从 SQLite 数据库中检索数据并将其显示到 ListView -android
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Retrieving data from SQLite database and display it into ListView -android
提问by danish
I created a database(mydb) with a table(student) in the onCreate function and then entered values dynamically using a button click.Now I want to retrieve all the data from the table student on a button click and display it into listview.
我在 onCreate 函数中创建了一个带有表（student）的数据库（mydb），然后使用按钮单击动态输入值。现在我想通过单击按钮从表 student 中检索所有数据并将其显示到listview 中。
public class MainActivity extends Activity
{
String name, phone;
SQLiteDatabase db;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
db=openOrCreateDatabase("mydb", MODE_PRIVATE, null);
db.execSQL("CREATE TABLE IF NOT EXISTS student(dbname VARCHAR, dbphone VARCHAR);");
}
public void btnaddtodb(View v)
{
EditText edtxtname = (EditText)findViewById(R.id.edtxtname);
EditText edtxtphone = (EditText)findViewById(R.id.edtxtphone);
name=edtxtname.getText().toString();
phone=edtxtphone.getText().toString();
db.execSQL("INSERT INTO student values('"+name+"','"+phone+"');");
edtxtname.setText("");
edtxtphone.setText("");
}
}
回答by Lal
Try doing this...It shows all the values in table in a LinearLayout as a list
尝试这样做...它将 LinearLayout 中表格中的所有值显示为列表
try{
mydb = openOrCreateDatabase(DBNAME, Context.MODE_PRIVATE,null);
Cursor allrows = mydb.rawQuery("SELECT * FROM "+ TABLE, null);
System.out.println("COUNT : " + allrows.getCount());
Integer cindex = allrows.getColumnIndex("BOOK_DATE");
Integer cindex1 = allrows.getColumnIndex("TRIP_DATE");
Integer cindex2 = allrows.getColumnIndex("LOCATION");
TextView t = new TextView(MybookingsActivity.this);
t.setText("========================================");
//Linear.removeAllViews();
Linear.addView(t);
if(allrows.moveToFirst()){
do{
LinearLayout id_row = new LinearLayout(MybookingsActivity.this);
LinearLayout book_date_row = new LinearLayout(MybookingsActivity.this);
LinearLayout trip_date_row= new LinearLayout(MybookingsActivity.this);
LinearLayout location_row= new LinearLayout(MybookingsActivity.this);
LinearLayout feedback_row= new LinearLayout(MybookingsActivity.this);
final TextView id_ = new TextView(MybookingsActivity.this);
final TextView book_date = new TextView(MybookingsActivity.this);
final TextView trip_date = new TextView(MybookingsActivity.this);
final TextView location = new TextView(MybookingsActivity.this);
final TextView sep = new TextView(MybookingsActivity.this);
final Button feedback = new Button(MybookingsActivity.this);
final String ID = allrows.getString(0);
String BOOK_DATE= allrows.getString(1);
String TRIP_DATE= allrows.getString(2);
String LOCATION= allrows.getString(3);
id_.setTextColor(Color.RED);
id_.setPadding(20, 5, 0, 5);
book_date.setTextColor(Color.RED);
book_date.setPadding(20, 5, 0, 5);
trip_date.setTextColor(Color.RED);
trip_date.setPadding(20, 5, 0, 5);
location.setTextColor(Color.RED);
location.setPadding(20, 5, 0, 5);
System.out.println("BOOK_DATE " + allrows.getString(cindex) + " TRIP_DATE : "+ allrows.getString(cindex1)+ " LOCATION : "+ allrows.getString(cindex2));
System.out.println("ID : "+ ID + " || BOOK_DATE " + BOOK_DATE + "|| TRIP_DATE : "+ TRIP_DATE+ "|| LOCATION : "+LOCATION);
id_.setText("ID : " + ID);
id_row.addView(id_);
Linear.addView(id_row);
book_date.setText("BOOK_DATE : "+BOOK_DATE);
book_date_row.addView(book_date);
Linear.addView(book_date_row);
trip_date.setText("TRIP_DATE : " + TRIP_DATE);
trip_date_row.addView(trip_date);
Linear.addView(trip_date_row);
location.setText("LOCATION : " + LOCATION);
location_row.addView(location);
Linear.addView(location_row);
feedback.setText("Feedback");
feedback.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent=new Intent(MybookingsActivity.this,FeedbackActivity.class);
intent.putExtra("id", ID);
startActivity(intent);
}
});
feedback_row.addView(feedback);
Linear.addView(feedback_row);
sep.setText("---------------------------------------------------------------");
Linear.addView(sep);
}
while(allrows.moveToNext());
}
mydb.close();
}catch(Exception e){
Toast.makeText(getApplicationContext(), "Error encountered."+e.toString(), Toast.LENGTH_LONG).show();
}
Try it..Dont forget to change the dbname,tablename and fielnames..
试试吧..不要忘记更改 dbname、tablename 和 fielnames..
回答by J Jiang
Usually, you can always use the ArrayAdapterto show something in listview. (there is a good tutorialabout it and many other ones you can find on Internet)
通常，您始终可以使用ArrayAdapter来在列表视图中显示某些内容。（有一个关于它的很好的教程，您可以在互联网上找到许多其他教程）
For something in db, besides the basic ArrayAdapter, you can also use CursorAdapterwhich has some extra benefits such as dynamic loading and auto refresh.
对于 db 中的某些内容，除了 basic 之外ArrayAdapter，您还可以使用CursorAdapterwhich 具有一些额外的好处，例如动态加载和自动刷新。
To use CursorAdapter, Let your Activityimplements LoaderCallback<Cursor>and its required callbacks.
要使用CursorAdapter，让您的Activity实现LoaderCallback<Cursor>及其所需的回调。
Init a CursorAdapterand set it to the ListView.
初始化 aCursorAdapter并将其设置为ListView.
In the CreateLoader(...)method, query whatever you need.
在CreateLoader(...)方法中，查询您需要的任何内容。
Remember to implement the newViewand bindViewproperly.
请记住正确实施newView和bindView。
A simplest sample may looks like below:
一个最简单的示例可能如下所示：
public class TestActivity extends Activity implements LoaderCallbacks<Cursor>{
ListView listview;
CursorAdapter cursorAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
cursorAdapter = new CursorAdapter(this, null) {
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
LayoutInflater inflater =
(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView;
rowView = inflater.inflate(R.layout.device_list_item, parent, false);
bindView(rowView, context, cursor);
return rowView;
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
TextView textView = view.findViewById(R.id.text);
textView.setText(cursor.getString(0));
}
};
}
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
return db.query(...);
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
cursorAdapter.swapCursor(data);
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
cursorAdapter.swapCursor(null);
}
}
回答by J Jiang
USE this tutorial my be it help you.1> Android-sqlite-and-listview-example
使用本教程我会帮助你。1> Android-sqlite-and-listview-example
