Monday, 13 June 2011

query SQLite database with sorting

Work on last exercise, "Edit row in SQLite database using SQLiteDatabase.update()". Modify to have option to quary order by default, adn to quary order by KEY_CONTENT1.

query SQLite database with sorting

Modify main.xml to add two key, sortbyDefault and sortby1.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Enter content of column 1"
/>
<EditText
android:id="@+id/content1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Enter content of column 2"
/>
<EditText
android:id="@+id/content2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<Button
android:id="@+id/add"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Add"
/>
<Button
android:id="@+id/deleteall"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Delete All"
/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/sortbyDefault"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Sort By default"
/>
<Button
android:id="@+id/sortby1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Sort By Content 1"
/>
</LinearLayout>
<ListView
android:id="@+id/contentlist"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</LinearLayout>


Modify SQLiteAdapter.java to add method queueAll_SortBy_CONTENT1(), simple call sqLiteDatabase.query(MYDATABASE_TABLE, columns, null, null, null, null, KEY_CONTENT1) indirectly.
package com.exercise.AndroidSQLite;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase.CursorFactory;

public class SQLiteAdapter {

public static final String MYDATABASE_NAME = "MY_DATABASE";
public static final String MYDATABASE_TABLE = "MY_TABLE";
public static final int MYDATABASE_VERSION = 1;
public static final String KEY_ID = "_id";
public static final String KEY_CONTENT1 = "Content1";
public static final String KEY_CONTENT2 = "Content2";

//create table MY_DATABASE (ID integer primary key, Content text not null);
private static final String SCRIPT_CREATE_DATABASE =
"create table " + MYDATABASE_TABLE + " ("
+ KEY_ID + " integer primary key autoincrement, "
+ KEY_CONTENT1 + " text not null, "
+ KEY_CONTENT2 + " text not null);";

private SQLiteHelper sqLiteHelper;
private SQLiteDatabase sqLiteDatabase;

private Context context;

public SQLiteAdapter(Context c){
context = c;
}

public SQLiteAdapter openToRead() throws android.database.SQLException {
sqLiteHelper = new SQLiteHelper(context, MYDATABASE_NAME, null, MYDATABASE_VERSION);
sqLiteDatabase = sqLiteHelper.getReadableDatabase();
return this;
}

public SQLiteAdapter openToWrite() throws android.database.SQLException {
sqLiteHelper = new SQLiteHelper(context, MYDATABASE_NAME, null, MYDATABASE_VERSION);
sqLiteDatabase = sqLiteHelper.getWritableDatabase();
return this;
}

public void close(){
sqLiteHelper.close();
}

public long insert(String content1, String content2){

ContentValues contentValues = new ContentValues();
contentValues.put(KEY_CONTENT1, content1);
contentValues.put(KEY_CONTENT2, content2);
return sqLiteDatabase.insert(MYDATABASE_TABLE, null, contentValues);
}

public int deleteAll(){
return sqLiteDatabase.delete(MYDATABASE_TABLE, null, null);
}

public void delete_byID(int id){
sqLiteDatabase.delete(MYDATABASE_TABLE, KEY_ID+"="+id, null);
}

public void update_byID(int id, String v1, String v2){
ContentValues values = new ContentValues();
values.put(KEY_CONTENT1, v1);
values.put(KEY_CONTENT2, v2);
sqLiteDatabase.update(MYDATABASE_TABLE, values, KEY_ID+"="+id, null);
}

public Cursor queueAll(){
String[] columns = new String[]{KEY_ID, KEY_CONTENT1, KEY_CONTENT2};
Cursor cursor = sqLiteDatabase.query(MYDATABASE_TABLE, columns,
null, null, null, null, null);

return cursor;
}

public Cursor queueAll_SortBy_CONTENT1(){
String[] columns = new String[]{KEY_ID, KEY_CONTENT1, KEY_CONTENT2};
Cursor cursor = sqLiteDatabase.query(MYDATABASE_TABLE, columns,
null, null, null, null, KEY_CONTENT1);

return cursor;
}

public Cursor queueAll_SortBy_CONTENT2(){
String[] columns = new String[]{KEY_ID, KEY_CONTENT1, KEY_CONTENT2};
Cursor cursor = sqLiteDatabase.query(MYDATABASE_TABLE, columns,
null, null, null, null, KEY_CONTENT2);

return cursor;
}

public class SQLiteHelper extends SQLiteOpenHelper {

public SQLiteHelper(Context context, String name,
CursorFactory factory, int version) {
super(context, name, factory, version);
}

@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(SCRIPT_CREATE_DATABASE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub

}

}

}


Modify AndroidSQLite.java to add Button and Button.OnClickListener() of buttonSortDefault and buttonSort1.
package com.exercise.AndroidSQLite;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;

public class AndroidSQLite extends Activity {

EditText inputContent1, inputContent2;
Button buttonAdd, buttonDeleteAll;
Button buttonSortDefault, buttonSort1;

private SQLiteAdapter mySQLiteAdapter;
ListView listContent;

SimpleCursorAdapter cursorAdapter;
Cursor cursor;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

inputContent1 = (EditText)findViewById(R.id.content1);
inputContent2 = (EditText)findViewById(R.id.content2);
buttonAdd = (Button)findViewById(R.id.add);
buttonDeleteAll = (Button)findViewById(R.id.deleteall);

listContent = (ListView)findViewById(R.id.contentlist);

mySQLiteAdapter = new SQLiteAdapter(this);
mySQLiteAdapter.openToWrite();

cursor = mySQLiteAdapter.queueAll();
String[] from = new String[]{SQLiteAdapter.KEY_ID, SQLiteAdapter.KEY_CONTENT1, SQLiteAdapter.KEY_CONTENT2};
int[] to = new int[]{R.id.id, R.id.text1, R.id.text2};
cursorAdapter =
new SimpleCursorAdapter(this, R.layout.row, cursor, from, to);
listContent.setAdapter(cursorAdapter);
listContent.setOnItemClickListener(listContentOnItemClickListener);

buttonAdd.setOnClickListener(buttonAddOnClickListener);
buttonDeleteAll.setOnClickListener(buttonDeleteAllOnClickListener);

buttonSortDefault = (Button)findViewById(R.id.sortbyDefault);
buttonSort1 = (Button)findViewById(R.id.sortby1);

buttonSortDefault.setOnClickListener(new Button.OnClickListener(){

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
cursor = mySQLiteAdapter.queueAll();
String[] from = new String[]{SQLiteAdapter.KEY_ID, SQLiteAdapter.KEY_CONTENT1, SQLiteAdapter.KEY_CONTENT2};
int[] to = new int[]{R.id.id, R.id.text1, R.id.text2};
cursorAdapter =
new SimpleCursorAdapter(AndroidSQLite.this, R.layout.row, cursor, from, to);
listContent.setAdapter(cursorAdapter);
updateList();
}});

buttonSort1.setOnClickListener(new Button.OnClickListener(){

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
cursor = mySQLiteAdapter.queueAll_SortBy_CONTENT1();
String[] from = new String[]{SQLiteAdapter.KEY_ID, SQLiteAdapter.KEY_CONTENT1, SQLiteAdapter.KEY_CONTENT2};
int[] to = new int[]{R.id.id, R.id.text1, R.id.text2};
cursorAdapter =
new SimpleCursorAdapter(AndroidSQLite.this, R.layout.row, cursor, from, to);
listContent.setAdapter(cursorAdapter);
updateList();
}});


}

Button.OnClickListener buttonAddOnClickListener
= new Button.OnClickListener(){

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String data1 = inputContent1.getText().toString();
String data2 = inputContent2.getText().toString();
mySQLiteAdapter.insert(data1, data2);
updateList();
}

};

Button.OnClickListener buttonDeleteAllOnClickListener
= new Button.OnClickListener(){

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
mySQLiteAdapter.deleteAll();
updateList();
}

};

private ListView.OnItemClickListener listContentOnItemClickListener
= new ListView.OnItemClickListener(){

@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// TODO Auto-generated method stub

Cursor cursor = (Cursor) parent.getItemAtPosition(position);
final int item_id = cursor.getInt(cursor.getColumnIndex(SQLiteAdapter.KEY_ID));
String item_content1 = cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_CONTENT1));
String item_content2 = cursor.getString(cursor.getColumnIndex(SQLiteAdapter.KEY_CONTENT2));

AlertDialog.Builder myDialog
= new AlertDialog.Builder(AndroidSQLite.this);

myDialog.setTitle("Delete/Edit?");

TextView dialogTxt_id = new TextView(AndroidSQLite.this);
LayoutParams dialogTxt_idLayoutParams
= new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
dialogTxt_id.setLayoutParams(dialogTxt_idLayoutParams);
dialogTxt_id.setText("#" + String.valueOf(item_id));

final EditText dialogC1_id = new EditText(AndroidSQLite.this);
LayoutParams dialogC1_idLayoutParams
= new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
dialogC1_id.setLayoutParams(dialogC1_idLayoutParams);
dialogC1_id.setText(item_content1);

final EditText dialogC2_id = new EditText(AndroidSQLite.this);
LayoutParams dialogC2_idLayoutParams
= new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
dialogC2_id.setLayoutParams(dialogC2_idLayoutParams);
dialogC2_id.setText(item_content2);

LinearLayout layout = new LinearLayout(AndroidSQLite.this);
layout.setOrientation(LinearLayout.VERTICAL);
layout.addView(dialogTxt_id);
layout.addView(dialogC1_id);
layout.addView(dialogC2_id);
myDialog.setView(layout);

myDialog.setPositiveButton("Delete", new DialogInterface.OnClickListener() {
// do something when the button is clicked
public void onClick(DialogInterface arg0, int arg1) {
mySQLiteAdapter.delete_byID(item_id);
updateList();
}
});

myDialog.setNeutralButton("Update", new DialogInterface.OnClickListener() {
// do something when the button is clicked
public void onClick(DialogInterface arg0, int arg1) {
String value1 = dialogC1_id.getText().toString();
String value2 = dialogC2_id.getText().toString();
mySQLiteAdapter.update_byID(item_id, value1, value2);
updateList();
}
});

myDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
// do something when the button is clicked
public void onClick(DialogInterface arg0, int arg1) {

}
});

myDialog.show();


}};

@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
mySQLiteAdapter.close();
}



private void updateList(){
cursor.requery();
}

}


Download the files.

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