -1;
+	    }
+	}
+
+}