android使用sqlite进行增删改查
时间: 2023-07-11 16:09:10 浏览: 56
好的,下面是基本的 Android SQLite 增删改查操作示例:
1. 导入 SQLiteOpenHelper 类
```
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.content.Context;
```
2. 继承 SQLiteOpenHelper 类
```
public class DatabaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "my_database";
private static final int DATABASE_VERSION = 1;
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
// 创建数据库表
db.execSQL("CREATE TABLE contacts (_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, phone TEXT);");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// 更新数据库表
db.execSQL("DROP TABLE IF EXISTS contacts;");
onCreate(db);
}
}
```
3. 创建 DatabaseHelper 对象
```
DatabaseHelper dbHelper = new DatabaseHelper(context);
```
4. 获取 SQLiteDatabase 对象
```
SQLiteDatabase db = dbHelper.getWritableDatabase();
```
5. 插入数据
```
ContentValues values = new ContentValues();
values.put("name", "John");
values.put("phone", "123456789");
db.insert("contacts", null, values);
```
6. 查询数据
```
Cursor cursor = db.query("contacts", new String[] { "_id", "name", "phone" }, null, null, null, null, null);
if (cursor.moveToFirst()) {
do {
int id = cursor.getInt(cursor.getColumnIndex("_id"));
String name = cursor.getString(cursor.getColumnIndex("name"));
String phone = cursor.getString(cursor.getColumnIndex("phone"));
Log.d("Database", "id: " + id + ", name: " + name + ", phone: " + phone);
} while (cursor.moveToNext());
}
cursor.close();
```
7. 更新数据
```
ContentValues values = new ContentValues();
values.put("phone", "987654321");
db.update("contacts", values, "name=?", new String[] { "John" });
```
8. 删除数据
```
db.delete("contacts", "name=?", new String[] { "John" });
```
以上就是基本的 Android SQLite 增删改查操作示例,需要注意的是,在实际使用中,需要根据业务需求进行相应的修改和优化。