android-sqlite

问题 hello all i am developing an android application which listen to incoming whatsapp notification and show it in listView using NotificationListenerService . i need help in sqlite database to store notifications and retrieve data and show in listView. data is one Bitmap image and text string... following is code am trying.. databaseHandler public class DatabaseHandler extends SQLiteOpenHelper{ // Database Version private static final int DATABASE_VERSION = 1; // Database Name private static

问题 I fairly new to the whole SQLite android implementation and I am clueless on what to do to get rid of this error. Essentially what I am trying to do with my database is save user data (9 Array lists with a maximum of 20 elements in each of them). I have an app where users can plot points on a map and make a "Road Trip". They then have a choice to save that road trip. I am saving each road trip as a table and grabbing the information needed. Here is my code. I am trying to call the method

问题 At our company, we are currently evaluating switching to Room for managing our mobile devices databases. The main reasons we want to do that is because of inheritance support and increased testability. Currently, we are using GreenDao to access an internal database (on which the session data, settings, user data and similar things are stored) and to access our external databases (sqlites that we retrieve from an FTP-Server and store in subfolders in /sdcard/Android/app-folder/ ; these provide

问题 public class MyAct extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); SQLiteDatabase db = openOrCreateDatabase("MyDb",MODE_PRIVATE,null); db.execSQL("CREATE TABLE IF NOT EXISTS MyTab (Month INT(2),Date INT(2),Year INT(4),Event VARCHAR;"); db.execSQL("INSERT INTO MyTab VALUES (0,1,2012,'mini_proj');"); db.close(); } } I have written this small snippet to create a table, but it's not working. What is

问题 I am just wondering, how can I convert from byte array to blob? My database looks like this: Photo id (int) | image_key (blob) This is my code: //this for getting data from picture Bitmap yourImage = extras.getParcelable("data"); // convert bitmap to byte ByteArrayOutputStream stream = new ByteArrayOutputStream(); yourImage.compress(Bitmap.CompressFormat.PNG, 100, stream); //the problem is right here, i want to convert this byte array, to a blob data type byte imageInByte[] = stream

问题 I have a composite primary key {shop_id, product_id} for SQLite Now, I want an auto-increment value for product_id which resets to 1 if shop id is changed. Basically, I want auto-generated composite key e.g. Shop ID Product Id 1 1 1 2 1 3 2 1 2 2 3 1 Can I achieve this with auto-increment? How? 回答1: Normal Sqlite tables are B*-trees that use a 64-bit integer as their key. This is called the rowid. When inserting a row, if a value is not explicitly given for this, one is generated. An INTEGER

问题 I have a table as follows: CREATE TABLE [TBL_test] ([ID] int PRIMARY KEY,[RDate] CHAR(10),[Debtor] int, [Creditor] int); insert into [TBL_test] values(1,'2012/10/11',100,0); **insert into [TBL_test] values(2,'2012/11/02',20,0);** insert into [TBL_test] values(3,'2012/11/09',0,5); **insert into [TBL_test] values(4,'2012/11/02',0,10);** select *,(select sum(t2.Debtor - t2.Creditor) from TBL_test t2 where t2.rdate <= t1.rdate order by rdate) as RT from TBL_test t1 order by rdate Result ID RDate

问题 I'm planning the database for my app. I would like to allow others to use my data. However, I only want them to access a couple tables. Is it possible to only allow other apps to access certain tables? Having all my db code in one place (content provider) just seems like a good idea, rather than having to split it up. What would be considered best practice? 回答1: In your Android Manifest file you should for your content provider tag set an attribute grandUriPermissions to false . Thus, you

问题 I am trying to use the following query as part of a larger query in my Android SQLite datbase, but it seems to me that the errors I'm receiving point to Android SQLite not supporting the lead() function yet. I've tried looking through the release log on sqlite.org and was unable to find when support for window functions like lead() were added. I've also been unable to find any other source for this particular information. My query: ... SELECT * , CASE WHEN WorkTypeID != 1 THEN lead

问题 My Query is SELECT DefaultId FROM tblsample where ('567' = DefaultId) || ('567' = Name) In the above query table name = tblsample Column Names = DefaultId , Name Input Value = 567 Now i want to check this value is available in which column from the table and return its DefaultId . I am able to achieve this in Sqlite, want to know is there still better way to optimize the query and In android using database.query(boolean distinct, String table, String[] columns,String selection, String[]