javaweb中增、刪、改、查方法

1.添加

public int addept(department dept) {
		conn=dao.getConnection();
		int count=0;
		String sql="insert into t_dept(p_name) values(?)";
		try {
			pstmt=conn.prepareStatement(sql);
			pstmt.setString(1,dept.getPname());
			count=pstmt.executeUpdate();
			if(count!=0){
				System.out.println("** 添加成功 **");
			}
			else{
				System.out.println("** 添加失敗 **");
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return count;
	}

2.刪除

public int deldept(department dept) {
		conn=dao.getConnection();
		int count=0;
		String sql="delete from t_dept where p_id=?";
		try {
			pstmt=conn.prepareStatement(sql);
			pstmt.setInt(1,dept.getPid());
			count=pstmt.executeUpdate();
			if(count!=0){
				System.out.println("** 刪除成功 **");
			}
			else{
				System.out.println("** 刪除失敗 **");
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return count;
	}

3.根據ID查詢信息

public Map alldeptById(department dept) {
		conn=dao.getConnection();
		Map map=new HashMap();
		String sql="select * from t_dept where p_id=?";
		try {
			pstmt=conn.prepareStatement(sql);
			pstmt.setInt(1,dept.getPid());
			rs=pstmt.executeQuery();
			while(rs.next()){
				map.put("pid",rs.getInt("p_id"));
				map.put("pname",rs.getString("p_name"));
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return map;
	}

4.修改

public int uppdept(department dept) {
		conn=dao.getConnection();
		int count=0;
		String sql="update t_dept set p_name=? where p_id=?";
		try {
			pstmt=conn.prepareStatement(sql);
			pstmt.setString(1,dept.getPname());
			pstmt.setInt(2,dept.getPid());
			count=pstmt.executeUpdate();
			if(count!=0){
				System.out.println("** 修改成功 **");
			}
			else{
				System.out.println("** 修改失敗 **");
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return count;
	}

5.全查詢

public List<department> alldept() {
		conn=dao.getConnection();
		String sql="select * from t_dept";
		List<department> list=new ArrayList<department>();
		try {
			pstmt=conn.prepareStatement(sql);
			rs=pstmt.executeQuery();
			while(rs.next()){
				department dept=new department();
				dept.setPid(rs.getInt("p_id"));
				dept.setPname(rs.getString("p_name"));
				list.add(dept);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return list;
	}

6.統計總記錄

public int getTotalPage() {
		int count=0;
		conn=dao.getConnection();
		String sql="select count(*) from t_dept";
		try {
			pstmt=conn.prepareStatement(sql);
			rs=pstmt.executeQuery();
			while(rs.next()){
				count=rs.getInt(1);
			}
			count=(int)Math.ceil((count+1.0-1.0)/DATA_PER_PAGE);//4
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return count;
	}

7.分頁查詢

public List<department> getpadingByPage(int cur){
		conn=dao.getConnection();
		List<department> list=new ArrayList<department>();
		String sql="select * from t_dept limit ?,?";
		try {
			pstmt=conn.prepareStatement(sql);
			pstmt.setInt(1, (cur - 1) * DATA_PER_PAGE);
			pstmt.setInt(2, DATA_PER_PAGE);
			rs=pstmt.executeQuery();
			while(rs.next()){
				department dept=new department();
				dept.setPid(rs.getInt("p_id"));
				dept.setPname(rs.getString("p_name"));
				list.add(dept);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return list;
	}

8.用戶登錄

public int logemp(String uname, String pwd) {
		int count=0;
		conn=dao.getConnection();
		String sql="select count(*) from t_user where t_username='"+uname+"' and t_password='"+pwd+"'";
		try {
			pstmt=conn.prepareStatement(sql);
			rs=pstmt.executeQuery();
			while(rs.next()){
				count=rs.getInt(1);
				if(count!=0){
					System.out.println("** 登錄成功 **");
				}
				else{
					System.out.println("** 登錄失敗 **");
				}
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return count;
	}