如何将列表视图数据传递到SQLite数据库？

Question

I'm building message app and my message and number are showing in list-view but I'm not sure how to pass the list-view data to SQLite database? This is my list view code looks like but not sure how to pass the data to database.

package com.example.sunny.messager;

import java.util.ArrayList;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.database.Cursor;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListView;


public class ListActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list);

        ListView lv=(ListView)findViewById(R.id.SmsList);

        if(fetchInbox()!=null){
            ArrayAdapter<String> adapter=new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,fetchInbox());
            lv.setAdapter(adapter);
        }

    }
    public ArrayList<String> fetchInbox(){

        ArrayList<String> sms=new ArrayList<String>();

        Uri uriSms=Uri.parse("content://sms/");

        Cursor cursor=getContentResolver().query(uriSms, new String[]{"_id","address","date","body"}, null, null, null);
        cursor.moveToFirst();
        while(cursor.moveToNext()){

            String address=cursor.getString(1);
            String body=cursor.getString(3);

            sms.add("Number: " +address+"\n Message: " +body);
        }
        return sms;
    }
}

Answer 1

You need to use these classes SQLiteDatabase and and SQLiteOpenHelper.

• SQLiteDatabase is the class for us to perform CRUD function.
• SQLiteOpenHelper is a helper class to manage database creation and version management.

Now let's start code on table structure portion first – create table in Android. We will create a file name SMSData.java , and the code in this file will look like this

package com.example.sqlitedb;
public class SMSData {
    // Labels table name
    public static final String TABLE = "SMSData";

    // Labels Table Columns names
    public static final String KEY_ID = "id";
    public static final String KEY_number = "number";
    public static final String KEY_message= "message";

    // property help us to keep data
    public int SMSData_ID;
    public int number;
    public String message;
}

We'll create a class and name it DBHelper.java and code in this file will look like this, to ease on understand code line by line i put comment in code.

package com.example.sqlitedb;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DBHelper  extends SQLiteOpenHelper {
    //version number to upgrade database version
    //each time if you Add, Edit table, you need to change the
    //version number.
    private static final int DATABASE_VERSION = 4;

    // Database Name
    private static final String DATABASE_NAME = "crud.db";

    public DBHelper(Context context ) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        //All necessary tables you like to create will create here

        String CREATE_TABLE_SMSDATA= "CREATE TABLE " + SMSData.TABLE  + "("
                + SMSData.KEY_ID  + " INTEGER PRIMARY KEY AUTOINCREMENT ,"
                + SMSData.KEY_number+ " INTEGER, "
                + SMSData.KEY_message+ " TEXT )";

        db.execSQL(CREATE_TABLE_SMSDATA);

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Drop older table if existed, all data will be gone!!!
        db.execSQL("DROP TABLE IF EXISTS " + SMSData.TABLE);

        // Create tables again
        onCreate(db);

    } 

}

With above 2 steps, SMSData table will be created when app get started and now we could code the CRUD functions! Create SMSDataRepo.java, the purpose of this class is to perform CRUD on the SMSData table. The code in this file will look like this.

package com.example.sqlitedb;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import java.util.ArrayList;
import java.util.HashMap;

public class SMSDataRepo {
    private DBHelper dbHelper;

    public SMSDataRepo(Context context) {
        dbHelper = new DBHelper(context);
    }

    public int insert(SMSData sMSData) {

        //Open connection to write data
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(SMSData.KEY_number, sMSData.number);
        values.put(SMSData.KEY_message,sMSData.message);

        // Inserting Row
        long SMSData_Id = db.insert(SMSData.TABLE, null, values);
        db.close(); // Closing database connection
        return (int) SMSData_Id;
    }

    public void delete(int SMSData_Id) {

        SQLiteDatabase db = dbHelper.getWritableDatabase();
        // It's a good practice to use parameter ?, instead of concatenate string
        db.delete(SMSData.TABLE, SMSData.KEY_ID + "= ?", new String[] { String.valueOf(SMSData_Id) });
        db.close(); // Closing database connection
    }

    public void update(SMSData sMSData) {

        SQLiteDatabase db = dbHelper.getWritableDatabase();
        ContentValues values = new ContentValues();

        values.put(SMSData.KEY_number, sMSData.number);
        values.put(SMSData.KEY_message,sMSData.message);

        // It's a good practice to use parameter ?, instead of concatenate string
        db.update(SMSData.TABLE, values, SMSData.KEY_ID + "= ?", new String[] { String.valueOf(SMSData.SMSData_ID) });
        db.close(); // Closing database connection
    }

    public ArrayList<HashMap<String, String>>  getSMSDataList() {
        //Open connection to read only
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String selectQuery =  "SELECT  " +
                SMSData.KEY_ID + "," +
                SMSData.KEY_number+                     
                SMSData.KEY_message+ "," +
                " FROM " + SMSData.TABLE;

        //SMSData sMSData= new SMSData();
        ArrayList<HashMap<String, String>> sMSDataList = new ArrayList<HashMap<String, String>>();

        Cursor cursor = db.rawQuery(selectQuery, null);
        // looping through all rows and adding to list

        if (cursor.moveToFirst()) {
            do {
                HashMap<String, String> sMSData= new HashMap<String, String>();
                sMSData.put("number", cursor.getString(cursor.getColumnIndex(SMSData.KEY_number)));
                sMSData.put("message", cursor.getString(cursor.getColumnIndex(SMSData.KEY_message)));
                sMSDataList.add(sMSData);

            } while (cursor.moveToNext());
        }

        cursor.close();
        db.close();
        return sMSDataList;

    }

    public SMSData getSMSDataById(int Id){
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String selectQuery =  "SELECT  " +
                SMSData.KEY_ID + "," +
                SMSData.KEY_number + "," +
                SMSData.KEY_message +
                " FROM " + SMSData.TABLE
                + " WHERE " +
                SMSData.KEY_ID + "=?";// It's a good practice to use parameter ?, instead of concatenate string

        int iCount =0;
        SMSData sMSData= new SMSData();

        Cursor cursor = db.rawQuery(selectQuery, new String[] { String.valueOf(Id) } );

        if (cursor.moveToFirst()) {
            do {
                sMSData.SMSData_ID =cursor.getInt(cursor.getColumnIndex(SMSData.KEY_ID));
                sMSData.number=cursor.getInt(cursor.getColumnIndex(SMSData.KEY_number));
                sMSData.message=cursor.getString(cursor.getColumnIndex(SMSData.KEY_message));

            } while (cursor.moveToNext());
        }

        cursor.close();
        db.close();
        return sMSData;
    }

}