在输入表中，值每周都在变化。因此，下周的E列将是A而不是F，此时我会想要E字段。
因此，必须选择具有A的字段，但具有A的字段应该是表中具有A作为记录的最后一个字段。
输入表：
public class MainActivity extends AppCompatActivity {
private SectionsPagerAdapter mSectionsPagerAdapter;
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//Fragment
new Reproducir.LlenarDatosReproduccion();
Toast.makeText(getApplicationContext(),"Entró al play",Toast.LENGTH_SHORT).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public static class PlaceholderFragment extends Fragment {
private static final String ARG_SECTION_NUMBER = "section_number";
public PlaceholderFragment() {
}
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
if(position==0){
return new Reproducir();
}else {
return PlaceholderFragment.newInstance(position + 1);
}
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "REPRODUCIR";
case 1:
return "PLAYLIST";
case 2:
return "CANCIONES";
}
return null;
}
}
输出：
public class Reproducir extends Fragment {
private static TextView tvTitle,tvArtist;
FloatingActionButton fabPlay;
private String url="http://streaming.hotmixradio.fr/hotmixradio-hits-128.mp3";
private ImageView ivAlbum;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View rootView=inflater.inflate(R.layout.tab_reproduccion,container,false);
//new LlenarDatosReptoduccion();
tvTitle=(TextView)rootView.findViewById(R.id.tv_title);
//tvTitle.setText(url);
tvArtist=(TextView)rootView.findViewById(R.id.tv_title);
return rootView;
}
public static class LlenarDatosReproduccion extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
try {
return downloadUrl(urls[0]);
} catch (IOException e) {
return "Ups! Error.Parece que la url es inválida";
}
}
@Override
protected void onPostExecute(String result) {
Log.i("POSTExecute","Ingesó antes del try");
try {
Log.i("POSTExecute","Ingesó al try");
JSONObject responseJSON = new JSONObject(result.toString());
JSONObject cancionJSON = responseJSON.getJSONObject("cancion");
tvTitle.setText(cancionJSON.get("title").toString());
Log.d("ARTISTA",cancionJSON.get("artist").toString());
//tvArtist.setText(cancionJSON.getString(2));
} catch (JSONException e) {
Log.i("POSTExecute","Ingesó al catch!");
e.printStackTrace();
}
super.onPostExecute(result);
}
}
private static String downloadUrl(String myUrl) throws IOException {
Log.i("URL"," LA URL URL URL: "+myUrl);
myUrl.replace(" ","%20");
InputStream is=null;
int lengh=500;
try{
return "{\"cancion\":{\"title\":\"Versace On The Floor (Vs David Guetta)\",\"artist\":\"BRUNO MARS\",\"duration\":\"18783\"}}";
}finally {
if(is!=null){
is.close();
}
}
}
答案 0 :(得分：0)
我知道如果您需要一个逻辑来获取可以使用此代码的结果，那么您的数据会因某种原因而非标准化：
DECLARE @table TABLE (A varchar(3), B varchar(3),C varchar(3), D varchar(3), E varchar(3))
;WITH cte
AS (SELECT ColumnName
,ColumnValue
,Row_number()
OVER(
partition BY ColumnName
ORDER BY Rn) ResultOrder
FROM (SELECT Row_number() OVER (ORDER BY (SELECT NULL))Rn,a ,b ,c ,d ,e FROM @table) p
UNPIVOT ( ColumnValue
FOR ColumnName IN( a ,b ,c ,d ,e)) AS unpvt),
cte1
AS (SELECT Ntile(5)
OVER(
ORDER BY ColumnName) ColumnId
,*
FROM cte),
cte2
AS (SELECT DISTINCT Isnull(NULLIF(ColumnId - 1, 0), 5) ColumnId
,ColumnName
FROM cte1
WHERE ColumnValue = 'F')
SELECT result
FROM (SELECT CASE ColumnId
WHEN 1 THEN 'A'
WHEN 2 THEN 'B'
WHEN 3 THEN 'C'
WHEN 4 THEN 'D'
WHEN 5 THEN 'E'
END Result
,0 ResultOrder
FROM cte2
UNION
SELECT ColumnValue
,resultorder
FROM cte1 a
WHERE EXISTS (SELECT 1
FROM cte2 b
WHERE a.ColumnId = b.ColumnId)) AS R
ORDER BY resultorder
结果
insert @table VALUES
('A','A','A','A','F')
,('12','32','43','23','2')
A B C D E
---- ---- ---- ---- ----
A A A A F
12 32 43 23 2
result
------
D
23
A
结果
insert @table VALUES
('F','A','A','A','A')
,('12','32','43','23','2')
A B C D E
---- ---- ---- ---- ----
F A A A A
12 32 43 23 2
result
------
E
A
2
说明：
你可以使用
SELECT ColumnValue Result
FROM cte1 a
WHERE EXISTS (SELECT 1
FROM cte2 b
WHERE a.ColumnId = b.ColumnId)
Result
------
A
23
(2 row(s) affected)
OR
SELECT ColumnValue Result
FROM cte1 a
WHERE EXISTS (SELECT 1
FROM cte2 b
WHERE a.ColumnId = b.ColumnId)
AND a.ResultOrder = 2
Result
------
23
(1 row(s) affected)