我有五个表名图书，类别，出版物，作者，评论
在我的应用用户可以在登录后查看该书。所以评论表保持空白，直到用户发表评论为止。
我正在尝试在codeigniter模型中运行流动查询以通过category_id获取书籍详细信息，并且当它们的评论存在时它工作正常，否则它将返回空数组。发生这种情况的原因是$this>db>join('reviews','reviews.book_id = books.book_id');条件返回false
我怎样才能显示结果甚至评论表条件不匹配？
public function get_book_details($cat_id) {
$this->db->select('*');
$this->db->from('books');
$this->db->join('categories', 'categories.id = books.category_id');
$this->db->join('publications', 'publications.id = books.publication_id');
$this->db->join('author', 'author.id = books.author_id');
$this->db->join('reviews', 'reviews.book_id = books.book_id');
$this->db->where('categories.id', $cat_id);
$query = $this->db->get();
return $query->result();
}
答案 0 :(得分：0)
如果找不到匹配的关联，请使用$this->db->join('reviews', 'reviews.book_id = books.book_id','LEFT');
获取结果
Img_profile_pic.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (Build.VERSION.SDK_INT >= 23) {
// Marshmallow+
if (!checkAccessFineLocationPermission() || !checkWriteExternalStoragePermission()) {
requestPermission();
} else {
chooseimage();
}
} else {
chooseimage();
}
}
});
}
private void takePicture() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
camera_FileUri = getOutputMediaFileUri(1);
intent.putExtra(MediaStore.EXTRA_OUTPUT, camera_FileUri);
// start the image capture Intent
startActivityForResult(intent, REQUEST_TAKE_PHOTO);
}
private void openGallery() {
Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, galleryRequestCode);
}
/**
* Creating file uri to store image/video
*/
public Uri getOutputMediaFileUri(int type) {
return Uri.fromFile(getOutputMediaFile(type));
}
/**
* returning image / video
*/
private static File getOutputMediaFile(int type) {
// External sdcard location
File mediaStorageDir = new File(
Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), IMAGE_DIRECTORY_NAME);
// Create the storage directory if it does not exist
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d(TAG, "Oops! Failed create "
+ IMAGE_DIRECTORY_NAME + " directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
Locale.getDefault()).format(new Date());
File mediaFile;
if (type == 1) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator
+ "IMG_" + timeStamp + ".jpg");
} else {
return null;
}
return mediaFile;
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// save file url in bundle as it will be null on screen orientation
// changes
outState.putParcelable("file_uri", camera_FileUri);
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// get the file url
camera_FileUri = savedInstanceState.getParcelable("file_uri");
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == REQUEST_TAKE_PHOTO || requestCode == UCrop.REQUEST_CROP) {
try {
if (requestCode == REQUEST_TAKE_PHOTO) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;
final Bitmap bitmap = BitmapFactory.decodeFile(camera_FileUri.getPath(), options);
Bitmap thumbnail = bitmap;
final String picturePath = camera_FileUri.getPath();
// ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
File curFile = new File(picturePath);
try {
ExifInterface exif = new ExifInterface(curFile.getPath());
int rotation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
int rotationInDegrees = exifToDegrees(rotation);
Matrix matrix = new Matrix();
if (rotation != 0f) {
matrix.preRotate(rotationInDegrees);
}
// thumbnail = Bitmap.createBitmap(thumbnail, 0, 0, thumbnail.getWidth(), thumbnail.getHeight(), matrix, true);
} catch (IOException ex) {
Log.e("TAG", "Failed to get Exif data", ex);
}
System.out.println("edit-----" + Iconstant.Edit_profile_image_url);
Uri picUri = Uri.fromFile(curFile);
UCrop.of(picUri, picUri)
.withAspectRatio(4, 4)
.withMaxResultSize(8000, 8000)
.start(ProfilePage.this);
}
} catch (Exception e) {
e.printStackTrace();
}
} else if (requestCode == galleryRequestCode) {
Uri selectedImage = data.getData();
if (selectedImage.toString().startsWith("content://com.sec.android.gallery3d.provider")) {
String[] filePath = {MediaStore.Images.Media.DATA};
Cursor c = getContentResolver().query(selectedImage, filePath, null, null, null);
c.moveToFirst();
int columnIndex = c.getColumnIndex(filePath[0]);
final String picturePath = c.getString(columnIndex);
c.close();
File curFile = new File(picturePath);
Picasso.with(ProfilePage.this).load(picturePath).resize(100, 100).into(new Target() {
@Override
public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
Bitmap thumbnail = bitmap;
mSelectedFilePath = picturePath;
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
thumbnail.compress(Bitmap.CompressFormat.JPEG, 70, byteArrayOutputStream);
}
@Override
public void onBitmapFailed(Drawable errorDrawable) {
}
@Override
public void onPrepareLoad(Drawable placeHolderDrawable) {
}
});
Uri picUri = Uri.fromFile(curFile);
UCrop.of(picUri, picUri)
.withAspectRatio(4, 4)
.withMaxResultSize(8000, 8000)
.start(ProfilePage.this);
} else {
String[] filePath = {MediaStore.Images.Media.DATA};
Cursor c = getContentResolver().query(selectedImage, filePath, null, null, null);
c.moveToFirst();
int columnIndex = c.getColumnIndex(filePath[0]);
final String picturePath = c.getString(columnIndex);
Bitmap bitmap = BitmapFactory.decodeFile(picturePath);
Bitmap thumbnail = bitmap; //getResizedBitmap(bitmap, 600);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
File curFile = new File(picturePath);
try {
ExifInterface exif = new ExifInterface(curFile.getPath());
int rotation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
int rotationInDegrees = exifToDegrees(rotation);
Matrix matrix = new Matrix();
if (rotation != 0f) {
matrix.preRotate(rotationInDegrees);
}
thumbnail = Bitmap.createBitmap(thumbnail, 0, 0, thumbnail.getWidth(), thumbnail.getHeight(), matrix, true);
} catch (IOException ex) {
Log.e("TAG", "Failed to get Exif data", ex);
}
thumbnail.compress(Bitmap.CompressFormat.JPEG, 70, byteArrayOutputStream);
c.close();
Uri picUri = Uri.fromFile(curFile);
UCrop.of(picUri, picUri)
.withAspectRatio(4, 4)
.withMaxResultSize(8000, 8000)
.start(ProfilePage.this);
}
}
if ( requestCode == UCrop.REQUEST_CROP) {
final Uri resultUri = UCrop.getOutput(data);
try {
selectedBitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), resultUri);
} catch (IOException e) {
e.printStackTrace();
}
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
selectedBitmap.compress(Bitmap.CompressFormat.JPEG, 70, byteArrayOutputStream);
byteArray = byteArrayOutputStream.toByteArray();
Img_profile_pic.setImageBitmap(selectedBitmap);
Img_profile_pic.setImageURI(resultUri);
UploadDriverImage(Iconstant.Edit_profile_image_url);
} else if (resultCode == UCrop.RESULT_ERROR) {
final Throwable cropError = UCrop.getError(data);
System.out.println("========muruga cropError==========="+cropError);
}
}
}
private static int exifToDegrees(int exifOrientation) {
if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_90) {
return 90;
} else if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_180) {
return 180;
} else if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_270) {
return 270;
}
return 0;
}
private void UploadDriverImage(String url) {
dialog = new Dialog(ProfilePage.this);
dialog.getWindow();
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.custom_loading);
dialog.setCanceledOnTouchOutside(false);
dialog.show();
TextView dialog_title = (TextView) dialog.findViewById(R.id.custom_loading_textview);
dialog_title.setText(getResources().getString(R.string.action_loading));
VolleyMultipartRequest multipartRequest = new VolleyMultipartRequest(Request.Method.POST, url, new Response.Listener<NetworkResponse>() {
@Override
public void onResponse(NetworkResponse response) {
System.out.println("------------- image response-----------------"+response.data);
String resultResponse = new String(response.data);
System.out.println("------------- response-----------------"+resultResponse);
String sStatus = "", sResponse = "",SUser_image="",Smsg="";
try {
JSONObject jsonObject = new JSONObject(resultResponse);
sStatus = jsonObject.getString("status");
if (sStatus.equalsIgnoreCase("1")) {
// JSONObject responseObject = jsonObject.getJSONObject("response");
// SUser_image = jsonObject.getString("image");
Smsg = jsonObject.getString("image_url");
// Img_profile_pic.setImageBitmap(bitMapThumbnail);
session.setuser_image(Smsg);
Picasso.with(ProfilePage.this).load(Smsg).placeholder(R.drawable.no_user_image).into(Img_profile_pic);
NavigationDrawer.navigationNotifyChange();
Locale locale = null;
switch (language_code){
case "en":
locale = new Locale("en");
session.setlamguage("en","en");
break;
case "es":
locale = new Locale("es");
session.setlamguage("es","es");
// session.setlamguage("Ar",language_change.getSelectedItem().toString());
// System.out.println("========Arabic Language========"+language_change.getSelectedItem().toString()+"\t\tar");
// Intent i=new Intent(ProfilePage.this,NavigationDrawer.class);
// finish();
// startActivity(i);
// Intent bii = new Intent();
// bii.setAction("homepage");
// sendBroadcast(bii);
// finish();
break;
case "ta":
locale = new Locale("ta");
session.setlamguage("ta","ta");
// session.setlamguage("Ar",language_change.getSelectedItem().toString());
// System.out.println("========Arabic Language========"+language_change.getSelectedItem().toString()+"\t\tar");
// Intent i=new Intent(ProfilePage.this,NavigationDrawer.class);
// finish();
// startActivity(i);
// Intent bii = new Intent();
// bii.setAction("homepage");
// sendBroadcast(bii);
// finish();
break;
default:
locale = new Locale("en");
session.setlamguage("en","en");
break;
}
Locale.setDefault(locale);
Configuration config = new Configuration();
config.locale = locale;
getApplicationContext().getResources().updateConfiguration(config, getApplicationContext().getResources().getDisplayMetrics());
Alert(getResources().getString(R.string.action_success),getResources().getString(R.string.edit_profile_success_label));
} else {
sResponse = jsonObject.getString("response");
Alert(getResources().getString(R.string.my_rides_rating_header_sorry_textview), sResponse);
}
} catch (JSONException e) {
e.printStackTrace();
}
catch (Exception e) {
Toast.makeText(ProfilePage.this,"Something happened , try again",Toast.LENGTH_LONG).show();
e.printStackTrace();
}
dialog.dismiss();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
dialog.dismiss();
NetworkResponse networkResponse = error.networkResponse;
String errorMessage = "Unknown error";
if (networkResponse == null) {
if (error.getClass().equals(TimeoutError.class)) {
errorMessage = "Request timeout";
} else if (error.getClass().equals(NoConnectionError.class)) {
errorMessage = "Failed to connect server";
}
} else {
String result = new String(networkResponse.data);
try {
JSONObject response = new JSONObject(result);
String status = response.getString("status");
String message = response.getString("message");
Log.e("Error Status", status);
Log.e("Error Message", message);
if (networkResponse.statusCode == 404) {
errorMessage = "Resource not found";
} else if (networkResponse.statusCode == 401) {
errorMessage = message + " Please login again";
} else if (networkResponse.statusCode == 400) {
errorMessage = message + " Check your inputs";
} else if (networkResponse.statusCode == 500) {
errorMessage = message + " Something is getting wrong";
}
} catch (JSONException e) {
e.printStackTrace();
}
}
Log.i("Error", errorMessage);
error.printStackTrace();
}
}) {
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
System.out.println("------------Authkey------cabily---------" + Agent_Name);
System.out.println("------------userid----------cabily-----" + UserID);
System.out.println("------------apptoken----------cabily-----" + gcmID);
System.out.println("------------applanguage----------cabily-----" + language_code);
Map<String, String> headers = new HashMap<String, String>();
headers.put("Authkey", Agent_Name);
headers.put("isapplication",Iconstant.cabily_IsApplication);
headers.put("applanguage",language_code);
headers.put("apptype", Iconstant.cabily_AppType);
headers.put("userid",UserID);
headers.put("apptoken",gcmID);
/* System.out.println("servicereques apptype------------------"+Iconstant.cabily_AppType);
System.out.println("servicereques apptoken------------------"+gcmID);
System.out.println("servicereques userid------------------"+UserID);
Map<String, String> headers = new HashMap<String, String>();
headers.put("User-agent",Iconstant.cabily_userAgent);
headers.put("isapplication",Iconstant.cabily_IsApplication);
headers.put("applanguage",Iconstant.cabily_AppLanguage);
headers.put("apptype",Iconstant.cabily_AppType);
headers.put("apptoken",gcmID);
headers.put("userid",UserID);*/
return headers;
}
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<>();
params.put("user_id",UserID);
System.out.println("user_id---------------"+UserID);
return params;
}
@Override
protected Map<String, DataPart> getByteData() {
Map<String, DataPart> params = new HashMap<>();
params.put("user_image",new DataPart("cabily_user.jpg", byteArray));
System.out.println("user_image--------edit------"+byteArray);
return params;
}
};
//to avoid repeat request Multiple Time
DefaultRetryPolicy retryPolicy = new DefaultRetryPolicy(0, -1, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
multipartRequest.setRetryPolicy(retryPolicy);
multipartRequest.setRetryPolicy(new DefaultRetryPolicy(60000,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
multipartRequest.setShouldCache(false);
AppController.getInstance().addToRequestQueue(multipartRequest);
}
// --------------------Method for choose image to edit profileimage--------------------
private void chooseimage() {
photo_dialog = new Dialog(ProfilePage.this);
photo_dialog.getWindow();
photo_dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
photo_dialog.setContentView(R.layout.image_upload_dialog);
photo_dialog.setCanceledOnTouchOutside(true);
photo_dialog.getWindow().getAttributes().windowAnimations = R.style.Animations_photo_Picker;
photo_dialog.show();
photo_dialog.getWindow().setGravity(Gravity.CENTER);
RelativeLayout camera = (RelativeLayout) photo_dialog
.findViewById(R.id.profilelayout_takephotofromcamera);
RelativeLayout gallery = (RelativeLayout) photo_dialog
.findViewById(R.id.profilelayout_takephotofromgallery);
camera.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
takePicture();
photo_dialog.dismiss();
}
});
gallery.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
openGallery();
photo_dialog.dismiss();
}
});
}
private boolean checkAccessFineLocationPermission() {
int result = ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
if (result == PackageManager.PERMISSION_GRANTED) {
return true;
} else {
return false;
}
}
private boolean checkAccessCoarseLocationPermission() {
int result = ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
if (result == PackageManager.PERMISSION_GRANTED) {
return true;
} else {
return false;
}
}
private boolean checkWriteExternalStoragePermission() {
int result = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);
if (result == PackageManager.PERMISSION_GRANTED) {
return true;
} else {
return false;
}
}
private void requestPermission() {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA,Manifest.permission.WRITE_EXTERNAL_STORAGE}, PERMISSION_REQUEST_CODE);
}
@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case PERMISSION_REQUEST_CODE:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED || grantResults[1] == PackageManager.PERMISSION_GRANTED ) {
chooseimage();
} else {
finish();
}
break;
}
}