android如何通过插入半字数据库获取某些列的值

// 打开或创建数据库连接
SQLiteDatabase db = openOrCreateDatabase("mydatabase.db", Context.MODE_PRIVATE, null);

// 创建表
db.execSQL("CREATE TABLE IF NOT EXISTS mytable (id INTEGER PRIMARY KEY, name TEXT, age INTEGER)");

// 插入数据
db.execSQL("INSERT INTO mytable (name, age) VALUES ('John', 25)");
db.execSQL("INSERT INTO mytable (name, age) VALUES ('Alice', 30)");

// 查询数据
String[] columns = {"name", "age"};
String selection = "age > ?";
String[] selectionArgs = {"25"};
Cursor cursor = db.query("mytable", columns, selection, selectionArgs, null, null, null);

// 遍历结果集
if (cursor != null && cursor.moveToFirst()) {
    do {
        String name = cursor.getString(cursor.getColumnIndex("name"));
        int age = cursor.getInt(cursor.getColumnIndex("age"));
        // 处理获取到的数据
        Log.d("TAG", "Name: " + name + ", Age: " + age);
    } while (cursor.moveToNext());
}

// 关闭数据库连接
if (cursor != null) {
    cursor.close();
}
db.close();