问题 将您自己的SQLite数据库添加到Android应用程序


我们如何将自己的SQLite数据库添加到android项目?


7007
2018-02-23 04:22


起源

我通常不说RTFM,但是RTFM: developer.android.com/reference/android/database/sqlite/... - Brian Driscoll
这个例子将引起你的兴趣 http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/ - ingsaurabh
这将帮助您创建,插入,删除或中化SQLite数据库。 vogella.de/articles/AndroidSQLite/article.html - Himanshu Dudhat
我认为他正在编制一份清单 how to... 的问题。它本来会更糟;很多人来这里要求你为他们编写代码,比如这个网站是某种基于社区的免费应用创建工具。
通过这个tutroial最好的 codeproject.com/Articles/119293/... - Jabbir Basha


答案:


试试这段代码:

 public class DataBaseHelper extends SQLiteOpenHelper {
     private Context mycontext;

     //private String DB_PATH = mycontext.getApplicationContext().getPackageName()+"/databases/";
     private static String DB_NAME = "(datbasename).sqlite"; //the extension may be .sqlite or .db
     public SQLiteDatabase myDataBase;
     /*private String DB_PATH = "/data/data/"
                             + mycontext.getApplicationContext().getPackageName()
                             + "/databases/";*/

     public DataBaseHelper(Context context) throws IOException {
         super(context, DB_NAME, null, 1);
         this.mycontext = context;
         boolean dbexist = checkdatabase();
         if (dbexist) {
             //System.out.println("Database exists");
             opendatabase();
         } else {
             System.out.println("Database doesn't exist");
             createdatabase();
         }

     }

     public void createdatabase() throws IOException {
         boolean dbexist = checkdatabase();
         if (dbexist) {
             //System.out.println(" Database exists.");
         } else {
             this.getReadableDatabase();
             try {
                 copydatabase();
             } catch (IOException e) {
                 throw new Error("Error copying database");
             }
         }
     }
     private boolean checkdatabase() {
         //SQLiteDatabase checkdb = null;
         boolean checkdb = false;
         try {
             String myPath = DB_PATH + DB_NAME;
             File dbfile = new File(myPath);
             //checkdb = SQLiteDatabase.openDatabase(myPath,null,SQLiteDatabase.OPEN_READWRITE);
             checkdb = dbfile.exists();
         } catch (SQLiteException e) {
             System.out.println("Database doesn't exist");
         }

         return checkdb;
     }
     private void copydatabase() throws IOException {

         //Open your local db as the input stream
         InputStream myinput = mycontext.getAssets().open(DB_NAME);

         // Path to the just created empty db
         String outfilename = DB_PATH + DB_NAME;

         //Open the empty db as the output stream
         OutputStream myoutput = new FileOutputStream("/data/data/(packagename)/databases/(datbasename).sqlite");

         // transfer byte to inputfile to outputfile
         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();

     }

     public void opendatabase() throws SQLException {
         //Open the database
         String mypath = DB_PATH + DB_NAME;
         myDataBase = SQLiteDatabase.openDatabase(mypath, null, SQLiteDatabase.OPEN_READWRITE);

     }



     public synchronized void close() {
         if (myDataBase != null) {
             myDataBase.close();
         }
         super.close();
     }

11
2018-05-10 10:44



这是否可以在无根设备上运行? - gisek
是的,显然,代码适用于所有设备。而且,我也在我的应用程序中使用它只是工作正常:) - Jaydeep Khamar
@JaydeepKhamar:什么是DB_PATH? - Deepzz
Jaydeep Khamar,你能告诉我你上面做的完整例子吗? - Kamal Kumar