情况

我正在使用 mysql 数据库。查询从 phpmyadmin 和 postman 运行

但是当我从 android 发送请求时(它返回零行)

我已经记录了从 android 发送的电子邮件是正确的并且适用于其他查询但不是这个

    public function isUserExists($email, $u_name) {
    $stmt = $this->conn->prepare("select * from login where email_id = ?");                          
     $stmt->bind_param("s",$email);
    $stmt->execute();
    $stmt->store_result();
    $num_rows = $stmt->num_rows; //getting no of rows if exits
    $stmt->close();
    return $num_rows > 0;
}

câu hỏi

为什么这不起作用，即使正确的电子邮件是从 android 发送并在 php 中成功获取它

我们从 android 发送的电子邮件在所有其他查询和方法中都能完美运行

biên tập我正在使用这个类来发送我的帖子请求

public class WebConnector {
    String boundary = "-------------" + System.currentTimeMillis();
    private static final String LINE_FEED = "\r\n";
    private static final String TWO_HYPHENS = "--";




    private StringBuilder url;
    private String api_key;
    private HashMap params = new HashMap<>();
    File file;

    private int count = 0;
    private DataOutputStream dos;
    JSONObject postData;

    public void addParams(String key , String value) {
     params.put(key,value);
    }
    public WebConnector(StringBuilder url, String api_key)
    {
        this.url = url;
        this.api_key = api_key;
        this.postData = new JSONObject();
        this.file = null;
    }
    public WebConnector(StringBuilder url, String api_key, JSONObject postData)
    {
        this.url = url;
        this.api_key = api_key;
        this.postData = postData;
        this.file = null;
    }


    public WebConnector(StringBuilder url, String api_key, JSONObject postData, File image) {
        siêu();
        this.url = url;
        this.postData = postData;
        this.api_key = api_key;
        this.file = image;

    }


    public String connectToMULTIPART_POST_service(String requestMethod) {
        createServiceUrl();

        System.out.println(">>>>>>>>>url : " + url);



        String strResponse = "";
        InputStream inputStream = null;
        HttpURLConnection urlConnection = null;

        thử {
            urlConnection = (HttpURLConnection) new URL(url.toString()).openConnection();
            urlConnection.setRequestProperty("Content-Type", "application/json");
            urlConnection.setRequestProperty("Connection", "close");
            urlConnection.setRequestProperty("User-Agent", "Mozilla/5.0 ( compatible ) ");
            urlConnection.setRequestProperty("Authorization", "" + api_key);

            urlConnection.setRequestMethod(requestMethod);

            if(requestMethod.equals("GET") || requestMethod.equals("DELETE"))
            urlConnection.setDoOutput(false);
            else {
                urlConnection.setRequestProperty("Content-type", "multipart/form-data; boundary=" + boundary);
                urlConnection.setDoOutput(true);

                urlConnection.setDoInput(true);
                urlConnection.setUseCaches(false);
                urlConnection.setChunkedStreamingMode(1024);

                dos = new DataOutputStream(urlConnection.getOutputStream());
                Iterator keys = postData.keys();
                while (keys.hasNext()) {
                    thử {
                        String id = String.valueOf(keys.next());
                        addFormField(id, postData.get(id).toString());
                        System.out.println(id + " : " + postData.get(id));
                    } bắt (JSONException e) {
                        e.printStackTrace();
                    }
                }
                thử {

                    dos.flush();
                } bắt (IOException e) {
                    e.printStackTrace();
                }

                if (file != null)
                    addFilePart("url", file);

                build();
            }
            urlConnection.connect();
            int statusCode = 0;
            thử {
                urlConnection.connect();
                statusCode = urlConnection.getResponseCode();
            } catch (EOFException e1) {
                if (count < 5) {
                    urlConnection.disconnect();
                    đếm++;
                    String temp = connectToMULTIPART_POST_service(requestMethod);
                    if (temp != null && !temp.equals("")) {
                        return temp;
                    }
                }
            } bắt (IOException e) {
                e.printStackTrace();
            }
            // 200 represents HTTP OK
            if (statusCode >=400) {
                inputStream = new BufferedInputStream(urlConnection.getErrorStream());
                strResponse = readStream(inputStream);
            } khác {
                System.out.println(urlConnection.getResponseMessage());
                inputStream = new BufferedInputStream(urlConnection.getInputStream());
                strResponse = readStream(inputStream);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            thử {
                if (null != inputStream)
                    inputStream.close();
            } bắt (IOException e) {
            }
        }

        return strResponse;
    }


    public void addFormField(String fieldName, String value) {
        thử {
            dos.writeBytes(TWO_HYPHENS + boundary + LINE_FEED);
            dos.writeBytes("Content-Disposition: form-data; name=\"" + fieldName + "\"" + LINE_FEED + LINE_FEED/*+ value + LINE_FEED*/);
            /*dos.writeBytes("Content-Type: text/plain; charset=UTF-8" + LINE_FEED);*/
            dos.writeBytes(value + LINE_FEED);
        } bắt (IOException e) {
            e.printStackTrace();
        }

    }

    public void addFilePart(String fieldName, File uploadFile) {
        thử {
            dos.writeBytes(TWO_HYPHENS + boundary + LINE_FEED);
            dos.writeBytes("Content-Disposition: form-data; name=\"" + fieldName + "\";filename=\"" + uploadFile.getName() + "\"" + LINE_FEED);
            dos.writeBytes(LINE_FEED);

            FileInputStream fStream = new FileInputStream(uploadFile);
            int bufferSize = 1024;
            byte[] buffer = new byte[bufferSize];
            int length = -1;

            while ((length = fStream.read(buffer)) != -1) {
                dos.write(buffer, 0, length);
            }
            dos.writeBytes(LINE_FEED);
            dos.writeBytes(TWO_HYPHENS + boundary + TWO_HYPHENS + LINE_FEED);
        /* close streams */
            fStream.close();
        } bắt (IOException e) {
            e.printStackTrace();
        }
    }

    public void addHeaderField(String name, String value) {
        thử {
            dos.writeBytes(name + ": " + value + LINE_FEED);
        } bắt (IOException e) {
            e.printStackTrace();
        }

    }

    public void build() {
        thử {
            dos.writeBytes(LINE_FEED);
            dos.flush();
            dos.close();
        } bắt (IOException e) {
            e.printStackTrace();
        }
    }

    private static String readStream(InputStream in) {
        StringBuilder sb = new StringBuilder();
        thử {
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            String nextLine = "";
            while ((nextLine = reader.readLine()) != null) {
                sb.append(nextLine);
            }
        /* Close Stream */
            if (null != in) {
                ghim theo();
            }
        } bắt (IOException e) {
            e.printStackTrace();
        }

        return sb.toString();
    }

    private void createServiceUrl() {
        if (null == params) {
            return;
        }
        final Iterator<>> it = params.entrySet().iterator();
        boolean isParam = false;
        while (it.hasNext()) {
            final Map.Entry mapEnt = (Map.Entry) it.next();
            url.append(mapEnt.getKey());
            url.append("=");
            thử {
                url.append(URLEncoder.encode(mapEnt.getValue(), "UTF-8"));
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (NullPointerException e) {
                e.printStackTrace();
            }
            url.append("&");//%20
            isParam = true;
        }
        if (isParam) {
            url.deleteCharAt(url.length() - 1);
        }
    }
    //localhost/LumnuOirtal/event?event=1&descip=wdsdsdsd&

}

1 Câu trả lời

我认为问题出在“bindParam”语句中。你的声明说要替换“s”而不是“？”。试试这个:

$stmt = $this->conn->prepare("select * from login where email_id = ?");
$stmt->bind_param("?",$email);

hoặc

$stmt = $this->conn->prepare("select * from login where email_id = :email");
$stmt->bind_param(":email",$email);

关于php - 查询从 postman 和 phpmyadmin 运行，但不是从 android 运行，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/38849604/