Question

我有这个代码使用C＃来操作SQL Server中的数据

using (SqlConnection myDatabaseConnection = new SqlConnection(myConnectionString.ConnectionString))
            {
                myDatabaseConnection.Open();
                using (SqlCommand SqlCommand = new SqlCommand("Select * from Users where Username = @UserName and Password = @Password", myDatabaseConnection))
                {
                    SqlCommand.CommandType = CommandType.Text;
                    SqlCommand.Parameters.AddWithValue("@UserName", TextBox1.Text);
                    SqlCommand.Parameters.AddWithValue("@Password", TextBox2.Text);
                    SqlDataReader DR1 = SqlCommand.ExecuteReader();
                    if (DR1.Read())
                    {
                    //somecodes
                    }
                }
             }

如何使用JDBC和MySQL作为数据库将其转换为Java？并且可以避免SQL注入。

试验：

try (Connection conn = DriverManager.getConnection(dbURL, username, password)) {
            String sql = "Select * from Users where Username = @UserName and Password = @Password";
            Statement statement = conn.createStatement();
            //parameters?
            ResultSet result = statement.executeQuery(sql);
            while (result.next()){
                //somecode
            }

        } catch (SQLException ex) {
            ex.printStackTrace();
        }

Answer 1

JDBC使用?个字符作为占位符，绑定变量通常会占用。您必须使用PreparedStatement来使用?占位符。然后你可以调用setXXX方法（这里有基于1的索引！）来绑定变量然后执行。

String sql = "Select * from Users where Username = ? and Password = ?";
PreparedStatement pStatement = conn.prepareStatement(sql);
pStatement.setString(1, username);
pStatement.setString(2, password);
ResultSet rs = statement.executeQuery();

从C＃转换为Java JDBC

1 个答案: