android-sqlite

问题 What is a better algorithm on loading or populating images from SD CARD, than storing each image path as Constants? public final class Constants { public static final String[] IMAGES = new String[] { // Heavy images "file:///mnt/sdcard/folder/folder/folder/1.jpg", "file:///mnt/sdcard/folder/folder/folder/2.jpg", "file:///mnt/sdcard/folder/folder/folder/3.jpg", "file:///mnt/sdcard/folder/4.jpg", ); } Basically I am learning the Universal Image Loader, and focusing on the grid view

问题 I have Myactivity which is getting the intent data from the former activity. The intent data is sent through a spinner of the activity. I want to save this intent data of the spinner to the Myactvity. the intent data should persist when i enter the Myactivity through menu option of next activity. 回答1: in your First Activity1 Intent myintent= new Intent(FirstActivity.this,SecondActivity.class); myintent.putExtra("Name", "your String"); startActivity(myintent); in Second Activity2 Intent

问题 Hi i am creating an app which stores the password of the user entering. and whenever he needs to change his password then the data has to be changed. The problem i am facing is while i am calling the DBHelper class (i created to do all my database works) its not deleting the table if it is available. It will be more helpful if someone tells me how to delete the entries in the table while calling the DBHelper class. I realized that the OnCreate and OnUpgrade functions are not executing except

问题 I want to create a dynamic query using room so that in one case the query returns a particular order type and during runtime if the order type changes then a new query is created and the data is returned ordered according to this type. I am returning a DataSource.Factory object using Room. I am using the below statement to process my query:- if(getSortOrderType().equals(context.getString(R.string.sortByPopular))) { dbSortType = "popularity"; } else { dbSortType = "vote_average"; }

问题 Assume we have an Activity with n TextView s that represent one line notes. These notes are stored somewhere (local database, network etc), and each time onResume() being called, the proper number of TextView s are drawn according to that stored data. Now, lets say the user want to delete a note, what would be the best way the resolve the specific TextView , back to its storage entity? At the moment, the only way I know is by using View.Tag , and having some manager to translate it to data

问题 I was wondering in the execSQL method which can take 1 or 2 arguments. Why using the second method, if I can use an object to directly do my operation on an SQLite db? In example: db.execSQL("INSERT INTO "+ TableName +" VALUES (null, ?)", new Object[] { type.getName() }) is this better than using this db.execSQL("INSERT INTO "+ TableName +" VALUES (null,"+ type.getName() +")") is the 1st example more secure? faster when executing? easier to read... or is it the same? 回答1: Method 1 is better.

问题 I'm developing and android application in which I often use access the local database. This database can be accessed from differents therads, so I have a coordination problem for the database. I use the following open() and close() method. public void open(){ mDb=mDbHelper.getWritableDatabase(); } public void close(){ mDb.close(); } So, usually, when I need to access the db for some operations I open the database, then I perform some operation, and finally I close the database. The code I

问题 I have created a very simple database android app. It takes an input and display result. Add button is used to add the input and delete button for deleting the input stored in SQLite database. My cursor in Android SQLite is pointed correctly but still I am facing the error: Caused by: java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it. Following is the cursor part: Cursor c = db.rawQuery

问题 My table structure is like this, using sqlite3 CREATE TABLE enghindi (eng TEXT,hindi TEXT) i have an table named enghindi in that there is two column named hindi , eng , i want to merge eng column's record and also combine hindi word by comma separated look at the below table is looking like i want to do look like this below i want to do this with sqlite3 query 回答1: This should work: SELECT GROUP_CONCAT(eng), hindi FROM enghindi GROUP BY hindi; 来源： https://stackoverflow.com/questions/19332722

问题 Here is the schema: SQL query is: SELECT * from unjdat where col_1 = " myWord "; i.e., I want to display all columns for a row whose col_1 is myWord . int i; String temp; words = new ArrayList<String>(); Cursor wordsCursor = database.rawQuery("select * from unjdat where col_1 = \"apple\" ", null); //myWord is "apple" here if (wordsCursor != null) wordsCursor.moveToFirst(); if (!wordsCursor.isAfterLast()) { do { for (i = 0; i < 11; i++) { temp = wordsCursor.getString(i); words.add(temp); } }