When android was packaged and installed, it added external database. I had this requirement, so I wrote the following code, which I will share with you now

public void createDatabase() {
  try 
  {  
   //  To obtain .db The absolute path to the file   
   String databaseFilename = DATABASE_PATH + DATABASE_FILENAME;  
   File dir = new File(rootDirectory);  
   //  If the directory does not exist, create it   
   if (!dir.exists())  
    dir.mkdir();  
   //  If the /data/data/org.itec.android.Classroom
   // Does not exist in the directory  .db File from res\raw Copy this file into the directory   
   if (!(new File(databaseFilename)).exists()){  
    //  For packaging .db Of the file InputStream object   
    InputStream is = getResources().openRawResource(R.raw.mydb);  
    FileOutputStream fos = new FileOutputStream(databaseFilename);  
    byte[] buffer = new byte[7168];  
    int count = 0;  
    //  Begin to copy .db file   
    while ((count = is.read(buffer)) > 0){  
     fos.write(buffer, 0, count);  
    }  
    fos.close();  
    is.close();  
   }
  }  
  catch (Exception e){  
  }
 }