android-sqlite

问题 I am trying to change the position of the RecyclerView this take changes but if I go to another Activity or exit the app and again open it, it tells me the right position. The data are saved to an DB SDQLite and with Adapter I read from there and show to a Fragment . onMove I have write a Log and it says the correct which position was and which is new. At the Log the arrayList = getSampleData() it is working it saves always the position and read the actual position but the ArrayList at

问题 I find the issue when my device is under 4.4.4 , i can't get it why the issue will happen like this. I try to find some solution Why does SQLite say that instr doesnt exist? , so i guess there was no INSTR before when android device version is under 4.4.4 In my case i use the sql like this: //Sort date : Latest to Old date public List<Contact> sortingDate() { List<Contact> contactList = new ArrayList<>(); SQLiteDatabase db = this.getWritableDatabase(); Cursor cursor = db.rawQuery("SELECT *

问题 I want to get records out of sqlite database according to hours. following are my questions 1) I have to extract all data from sqlite for past one hour. I have tried following query but it provide me data for all the hours in present day Query: SELECT * FROM Table1 where Date >= datetime('now','-1 hours') Where Table1 is my table name and Date is coloumn name of type DATETIME Eg: there are following record in database When I fire query in sqlite firefox browser tool it returns me which I do

问题 I'am getting data from the server as a JSONObject and am saving to my table. I'am facing the following error. 11-22 02:18:35.489: E/AndroidRuntime(2597): android.database.sqlite.SQLiteException: near "null": syntax error (code 1): , while compiling: create table Conntact (null INTEGER PRIMARY KEY AUTOINCREMENT, null TEXT, null TEXT, null TEXT, null TEXT, null TEXT, null TEXT); for(int i=0;i<contactdata.length();i++) { JSONObject cont = contactdata.getJSONObject(i); String con_id = getValue

问题 I am new to android programming and 've not thoroughly studied java before . I am really confused on how to use synchronized to ensure thread safety on static variables : I usually create a class named Utils which has some static functions which are most of the time needed by all my other classes. Is this the correct way of keeping repetitive code out of my classes. I always suffer from a problem with using Databases. When I create sqliteHelper class for certain Database and try to manage

问题 SQL Noob here. I am designing a GPS-tracker application and have two tables; a track descriptor table and a track data table. The track descriptor table has the primary key (autoincrement) and the track data table has the foreign key. I would like that after I delete a row from descriptor table, all keys greater than that key are decremented by 1 (does autoincrement do this?). I would also like the same thing to happen in the data table, where all keys greater than deleted are decremented. I

问题 I'm getting no such column exception when creating database to save title, content & sort it by date descending order, i've checked many times and unable to know the reason. My code is public void onCreate(SQLiteDatabase sqLiteDatabase) { //create our table String CREATE_WISHES_TABLE = "CREATE TABLE " + Constants.TABLE_NAME + "(" + Constants.KEY_ID + " INTEGER PRIMARY KEY, " + Constants.TITLE_NAME + " TEXT, " + Constants.CONTENT_NAME + " TEXT, " + Constants.DATE_NAME + " LONG);";

问题 Is performance in android degrading when interacting with a database storage often? Is it better to load objects from DB and pass them around or access database frequently to get the objects? I was thinking if the accessing the DB had more overhead due to instantiating objects from the result set each time. 回答1: I was thinking if the accessing the DB had more overhead due to instantiating objects from the result set each time. Yes, it does, which is why if you are worried about performance,

问题 How to encrypt sqlite database in android with sqlchipher while using greenDao orm. I have searched this many time in SO , but didn't find any working solution . 回答1: In your greendao generator module add this dependency compile 'org.greenrobot:greendao-generator-encryption:2.2.0' So the build.gradle file your generator module will look like this apply plugin: 'java' dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) compile 'org.greenrobot:greendao-generator-encryption:2.2.0' }

问题 here is colums in my table Song song = new Song(); song.setMsong_id(cursor.getLong(0)); song.setmSong_name(cursor.getString(1)); song.setmSong_year(cursor.getLong(2)); song.setmSong_path(cursor.getString(3)); now i want to see the 3rd column so should i write this code song.setmSong_name(cursor.getString(0)); or song.setmSong_name(cursor.getString(3)); with getString(0); it is returning the the size of list as this method private Song cursorToSelectSong(Cursor cursor) { Song song = new Song()