Cómo convertir registros de base de datos en un archivo csv en android?

Question

Hola quiero exportar mis datos de la base de datos en formato CSV para mi aplicación de Android. ¿Cómo puedo hacer esto? Cualquier cuerpo me ayuda? Gracias por adelantado.

Answer 1

Hola hacer como esto ....

package com.my.CSVcreation; 
import java.io.File; 
import java.io.FileWriter; 
import java.io.IOException; 
import android.app.Activity; 
import android.app.ProgressDialog; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.SQLiteDatabase; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.os.Environment; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 
import android.widget.Toast; 

public class CSVCreationActivity extends Activity { 
    TextView empidtxt,empnametxt,empsaltxt; 
    EditText empidet,empnameet,empsalet; 
    Button insetbt,viewbt; 
    SQLiteDatabase myDatabase=null; 
    String DataBase_Name="employeedata"; 
    String Table_Name="employeedetails"; 
    Cursor c1,c2; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 

    empidtxt=(TextView)findViewById(R.id.tv1); 
    empnametxt=(TextView)findViewById(R.id.tv2); 
    empsaltxt=(TextView)findViewById(R.id.tv3); 

    empidet=(EditText)findViewById(R.id.et1); 
    empnameet=(EditText)findViewById(R.id.et2); 
    empsalet=(EditText)findViewById(R.id.et3); 

    insetbt=(Button)findViewById(R.id.bt1); 
    viewbt=(Button)findViewById(R.id.bt2); 

    try { 
     myDatabase=this.openOrCreateDatabase(DataBase_Name, MODE_PRIVATE, null); 
     System.out.println("databse has been creates....."); 
     myDatabase.execSQL("create table if not exists " + Table_Name + "(empid integer(10),empname varchar(50),empsal integer(10))"); 
     System.out.println("table has been created....."); 
     c1 = myDatabase.rawQuery("select * from " + Table_Name, null); 
     c1.moveToFirst(); 
     int count1 = c1.getCount(); 
     System.out.println("columns --->" + count1); 
     if (count1 == 0) { 
      myDatabase.execSQL("insert into "+Table_Name+ "(empid,empname,empsal)" +"values(101,'asha',20000)"); 
      System.out.println("data base has been inserted....."); 
     } 

     c2 = myDatabase.rawQuery("select * from " + Table_Name, null); 
     c2.moveToFirst(); 
     int count2 = c2.getCount(); 
     System.out.println("columns --->" + count2); 
     final int column1 = c2.getColumnIndex("empid"); 
     final int column2 = c2.getColumnIndex("empname"); 
     final int column3 = c2.getColumnIndex("empsal"); 

     insetbt.setOnClickListener(new View.OnClickListener() {    
      @Override 
      public void onClick(View v) { 
       if (c2 != null) { 
        do { 
         int id = c2.getInt(column1); 
         String name = c2.getString(column2); 
         int salary = c2.getInt(column3); 

         System.out.println("empID --> "+id); 
         System.out.println("empNAME --> "+name); 
         System.out.println("empsalalry --> "+salary); 
        } while(c2.moveToNext()); 
       }         
      } 
     }); 

     viewbt.setOnClickListener(new View.OnClickListener() {    
      @Override 
      public void onClick(View v) { 
       try { 
        new ExportDatabaseCSVTask().execute(""); 
       } catch(Exception ex) { 
        Log.e("Error in MainActivity",ex.toString()); 
       } 
      } 
     }); 
    } 
    catch(SQLException ex) { ex.printStackTrace(); } 
    /*finally { 
     if (myDB != null) { myDB.close(); } 
    }*/ 
} 


public class ExportDatabaseCSVTask extends AsyncTask<String, Void, Boolean> { 
    private final ProgressDialog dialog = new ProgressDialog(CSVCreationActivity.this); 

    @Override 
    protected void onPreExecute() { 
     this.dialog.setMessage("Exporting database..."); 
     this.dialog.show(); 
    } 

    protected Boolean doInBackground(final String... args) { 
     File dbFile = getDatabasePath("myDatabase.db"); 
     System.out.println(dbFile); // displays the data base path in your logcat 
     File exportDir = new File(Environment.getExternalStorageDirectory(), ""); 

     if (!exportDir.exists()) { exportDir.mkdirs(); } 

     File file = new File(exportDir, "myfile.csv"); 
     try { 
      file.createNewFile(); 
      CSVWriter csvWrite = new CSVWriter(new FileWriter(file)); 
      Cursor curCSV = myDatabase.rawQuery("select * from " + Table_Name,null); 
      csvWrite.writeNext(curCSV.getColumnNames()); 
      while(curCSV.moveToNext()) { 
       String arrStr[] ={curCSV.getString(0),curCSV.getString(1),curCSV.getString(2)}; 
       // curCSV.getString(3),curCSV.getString(4)}; 
       csvWrite.writeNext(arrStr); 
      } 
      csvWrite.close(); 
      curCSV.close(); 
      return true; 
     } catch(SQLException sqlEx) { 
      Log.e("MainActivity", sqlEx.getMessage(), sqlEx); 
      return false; 
     } catch (IOException e) { 
      Log.e("MainActivity", e.getMessage(), e); 
      return false; 
     } 
    } 

    protected void onPostExecute(final Boolean success) { 
     if (this.dialog.isShowing()) { this.dialog.dismiss(); } 
     if (success) { 
      Toast.makeText(CSVCreationActivity.this, "Export successful!", Toast.LENGTH_SHORT).show(); 
     } else { 
      Toast.makeText(CSVCreationActivity.this, "Export failed", Toast.LENGTH_SHORT).show(); 
     } 
    } 
} 

Y obtendrá CSVReader y el archivo desde el sitio CSVWriter https://code.google.com/p/secrets-for-android/source/checkout siguiente. Todo lo mejor.

No se olvide de añadir el permiso para el archivo de manifiesto <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>