SQLLite

1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.example.android.notepad;
18
19import com.example.android.notepad.NotePad.Notes;
20
21import android.content.ContentProvider;
22import android.content.ContentUris;
23import android.content.ContentValues;
24import android.content.Context;
25import android.content.UriMatcher;
26import android.content.res.Resources;
27import android.database.Cursor;
28import android.database.SQLException;
29import android.database.sqlite.SQLiteDatabase;
30import android.database.sqlite.SQLiteOpenHelper;
31import android.database.sqlite.SQLiteQueryBuilder;
32import android.net.Uri;
33import android.text.TextUtils;
34import android.util.Log;
35
36import java.util.HashMap;
37
38/**
39 * Provides access to a database of notes. Each note has a title, the note
40 * itself, a creation date and a modified data.
41 */
42public class NotePadProvider extends ContentProvider {
43
44 private static final String TAG = "NotePadProvider";
45
46 private static final String DATABASE_NAME = "note_pad.db";
47 private static final int DATABASE_VERSION = 2;
48 private static final String NOTES_TABLE_NAME = "notes";
49
50 private static HashMap<String, String> sNotesProjectionMap;
51
52 private static final int NOTES = 1;
53 private static final int NOTE_ID = 2;
54
55 private static final UriMatcher sUriMatcher;
56
57 /**
58 * This class helps open, create, and upgrade the database file.
59 */
60 private static class DatabaseHelper extends SQLiteOpenHelper {
61
62 DatabaseHelper(Context context) {
63 super(context, DATABASE_NAME, null, DATABASE_VERSION);
64 }
65
66 @Override
67 public void onCreate(SQLiteDatabase db) {
68 db.execSQL("CREATE TABLE " + NOTES_TABLE_NAME + " ("
69 + Notes._ID + " INTEGER PRIMARY KEY,"
70 + Notes.TITLE + " TEXT,"
71 + Notes.NOTE + " TEXT,"
72 + Notes.CREATED_DATE + " INTEGER,"
73 + Notes.MODIFIED_DATE + " INTEGER"
74 + ");");
75 }
76
77 @Override
78 public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
79 Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
80 + newVersion + ", which will destroy all old data");
81 db.execSQL("DROP TABLE IF EXISTS notes");
82 onCreate(db);
83 }
84 }
85
86 private DatabaseHelper mOpenHelper;
87
88 @Override
89 public boolean onCreate() {
90 mOpenHelper = new DatabaseHelper(getContext());
91 return true;
92 }
93
94 @Override
95 public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
96 String sortOrder) {
97 SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
98
99 switch (sUriMatcher.match(uri)) {
100 case NOTES:
101 qb.setTables(NOTES_TABLE_NAME);
102 qb.setProjectionMap(sNotesProjectionMap);
103 break;
104
105 case NOTE_ID:
106 qb.setTables(NOTES_TABLE_NAME);
107 qb.setProjectionMap(sNotesProjectionMap);
108 qb.appendWhere(Notes._ID + "=" + uri.getPathSegments().get(1));
109 break;
110
111 default:
112 throw new IllegalArgumentException("Unknown URI " + uri);
113 }
114
115 // If no sort order is specified use the default
116 String orderBy;
117 if (TextUtils.isEmpty(sortOrder)) {
118 orderBy = NotePad.Notes.DEFAULT_SORT_ORDER;
119 } else {
120 orderBy = sortOrder;
121 }
122
123 // Get the database and run the query
124 SQLiteDatabase db = mOpenHelper.getReadableDatabase();
125 Cursor c = qb.query(db, projection, selection, selectionArgs, null, null, orderBy);
126
127 // Tell the cursor what uri to watch, so it knows when its source data changes
128 c.setNotificationUri(getContext().getContentResolver(), uri);
129 return c;
130 }
131
132 @Override
133 public String getType(Uri uri) {
134 switch (sUriMatcher.match(uri)) {
135 case NOTES:
136 return Notes.CONTENT_TYPE;
137
138 case NOTE_ID:
139 return Notes.CONTENT_ITEM_TYPE;
140
141 default:
142 throw new IllegalArgumentException("Unknown URI " + uri);
143 }
144 }
145
146 @Override
147 public Uri insert(Uri uri, ContentValues initialValues) {
148 // Validate the requested uri
149 if (sUriMatcher.match(uri) != NOTES) {
150 throw new IllegalArgumentException("Unknown URI " + uri);
151 }
152
153 ContentValues values;
154 if (initialValues != null) {
155 values = new ContentValues(initialValues);
156 } else {
157 values = new ContentValues();
158 }
159
160 Long now = Long.valueOf(System.currentTimeMillis());
161
162 // Make sure that the fields are all set
163 if (values.containsKey(NotePad.Notes.CREATED_DATE) == false) {
164 values.put(NotePad.Notes.CREATED_DATE, now);
165 }
166
167 if (values.containsKey(NotePad.Notes.MODIFIED_DATE) == false) {
168 values.put(NotePad.Notes.MODIFIED_DATE, now);
169 }
170
171 if (values.containsKey(NotePad.Notes.TITLE) == false) {
172 Resources r = Resources.getSystem();
173 values.put(NotePad.Notes.TITLE, r.getString(android.R.string.untitled));
174 }
175
176 if (values.containsKey(NotePad.Notes.NOTE) == false) {
177 values.put(NotePad.Notes.NOTE, "");
178 }
179
180 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
181 long rowId = db.insert(NOTES_TABLE_NAME, Notes.NOTE, values);
182 if (rowId > 0) {
183 Uri noteUri = ContentUris.withAppendedId(NotePad.Notes.CONTENT_URI, rowId);
184 getContext().getContentResolver().notifyChange(noteUri, null);
185 return noteUri;
186 }
187
188 throw new SQLException("Failed to insert row into " + uri);
189 }
190
191 @Override
192 public int delete(Uri uri, String where, String[] whereArgs) {
193 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
194 int count;
195 switch (sUriMatcher.match(uri)) {
196 case NOTES:
197 count = db.delete(NOTES_TABLE_NAME, where, whereArgs);
198 break;
199
200 case NOTE_ID:
201 String noteId = uri.getPathSegments().get(1);
202 count = db.delete(NOTES_TABLE_NAME, Notes._ID + "=" + noteId
203 + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs);
204 break;
205
206 default:
207 throw new IllegalArgumentException("Unknown URI " + uri);
208 }
209
210 getContext().getContentResolver().notifyChange(uri, null);
211 return count;
212 }
213
214 @Override
215 public int update(Uri uri, ContentValues values, String where, String[] whereArgs) {
216 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
217 int count;
218 switch (sUriMatcher.match(uri)) {
219 case NOTES:
220 count = db.update(NOTES_TABLE_NAME, values, where, whereArgs);
221 break;
222
223 case NOTE_ID:
224 String noteId = uri.getPathSegments().get(1);
225 count = db.update(NOTES_TABLE_NAME, values, Notes._ID + "=" + noteId
226 + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs);
227 break;
228
229 default:
230 throw new IllegalArgumentException("Unknown URI " + uri);
231 }
232
233 getContext().getContentResolver().notifyChange(uri, null);
234 return count;
235 }
236
237 static {
238 sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
239 sUriMatcher.addURI(NotePad.AUTHORITY, "notes", NOTES);
240 sUriMatcher.addURI(NotePad.AUTHORITY, "notes/#", NOTE_ID);
241
242 sNotesProjectionMap = new HashMap<String, String>();
243 sNotesProjectionMap.put(Notes._ID, Notes._ID);
244 sNotesProjectionMap.put(Notes.TITLE, Notes.TITLE);
245 sNotesProjectionMap.put(Notes.NOTE, Notes.NOTE);
246 sNotesProjectionMap.put(Notes.CREATED_DATE, Notes.CREATED_DATE);
247 sNotesProjectionMap.put(Notes.MODIFIED_DATE, Notes.MODIFIED_DATE);
248 }
249}