太原阿里云代理商：android sqlite数据库 demo

在Android应用中使用SQLite数据库是一种常见的数据存储方式，下面是一个简单的demo演示如何在Android应用中使用SQLite数据库：

1. 创建数据库帮助类 DBHelper:

public class DBHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "demo.db";
    private static final int DATABASE_VERSION = 1;
    private static final String TABLE_NAME = "users";
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_NAME = "name";

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        String createTable = "CREATE TABLE " + TABLE_NAME + " (" +
                COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                COLUMN_NAME + " TEXT)";
        db.execSQL(createTable);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }

    public void addUser(String name) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(COLUMN_NAME, name);
        db.insert(TABLE_NAME, null, values);
        db.close();
    }

    public ArrayList<String> getAllUsers() {
        ArrayList<String> usersList = new ArrayList<>();
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_NAME, null);
        if (cursor.moveToFirst()) {
            do {
                String name = cursor.getString(cursor.getColumnIndex(COLUMN_NAME));
                usersList.add(name);
            } while (cursor.moveToNext());
        }
        cursor.close();
        db.close();
        return usersList;
    }
}

2. 在MainActivity中使用数据库帮助类：

public class MainActivity extends AppCompatActivity {
    private EditText etName;
    private Button btnAddUser, btnShowUsers;
    private ListView lvUsers;
    private DBHelper dbHelper;

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

        dbHelper = new DBHelper(this);
        etName = findViewById(R.id.et_name);
        btnAddUser = findViewById(R.id.btn_add_user);
        btnShowUsers = findViewById(R.id.btn_show_users);
        lvUsers = findViewById(R.id.lv_users);

        btnAddUser.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String name = etName.getText().toString();
                dbHelper.addUser(name);
                Toast.makeText(MainActivity.this, "User added successfully", Toast.LENGTH_SHORT).show();
            }
        });

        btnShowUsers.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ArrayList<String> usersList = dbHelper.getAllUsers();
                ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, usersList);
                lvUsers.setAdapter(adapter);
            }
        });
    }
}

3. 在布局文件 activity_main.xml 中添加以下代码：

<EditText
    android:id="@+id/et_name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>

<Button
    android:id="@+id/btn_add_user"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Add User"/>

<Button
    android:id="@+id/btn_show_users"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Show Users"/>

<ListView
    android:id="@+id/lv_users"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>

这样就可以在Android应用中使用SQLite数据库对用户信息进行增删改查操作了。希望以上内容对您有所帮助。

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

public class DatabaseHelper extends SQLiteOpenHelper {

private static final String DATABASE_NAME = "demo.db";
private static final String TABLE_NAME = "demo_table";
private static final String COL_ID = "id";
private static final String COL_NAME = "name";
private static final int DATABASE_VERSION = 1;

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

@Override
public void onCreate(SQLiteDatabase db) {
    String createTable = "CREATE TABLE " + TABLE_NAME + "(" +
            COL_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
            COL_NAME + " TEXT)";
    db.execSQL(createTable);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
    onCreate(db);
}

public boolean insertData(String name) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(COL_NAME, name);
    long result = db.insert(TABLE_NAME, null, contentValues);
    return result != -1;
}

public Cursor getAllData() {
    SQLiteDatabase db = this.getWritableDatabase();
    return db.rawQuery("SELECT * FROM " + TABLE_NAME, null);
}

public boolean updateData(String id, String name) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(COL_ID, id);
    contentValues.put(COL_NAME, name);
    db.update(TABLE_NAME, contentValues, "ID = ?", new String[]{id});
    return true;
}

public Integer deleteData(String id) {
    SQLiteDatabase db = this.getWritableDatabase();
    return db.delete(TABLE_NAME, "ID = ?", new String[]{id});
}

}