java - 使用 setFilterQueryProvider 从数据库过滤数据？

Question

我这里有我的代码。数据库中的数据按标题过滤，如何按标题或作者过滤数据？我认为它位于 Catalogue.java 上的这些代码行上:

dataAdapter.setFilterQueryProvider(new FilterQueryProvider() {
         public Cursor runQuery(CharSequence constraint) {
             return dbHelper.fetchCollectionsByTitle(constraint.toString());

这是我的代码:

目录.java

package com.cvsu.catalogue.db;

import com.cvsu.catalogue.R;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.FilterQueryProvider;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
//import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

@SuppressLint("NewApi")
public class Catalogue extends Activity {

 private CollectionsDbAdapter dbHelper;
 private SimpleCursorAdapter dataAdapter;

 public final static String TITLE_EXTRA = "com.cvsu.catalogue.db._TITLE";
 public final static String AUTHOR_EXTRA = "com.cvsu.catalogue.db._AUTHOR";
 public final static String LOCATION_EXTRA = "com.cvsu.catalogue.db._LOCATION";
 public final static String CALLNUMBER_EXTRA = "com.cvsu.catalogue.db._CALLNUMBER";
 public final static String PUBLISHER_EXTRA = "com.cvsu.catalogue.db._PUBLISHER";
 public final static String DATEPUBLISHED_EXTRA = "com.cvsu.catalogue.db._DATEPUBLISHED";
 public final static String DESCRIPTION_EXTRA = "com.cvsu.catalogue.db._DESCRIPTION";


 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.catalogue_title);

  dbHelper = new CollectionsDbAdapter(this);
  dbHelper.open();

  //Generate ListView from SQLite Database
  displayListView();

 }

 private void displayListView() {


  Cursor cursor = dbHelper.fetchAllCollections();

  // The desired columns to be bound
  String[] columns  = new String[] {
    CollectionsDbAdapter.KEY_TITLE,
    CollectionsDbAdapter.KEY_AUTHOR,
    CollectionsDbAdapter.KEY_LOCATION,
    CollectionsDbAdapter.KEY_CALLNUMBER,
    CollectionsDbAdapter.KEY_PUBLISHER,
    CollectionsDbAdapter.KEY_DATEPUBLISHED,
    CollectionsDbAdapter.KEY_DESCRIPTION
  };

  // the XML defined views which the data will be bound to
  int[] to = new int[] {
    R.id.txtTitle,
    R.id.txtAuthor,
    //R.id.location,
    //R.id.callnumber,
    //R.id.publisher,
    //R.id.datepublished,
    //R.id.description,
  };

  // create the adapter using the cursor pointing to the desired data
  //as well as the layout information
  dataAdapter = new SimpleCursorAdapter(
    this, R.layout.book_info_title,
    cursor,
    columns,
    to,
    0);

  final ListView listView = (ListView) findViewById(R.id.listView1);
  // Assign adapter to ListView
  listView.setAdapter(dataAdapter);


  listView.setOnItemClickListener(new OnItemClickListener() {
   @Override
   public void onItemClick(AdapterView<?> listview, View view,
     int position, long id ) {
   // Get the cursor, positioned to the corresponding row in the result set
   /*Cursor cursor = (Cursor) listView.getItemAtPosition(position);

   // Get the state's capital from this row in the database.
   String bookTitle =
    cursor.getString(cursor.getColumnIndexOrThrow("title"));
   Toast.makeText(getApplicationContext(),
   bookTitle, Toast.LENGTH_SHORT).show();*/

   Intent i = new Intent (CatalogueTitle.this, BookInfoPage.class);

   i.putExtra(TITLE_EXTRA, String.valueOf(id));
   i.putExtra(AUTHOR_EXTRA, String.valueOf(id));
   i.putExtra(LOCATION_EXTRA, String.valueOf(id));
   i.putExtra(CALLNUMBER_EXTRA, String.valueOf(id));
   i.putExtra(PUBLISHER_EXTRA, String.valueOf(id));
   i.putExtra(DATEPUBLISHED_EXTRA, String.valueOf(id));
   i.putExtra(DESCRIPTION_EXTRA, String.valueOf(id));
   startActivity(i);
   }
  });

  EditText myFilter = (EditText) findViewById(R.id.myFilter);
  myFilter.addTextChangedListener(new TextWatcher() {

   public void afterTextChanged(Editable s) {
   }

   public void beforeTextChanged(CharSequence s, int start,
     int count, int after) {
   }

   public void onTextChanged(CharSequence s, int start,
     int before, int count) {
    dataAdapter.getFilter().filter(s.toString());
   }
  });

  dataAdapter.setFilterQueryProvider(new FilterQueryProvider() {
         public Cursor runQuery(CharSequence constraint) {
             return dbHelper.fetchCollectionsByTitle(constraint.toString());
         }
     });

 }

public static void main(String[] args) {

}
}

集合.Java

package com.cvsu.catalogue.db;

public class Collections {

   String title = null;
   String author = null;
   String location = null;
   String callnumber = null;
   String publisher = null;
   String datepublished = null;
   String description = null;

   public String getTitle() {
    return title;
   }
   public void setTitle(String title) {
    this.title = title;
   }
   public String getAuthor() {
    return author;
   }
   public void setAuthor(String author) {
    this.author = author;
   }
   public String getLocation() {
    return location;
   }
   public void setLocation(String location) {
    this.location = location;
   }
   public String getCallNumber() {
    return callnumber;
   }
   public void setCallNumber(String callnumber) {
    this.callnumber = callnumber;
   }
   public String getPublisher() {
        return publisher;
  }
  public void setPublisher(String publisher) {
   this.publisher = publisher;
  }
   public String getDatePublished() {
        return datepublished;
  }
  public void setDatePublished(String datepublished) {
    this.datepublished = datepublished;
  }
  public String getDescription() {
    return description;
  }
  public void setDescription(String description) {
    this.description = description;
  } 
  }

CollectionsDbAdapter.java

package com.cvsu.catalogue.db;

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

public class CollectionsDbAdapter {

 public static final String KEY_ROWID = "_id";
 public static final String KEY_TITLE = "title";
 public static final String KEY_AUTHOR = "author";
 public static final String KEY_LOCATION = "location";
 public static final String KEY_CALLNUMBER = "callnumber";
 public static final String KEY_PUBLISHER = "publisher";
 public static final String KEY_DATEPUBLISHED = "datepublished";
 public static final String KEY_DESCRIPTION = "description";

 private static final String TAG = "CollectionsDbAdapter";
 private DatabaseHelper mDbHelper;
 private SQLiteDatabase mDb;

 private static final String DATABASE_NAME = "LibraryCollections";
 private static final String SQLITE_TABLE = "Collections";
 private static final int DATABASE_VERSION = 1;

 private final Context mCtx;

 private static final String DATABASE_CREATE =
  "CREATE TABLE if not exists " + SQLITE_TABLE + " (" +
  KEY_ROWID + " integer PRIMARY KEY autoincrement," +
  KEY_TITLE + "," +
  KEY_AUTHOR + "," +
  KEY_LOCATION + "," +
  KEY_CALLNUMBER + "," +
  KEY_PUBLISHER + "," +
  KEY_DATEPUBLISHED + "," +
  KEY_DESCRIPTION + "," +
  " UNIQUE (" + KEY_CALLNUMBER +"));";

 private static class DatabaseHelper extends SQLiteOpenHelper {

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


  @Override
  public void onCreate(SQLiteDatabase db) {
   Log.w(TAG, DATABASE_CREATE);
   db.execSQL(DATABASE_CREATE);
  }

  @Override
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
   Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
     + newVersion + ", which will destroy all old data");
   db.execSQL("DROP TABLE IF EXISTS " + SQLITE_TABLE);
   onCreate(db);
  }
 }

 public CollectionsDbAdapter(Context ctx) {
  this.mCtx = ctx;
 }

 public CollectionsDbAdapter open() throws SQLException {
  mDbHelper = new DatabaseHelper(mCtx);
  mDb = mDbHelper.getWritableDatabase();
  return this;
 }

 public void close() {
  if (mDbHelper != null) {
   mDbHelper.close();
  }
 }

 public long createCollections(String title, String author,
   String location, String callnumber, String publisher, String datepublished, String description) {

  ContentValues initialValues = new ContentValues();
  initialValues.put(KEY_TITLE, title);
  initialValues.put(KEY_AUTHOR, author);
  initialValues.put(KEY_LOCATION, location);
  initialValues.put(KEY_CALLNUMBER, callnumber);
  initialValues.put(KEY_PUBLISHER, publisher);
  initialValues.put(KEY_DATEPUBLISHED, datepublished);
  initialValues.put(KEY_DESCRIPTION, description);

  return mDb.insert(SQLITE_TABLE, null, initialValues);
 }

 public Cursor fetchCollectionsByTitle(String inputText) throws SQLException {
  Log.w(TAG, inputText);
  Cursor mCursor = null;
  if (inputText == null  ||  inputText.length () == 0)  {
   mCursor = mDb.query(SQLITE_TABLE, new String[] {KEY_ROWID,
     KEY_TITLE, KEY_AUTHOR, KEY_LOCATION, KEY_CALLNUMBER, KEY_PUBLISHER, KEY_DATEPUBLISHED, KEY_DESCRIPTION},
     null, null, null, null, null);

  }

  else {
   mCursor = mDb.query(true, SQLITE_TABLE, new String[] {KEY_ROWID,
     KEY_TITLE, KEY_AUTHOR, KEY_LOCATION, KEY_CALLNUMBER, KEY_PUBLISHER, KEY_DATEPUBLISHED, KEY_DESCRIPTION},
     KEY_TITLE + " like '%" + inputText + "%'", null,
     null, null, null, null);
  }

  if (mCursor != null) {
       mCursor.moveToFirst();
      }

      return mCursor;

     }

 public Cursor fetchCollectionsByAuthor(String inputText) throws SQLException {
      Log.w(TAG, inputText);
      Cursor mCursor = null;
      if (inputText == null  ||  inputText.length () == 0)  {
       mCursor = mDb.query(SQLITE_TABLE, new String[] {KEY_ROWID,
         KEY_TITLE, KEY_AUTHOR, KEY_LOCATION, KEY_CALLNUMBER, KEY_PUBLISHER, KEY_DATEPUBLISHED, KEY_DESCRIPTION},
         null, null, null, null, null);

      }

      else {
       mCursor = mDb.query(true, SQLITE_TABLE, new String[] {KEY_ROWID,
         KEY_TITLE, KEY_AUTHOR, KEY_LOCATION, KEY_CALLNUMBER, KEY_PUBLISHER, KEY_DATEPUBLISHED, KEY_DESCRIPTION},
         KEY_AUTHOR + " like '%" + inputText + "%'", null,
         null, null, null, null);
      }

      if (mCursor != null) {
           mCursor.moveToFirst();
          }

          return mCursor;

         }

 public Cursor fetchAllCollections() {

  Cursor mCursor = mDb.query(SQLITE_TABLE, new String[] {KEY_ROWID,
    KEY_TITLE, KEY_AUTHOR, KEY_LOCATION, KEY_CALLNUMBER, KEY_PUBLISHER, KEY_DATEPUBLISHED, KEY_DESCRIPTION},
    null, null, null, null, null);

  if (mCursor != null) {
   mCursor.moveToFirst();
  }
  return mCursor;
 }
}

Answer 1

@Override
        public Cursor runQuery(CharSequence constraint) {
            Cursor cur = null;
             database.openDataBase();
             if(constraint!=null){
                 cur = database.selectDataWithConstrain(constraint.toString());
             }

        return cur;
        }

使用此约束在数据库类中编写查询并获取标题或作者所需的数据

 public Cursor selectDataWithConstrain(String c) {

      // TODO Auto-generated method stub
         Cursor cursor = myDataBase.rawQuery("SELECT * FROM  tbl_xxx WHERE title LIKE '%"+c+"%'", null);

         return cursor;
  }