SqlLite

Manipulation d’une base de données :

Utilisez SQLite Data Browser http://sqlitebrowser.org/

Pour les manipulations : http://zetcode.com/db/sqlite/datamanipulation/

Exemples : 

select * from nameday where mois=3 and jour=2 and pays= »FR »

update nameday SET  prenoms= »Charles Le Bon » where mois=3 and jour=2 and pays= »FR »

Utilisation d’une base de données déjà créée :
1) Modify your database schema/structure to make it compatible with Android OS :
Change primary key fields of all tables to “_id“.
2) Create a table “android_metadata(…)” and insert one row :
CREATE TABLE “android_metadata” (“locale” TEXT DEFAULT ‘en_US’) and INSERT INTO “android_metadata” VALUES (‘en_US’)
3) Copy your database file to … yourapp/assets/
4) Read this file from MyDatabaseHelper and write it to application’s database directory
5) Open and Read your database from your application using MyDatabaseHelper extends SQLiteOpenHelper
6) Query on that database

http://zaman91.wordpress.com/2010/09/22/android-how-to-use-own-sqlite-database/

http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/

Ou création via SQL : http://www.michenux.net/android-database-sqlite-creation-upgrade-245.html

Suppression de ligne :

   public static int deleteContact(SQLiteDatabase db, String sNom) {  
     //on delete la ligne concernée  
     //retourne 1 si ok 0 sinon  
     //db.delete("tablename","id=? and name=?",new String[]{"1","jack"});  
     //delete from tablename where id='1' and name ='jack'"  
     int nRes;  
     nRes=db.delete("contact", "nom=?", new String[]{sNom});  
     Log.d("delete"," "+nRes);  
     return nRes;  
   }  

Création de la base avec une table :

 public class DbHelper extends SQLiteOpenHelper {  
   private static final String DATABASE_NAME = "dbnumtel.db";  
   private static final int DATABASE_VERSION = 1;  
   public DbHelper(Context context) {  
     super(context, DATABASE_NAME, null, DATABASE_VERSION);  
   }  
   @Override  
   public void onCreate(SQLiteDatabase db) {  
     db.execSQL("CREATE TABLE IF NOT EXISTS contact ( " +  
         "_id INTEGER PRIMARY KEY AUTOINCREMENT," +  
         "nom TEXT," +  
         "numtel TEXT," +  
         "normtel TEXT," +  
         "logtel INTEGER," +  
         "idico INTEGER)");  
   }  
 }  

Opérations diverses :

  public static long CompteEnr(SQLiteDatabase db) {  
     Log.d("Base", "Nb enr=" + String.valueOf(DatabaseUtils.queryNumEntries(db, "contact")));  
     return DatabaseUtils.queryNumEntries(db, "contact");  
   }  
   public static void onDelete(SQLiteDatabase db) {  
     db.execSQL("DELETE FROM contact");  
   }  
   public static boolean onRecherche(SQLiteDatabase db, String sNum) {  
     Cursor c = db.query("contact", null,  
         "numtel = '" + sNum + "'", null, null, null, null);  
     //si aucun élément n'a été retourné dans la requête, on renvoie faux  
     if (c.getCount() == 0) {  
       c.close();  
       return false;  
     } else {  
       c.close();  
       return true;  
     }  
   }  

 

Pour ajouter la base de données (cf ce post) :

 import java.io.File;  
 import java.io.FileOutputStream;  
 import java.io.IOException;  
 import java.io.InputStream;  
 import java.io.OutputStream;  
 import android.content.Context;  
 import android.database.Cursor;  
 import android.database.SQLException;  
 import android.database.sqlite.SQLiteDatabase;  
 import android.database.sqlite.SQLiteOpenHelper;  
 public class DataBaseHelperClass extends SQLiteOpenHelper{  
  //The Android's default system path of your application database.  
 private static String DB_PATH = "/data/data/package_name/databases/";  
 // Data Base Name.  
 private static final String DATABASE_NAME = "DBName.sqlite";  
 // Data Base Version.  
 private static final int DATABASE_VERSION = 1;  
 // Table Names of Data Base.  
 static final String TABLE_Name = "tableName";  
 public Context context;  
 static SQLiteDatabase sqliteDataBase;  
 /**  
  * Constructor  
  * Takes and keeps a reference of the passed context in order to access to the application assets and resources.  
  * @param context  
  * Parameters of super() are  1. Context  
  *               2. Data Base Name.  
  *               3. Cursor Factory.  
  *               4. Data Base Version.  
  */  
 public DataBaseHelperClass(Context context) {      
   super(context, DATABASE_NAME, null ,DATABASE_VERSION);  
   this.context = context;  
 }  
 /**  
  * Creates a empty database on the system and rewrites it with your own database.  
  * By calling this method and empty database will be created into the default system path  
  * of your application so we are gonna be able to overwrite that database with our database.  
  * */  
 public void createDataBase() throws IOException{  
   //check if the database exists  
   boolean databaseExist = checkDataBase();  
   if(databaseExist){  
     // Do Nothing.  
   }else{  
     this.getWritableDatabase();       
     copyDataBase();   
   }// end if else dbExist  
 } // end createDataBase().  
 /**  
  * Check if the database already exist to avoid re-copying the file each time you open the application.  
  * @return true if it exists, false if it doesn't  
  */  
 public boolean checkDataBase(){  
   File databaseFile = new File(DB_PATH + DATABASE_NAME);  
   return databaseFile.exists();      
 }  
 /**  
  * Copies your database from your local assets-folder to the just created empty database in the  
  * system folder, from where it can be accessed and handled.  
  * This is done by transferring byte stream.  
  * */  
 private void copyDataBase() throws IOException{   
   //Open your local db as the input stream  
   InputStream myInput = context.getAssets().open(DATABASE_NAME);   
   // Path to the just created empty db  
   String outFileName = DB_PATH + DATABASE_NAME;   
   //Open the empty db as the output stream  
   OutputStream myOutput = new FileOutputStream(outFileName);   
   //transfer bytes from the input file to the output file  
   byte[] buffer = new byte[1024];  
   int length;  
   while ((length = myInput.read(buffer))>0){  
     myOutput.write(buffer, 0, length);  
   }  
   //Close the streams  
   myOutput.flush();  
   myOutput.close();  
   myInput.close();   
 }  
 /**  
  * This method opens the data base connection.  
  * First it create the path up till data base of the device.  
  * Then create connection with data base.  
  */  
 public void openDataBase() throws SQLException{     
   //Open the database  
   String myPath = DB_PATH + DATABASE_NAME;  
   sqliteDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);   
 }  
 /**  
  * This Method is used to close the data base connection.  
  */  
 @Override  
 public synchronized void close() {   
   if(sqliteDataBase != null)  
     sqliteDataBase.close();   
   super.close();   
 }  
 /**  
 * Apply your methods and class to fetch data using raw or queries on data base using   
 * following demo example code as:  
 */  
 public String getUserNameFromDB(){  
   String query = "select User_First_Name From "+TABLE_USER_DETAILS;  
   Cursor cursor = sqliteDataBase.rawQuery(query, null);  
   String userName = null;  
   if(cursor.getCount()>0){  
     if(cursor.moveToFirst()){  
   do{  
         userName = cursor.getString(0);  
       }while (cursor.moveToNext());  
     }  
   }  
   return userName;  
 }  
 @Override  
 public void onCreate(SQLiteDatabase db) {  
   // No need to write the create table query.  
   // As we are using Pre built data base.  
   // Which is ReadOnly.  
 }  
 @Override  
 public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {  
   // No need to write the update table query.  
   // As we are using Pre built data base.  
   // Which is ReadOnly.  
   // We should not update it as requirements of application.  
 }    
 }  

 

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