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Nick Aiwazian
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Add more starter code for persistence
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‎app/src/main/java/com/codepath/instagram/persistence/InstagramClientDatabase.java‎

Lines changed: 302 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -1,22 +1,39 @@
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package com.codepath.instagram.persistence;
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3-
public class InstagramClientDatabase {
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import android.content.ContentValues;
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import android.content.Context;
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import android.database.Cursor;
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import android.database.sqlite.SQLiteDatabase;
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import android.database.sqlite.SQLiteOpenHelper;
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import android.util.Log;
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import com.codepath.instagram.models.InstagramComment;
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import com.codepath.instagram.models.InstagramImage;
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import com.codepath.instagram.models.InstagramPost;
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import com.codepath.instagram.models.InstagramUser;
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import java.util.ArrayList;
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import java.util.List;
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public class InstagramClientDatabase extends SQLiteOpenHelper {
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private static final String TAG = "InstagramClientDatabase";
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// Database info
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private static final String DATABASE_NAME = "instagramClientDatabase";
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private static final int DATABASE_VERSION = 1;
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// Tables
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private static final String TABLE_POSTS = "posts";
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private static final String TABLE_USERS = "users";
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private static final String TABLE_IMAGES = "images";
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private static final String TABLE_COMMENTS = "comments";
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private static final String TABLE_POST_COMMENTS = "postComments";
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// Constraints
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private static final String CONSTRAINT_POST_COMMENTS_PK = "postComments_pk";
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private static final String KEY_ID = "_id";
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// Posts table columns
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private static final String KEY_POST_ID = "id";
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private static final String KEY_POST_MEDIA_ID = "mediaId";
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private static final String KEY_POST_USER_ID_FK = "userId";
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private static final String KEY_POST_IMAGE_ID_FK = "imageId";
@@ -26,15 +43,18 @@ public class InstagramClientDatabase {
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private static final String KEY_POST_CREATED_TIME = "createdTime";
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// Users table columns
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private static final String KEY_USER_ID = "id";
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private static final String KEY_USER_NAME = "userName";
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private static final String KEY_USER_PROFILE_PICTURE_URL = "profilePictureUrl";
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// Images table columns
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private static final String KEY_IMAGE_ID = "id";
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private static final String KEY_IMAGE_URL = "imageUrl";
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private static final String KEY_IMAGE_HEIGHT = "imageHeight";
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private static final String KEY_IMAGE_WIDTH = "imageWidth";
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// Comments table columns
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private static final String KEY_COMMENT_ID = "id";
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private static final String KEY_COMMENT_USER_ID_FK = "userId";
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private static final String KEY_COMMENT_TEXT = "text";
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private static final String KEY_COMMENT_CREATED_TIME = "createdTime";
@@ -43,6 +63,284 @@ public class InstagramClientDatabase {
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private static final String KEY_POST_COMMENT_POST_ID_FK = "postId";
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private static final String KEY_POST_COMMENT_COMMENT_ID_FK = "commentId";
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// Singleton instance
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private static InstagramClientDatabase sInstance;
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/**
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* Constructor should be private to prevent direct instantiation.
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* make call to static method "getInstance()" instead.
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*/
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private InstagramClientDatabase(Context context) {
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super(context, DATABASE_NAME, null, DATABASE_VERSION);
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}
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public static synchronized InstagramClientDatabase getInstance(Context context) {
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if (sInstance == null) {
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// Use the application context, which will ensure that you
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// don't accidentally leak an Activity's context.
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// See this article for more information: http://bit.ly/6LRzfx
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sInstance = new InstagramClientDatabase(context.getApplicationContext());
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}
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return sInstance;
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}
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@Override
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public void onConfigure(SQLiteDatabase db) {
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super.onConfigure(db);
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db.setForeignKeyConstraintsEnabled(true);
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}
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@Override
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public void onCreate(SQLiteDatabase db) {
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String CREATE_POSTS_TABLE = "CREATE TABLE " + TABLE_POSTS +
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"(" +
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KEY_POST_ID + " INTEGER PRIMARY KEY," +
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KEY_POST_MEDIA_ID + " TEXT," +
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KEY_POST_USER_ID_FK + " INTEGER REFERENCES " + TABLE_USERS + "," +
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KEY_POST_IMAGE_ID_FK + " INTEGER REFERENCES " + TABLE_IMAGES + "," +
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KEY_POST_CAPTION + " TEXT," +
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KEY_POST_LIKES_COUNT + " INTEGER," +
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KEY_POST_COMMENTS_COUNT + " INTEGER," +
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KEY_POST_CREATED_TIME + " INTEGER" +
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")";
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String CREATE_USERS_TABLE = "CREATE TABLE " + TABLE_USERS +
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"(" +
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KEY_USER_ID + " INTEGER PRIMARY KEY," +
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KEY_USER_NAME + " TEXT UNIQUE ON CONFLICT ROLLBACK," +
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KEY_USER_PROFILE_PICTURE_URL + " TEXT" +
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")";
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String CREATE_IMAGES_TABLE = "CREATE TABLE " + TABLE_IMAGES +
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"(" +
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KEY_IMAGE_ID + " INTEGER PRIMARY KEY," +
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KEY_IMAGE_URL + " TEXT," +
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KEY_IMAGE_HEIGHT + " INTEGER," +
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KEY_IMAGE_WIDTH + " INTEGER" +
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")";
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String CREATE_COMMENTS_TABLE = "CREATE TABLE " + TABLE_COMMENTS +
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"(" +
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KEY_COMMENT_ID + " INTEGER PRIMARY KEY," +
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KEY_COMMENT_TEXT + " TEXT," +
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KEY_COMMENT_CREATED_TIME + " INTEGER," +
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KEY_COMMENT_USER_ID_FK + " INTEGER REFERENCES " + TABLE_USERS +
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")";
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String CREATE_POST_COMMENTS_TABLE = "CREATE TABLE " + TABLE_POST_COMMENTS +
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"(" +
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KEY_POST_COMMENT_POST_ID_FK + " INTEGER REFERENCES " + TABLE_POSTS + "," +
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KEY_POST_COMMENT_COMMENT_ID_FK + " INTEGER REFERENCES " + TABLE_COMMENTS + "," +
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"constraint " + CONSTRAINT_POST_COMMENTS_PK +
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" PRIMARY KEY(" +
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KEY_POST_COMMENT_POST_ID_FK + "," +
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KEY_POST_COMMENT_COMMENT_ID_FK +
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")" +
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")";
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db.execSQL(CREATE_USERS_TABLE);
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db.execSQL(CREATE_IMAGES_TABLE);
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db.execSQL(CREATE_COMMENTS_TABLE);
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db.execSQL(CREATE_POSTS_TABLE);
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db.execSQL(CREATE_POST_COMMENTS_TABLE);
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}
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@Override
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public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
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// TODO: Implement this method
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}
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public void emptyAllTables() {
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// TODO: Implement this method to delete all rows from all tables
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}
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public void addInstagramPosts(List<InstagramPost> posts) {
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// TODO: Implement this method
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// Take a look at the helper methods addImage, addComment, etc as you implement this method
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// It's also a good idea to do this work in a transaction
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}
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// Poor man's "upsert".
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// Since SQLite doesn't support "upsert" we need to fall back on an attempt to UPDATE (in case the
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// user already exists, followed by an INSERT (in case the user does not already exist).
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// Unfortunately, there is a bug with the insertOnConflict method
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// (https://code.google.com/p/android/issues/detail?id=13045) so we need to fall back to the more
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// verbose option of querying for the user's primary key if we did an update.
170+
private long addorUpdateUser(InstagramUser user) {
171+
if (user == null) {
172+
throw new IllegalArgumentException(String.format("Attemping to add a null user to %s", DATABASE_NAME));
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}
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175+
SQLiteDatabase db = getWritableDatabase();
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177+
ContentValues values = new ContentValues();
178+
values.put(KEY_USER_NAME, user.userName);
179+
values.put(KEY_USER_PROFILE_PICTURE_URL, user.profilePictureUrl);
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long userId = -1;
181+
182+
// First try to update the user in case the user already exists in DB
183+
int rows = db.update(TABLE_USERS, values, KEY_USER_NAME + "= ?", new String[] {user.userName});
184+
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// Check if update succeeded
186+
if (rows == 1) {
187+
// Get the primary key of the user we just updated
188+
String usersSelectQuery = String.format("SELECT %s FROM %s WHERE %s = ?",
189+
KEY_USER_ID, TABLE_USERS, KEY_USER_NAME);
190+
191+
Cursor usersCursor = db.rawQuery(usersSelectQuery, new String[]{String.valueOf(user.userName)});
192+
try {
193+
if (usersCursor.moveToFirst()) {
194+
userId = usersCursor.getInt(0);
195+
}
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// There should only be one user
197+
if (usersCursor.moveToNext()) {
198+
Log.wtf(TAG, "Too many primary keys returned");
199+
}
200+
} catch (Exception e) {
201+
Log.wtf(TAG, "Error while trying to add or update user");
202+
e.printStackTrace();
203+
} finally {
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usersCursor.close();
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}
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} else {
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// user with this userName did not already exist, so insert new user
208+
userId = db.insert(TABLE_USERS, null ,values);
209+
}
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211+
return userId;
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}
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214+
private long addImage(InstagramImage image) {
215+
if (image == null) {
216+
throw new IllegalArgumentException(String.format("Attemping to add a null image to %s", DATABASE_NAME));
217+
}
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219+
SQLiteDatabase db = getWritableDatabase();
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221+
ContentValues values = new ContentValues();
222+
values.put(KEY_IMAGE_URL, image.imageUrl);
223+
values.put(KEY_IMAGE_HEIGHT, image.imageHeight);
224+
values.put(KEY_IMAGE_WIDTH, image.imageHeight);
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226+
return db.insert(TABLE_IMAGES, null, values);
227+
}
228+
229+
private long addComment(InstagramComment comment, long postId) {
230+
if (comment == null) {
231+
throw new IllegalArgumentException(String.format("Attemping to add a null comment to %s", DATABASE_NAME));
232+
}
233+
SQLiteDatabase db = getWritableDatabase();
234+
235+
long commentUserId = addorUpdateUser(comment.user);
236+
237+
ContentValues values = new ContentValues();
238+
values.put(KEY_COMMENT_TEXT, comment.text);
239+
values.put(KEY_COMMENT_USER_ID_FK, commentUserId);
240+
values.put(KEY_COMMENT_CREATED_TIME, comment.createdTime);
241+
242+
long commentId = db.insert(TABLE_COMMENTS, null, values);
243+
addPostCommentMapping(postId, commentId);
244+
return commentId;
245+
}
246+
247+
private long addPostCommentMapping(long postId, long commentId) {
248+
249+
SQLiteDatabase db = getWritableDatabase();
250+
251+
ContentValues values = new ContentValues();
252+
values.put(KEY_POST_COMMENT_COMMENT_ID_FK, commentId);
253+
values.put(KEY_POST_COMMENT_POST_ID_FK, postId);
254+
255+
return db.insert(TABLE_POST_COMMENTS, null, values);
256+
}
257+
258+
public List<InstagramPost> getAllInstagramPosts() {
259+
List<InstagramPost> posts = new ArrayList<>();
260+
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String LEFT_OUTER_JOIN_FORMAT_STRING = "LEFT OUTER JOIN %s ON %s.%s = %s.%s";
262+
263+
String userJoin = String.format(LEFT_OUTER_JOIN_FORMAT_STRING,
264+
TABLE_USERS, TABLE_POSTS, KEY_POST_USER_ID_FK, TABLE_USERS, KEY_USER_ID);
265+
266+
String imageJoin = String.format(LEFT_OUTER_JOIN_FORMAT_STRING,
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TABLE_IMAGES, TABLE_POSTS, KEY_POST_IMAGE_ID_FK, TABLE_IMAGES, KEY_IMAGE_ID);
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String postsSelectQuery = "SELECT * FROM " + TABLE_POSTS + " " + userJoin + " " + imageJoin;
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String commentJoin = String.format(LEFT_OUTER_JOIN_FORMAT_STRING,
272+
TABLE_COMMENTS, TABLE_POST_COMMENTS, KEY_POST_COMMENT_COMMENT_ID_FK, TABLE_COMMENTS, KEY_COMMENT_ID);
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String commentUserJoin = String.format(LEFT_OUTER_JOIN_FORMAT_STRING,
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TABLE_USERS, TABLE_USERS, KEY_USER_ID, TABLE_COMMENTS, KEY_COMMENT_USER_ID_FK);
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String commentsSelectQuery = String.format("SELECT * FROM %s %s %s WHERE %s = ?",
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TABLE_POST_COMMENTS, commentJoin, commentUserJoin, KEY_POST_COMMENT_POST_ID_FK);
278+
279+
SQLiteDatabase db = this.getReadableDatabase();
280+
Cursor postsCursor = db.rawQuery(postsSelectQuery, null);
281+
282+
try {
283+
if (postsCursor.moveToFirst()) {
284+
do {
285+
InstagramPost post = new InstagramPost();
286+
post.mediaId = postsCursor.getString(postsCursor.getColumnIndexOrThrow(KEY_POST_MEDIA_ID));
287+
post.caption = postsCursor.getString(postsCursor.getColumnIndexOrThrow(KEY_POST_CAPTION));
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post.likesCount = postsCursor.getInt(postsCursor.getColumnIndexOrThrow(KEY_POST_LIKES_COUNT));
289+
post.commentsCount = postsCursor.getInt(postsCursor.getColumnIndexOrThrow(KEY_POST_COMMENTS_COUNT));
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post.createdTime = postsCursor.getLong(postsCursor.getColumnIndexOrThrow(KEY_POST_CREATED_TIME));
291+
292+
InstagramUser user = new InstagramUser();
293+
user.userName = postsCursor.getString(postsCursor.getColumnIndexOrThrow(KEY_USER_NAME));
294+
user.profilePictureUrl = postsCursor.getString(postsCursor.getColumnIndexOrThrow(KEY_USER_PROFILE_PICTURE_URL));
295+
post.user = user;
296+
297+
InstagramImage image = new InstagramImage();
298+
image.imageUrl = postsCursor.getString(postsCursor.getColumnIndexOrThrow(KEY_IMAGE_URL));
299+
image.imageHeight = postsCursor.getInt(postsCursor.getColumnIndexOrThrow(KEY_IMAGE_HEIGHT));
300+
image.imageWidth = postsCursor.getInt(postsCursor.getColumnIndexOrThrow(KEY_IMAGE_WIDTH));
301+
post.image = image;
302+
303+
int key = postsCursor.getInt(0);
304+
305+
// Get all comments for this post
306+
Cursor commentsCursor = db.rawQuery(commentsSelectQuery, new String[]{String.valueOf(key)});
307+
try {
308+
if (commentsCursor.moveToFirst()) {
309+
do {
310+
InstagramComment comment = new InstagramComment();
311+
comment.text = commentsCursor.getString(commentsCursor.getColumnIndexOrThrow(KEY_COMMENT_TEXT));
312+
comment.createdTime = commentsCursor.getLong(commentsCursor.getColumnIndexOrThrow(KEY_COMMENT_CREATED_TIME));
313+
314+
InstagramUser commentUser = new InstagramUser();
315+
commentUser.userName = commentsCursor.getString(commentsCursor.getColumnIndexOrThrow(KEY_USER_NAME));
316+
commentUser.profilePictureUrl = commentsCursor.getString(commentsCursor.getColumnIndexOrThrow(KEY_USER_PROFILE_PICTURE_URL));
317+
comment.user = commentUser;
318+
319+
post.appendComment(comment);
320+
} while (commentsCursor.moveToNext());
321+
}
322+
} catch (Exception e) {
323+
Log.wtf(TAG, "Error while trying to get comments from database");
324+
e.printStackTrace();
325+
} finally {
326+
commentsCursor.close();
327+
}
328+
posts.add(post);
329+
} while (postsCursor.moveToNext());
330+
}
331+
} catch (Exception e) {
332+
Log.wtf(TAG, "Error while trying to get posts from database");
333+
e.printStackTrace();
334+
} finally {
335+
closeCursor(postsCursor);
336+
}
337+
338+
return posts;
339+
}
46340

47-
// ... add code ...
341+
private void closeCursor(Cursor cursor) {
342+
if (cursor != null && !cursor.isClosed()) {
343+
cursor.close();
344+
}
345+
}
48346
}

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