如何根据日期从数据库中检索数据

Question

我在 selection.xml 中创建了一个 EditText(date) 和 button(Update)。 日期使用 datepicker 来设置。

我有 2 个问题 我需要帮助。 当我单击editText时，会弹出日期选择器，在我选择日期后，单击更新，它将转到我的另一个布局（update.xml）。 如何确保我使用 datepicker 选择的日期与数据库中的日期相同。

2）在我的 update.xml 中，它将显示我在 selection.xml 中指定/搜索的特定日期的所有记录。

我是 android 新手，尤其是从数据库中检索和处理日期。 如前所述，我的问题需要帮助。 有人可以帮帮我吗？ 这是我的代码。

DBAdapter.java

public class DBAdapter {



    public static final String KEY_ROWID = "_id";
    public static final String KEY_DATE = "date";
    public static final String KEY_PRICE = "fuelprice";
    public static final String KEY_FUEL = "fuelpump";
    public static final String KEY_COST = "tcost";
    public static final String KEY_ODM = "odometer";
    public static final String KEY_CON = "fcon";

    private static final String TAG = "DBAdapter";

    private static final String DATABASE_NAME = "MyDB";
    private static final String DATABASE_TABLE = "fuelLog";
    private static final int DATABASE_VERSION = 2;



    private static final String DATABASE_CREATE =
            "create table fuelLog (_id integer primary key autoincrement, " + "date text not null, fuelprice text not null, fuelpump text not null, tcost text not null, odometer text not null, fcon text not null);";


        private final Context context;    

        private DatabaseHelper DBHelper;
        private SQLiteDatabase db;

        public DBAdapter(Context ctx){
            this.context = ctx;
            DBHelper = new DatabaseHelper(context);
        }

        private static class DatabaseHelper extends SQLiteOpenHelper 
        {
            DatabaseHelper(Context context){
                super(context, DATABASE_NAME, null, DATABASE_VERSION);
            }

            public void onCreate(SQLiteDatabase db) 
            {
                try{
                    db.execSQL(DATABASE_CREATE);    
                }catch (SQLException e){
                    e.printStackTrace();
                }
            }//onCreate

            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 contacts");
                onCreate(db);
            }//onUpgrade

        }//DatabaseHelper


        public DBAdapter open() throws SQLException 
        {
            db = DBHelper.getWritableDatabase();
            return this;
        }//open


        //---closes the database---    
        public void close() 
        {
            DBHelper.close();
        }//close


        //---insert a log into the database---
        public long insertLog(String date, String fuelprice, String fuelpump,String tcost,String odometer,String fcon ) 
        {
            ContentValues initialValues = new ContentValues();
            initialValues.put(KEY_DATE, date);
            initialValues.put(KEY_PRICE, fuelprice);
            initialValues.put(KEY_FUEL, fuelpump);
            initialValues.put(KEY_COST, tcost);
            initialValues.put(KEY_ODM, odometer);
            initialValues.put(KEY_CON, fcon);


            return db.insert(DATABASE_TABLE, null, initialValues);
        }//insertLog
}

selection.java

public class selection extends Activity {


    Button newButton;
    Button updateButton;
    Button deleteButton;
    Button summaryButton;
    static EditText updateEdit;
    private int mYear;
    private int mMonth;
    private int mDay;

    static final int DATE_DIALOG_ID = 0;




    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.selection);

        updateEdit = (EditText)findViewById(R.id.updateEdit);


        updateEdit.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                   // showDialog(DATE_DIALOG_ID);
                    DialogFragment newFragment = new DatePickerFragment();
                    newFragment.show(getFragmentManager(), "datePicker");
                }
            });             

        newButton = (Button) findViewById(R.id.newBTN);
         newButton.setOnClickListener(new OnClickListener()
        {
            public void onClick(View v)
            {

                 Intent mainAct=new Intent(getApplicationContext(),MainActivity.class);
                 startActivity(mainAct);

            }                   
            });

         updateButton = (Button) findViewById(R.id.updateBTN);
         updateButton.setOnClickListener(new OnClickListener()
        {
            public void onClick(View v)
            {

                 Intent updateAct=new Intent(getApplicationContext(),update.class);
                 startActivity(updateAct);

            }

            });

         deleteButton = (Button) findViewById(R.id.deleteBTN);
         deleteButton.setOnClickListener(new OnClickListener()
        {
            public void onClick(View v)
            {                   
                Intent updateAct=new Intent(getApplicationContext(),update.class);
                 startActivity(updateAct);

            }

            });

         summaryButton = (Button) findViewById(R.id.summaryBTN);
         summaryButton.setOnClickListener(new OnClickListener()
        {
            public void onClick(View v)
            {

                Intent summaryView=new Intent(getApplicationContext(),summary.class);
                 startActivity(summaryView);

            }                   
            });

        }
    public static class DatePickerFragment extends DialogFragment
    implements DatePickerDialog.OnDateSetListener {

        public EditText editText;
        DatePicker dpResult;

    public Dialog onCreateDialog(Bundle savedInstanceState) {
    // Use the current date as the default date in the picker

    final Calendar c = Calendar.getInstance();
    int year = c.get(Calendar.YEAR);
    int month = c.get(Calendar.MONTH);
    int day = c.get(Calendar.DAY_OF_MONTH);
    //return new DatePickerDialog(getActivity(), (EditSessionActivity)getActivity(), year, month, day);

    // Create a new instance of DatePickerDialog and return it
    return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    public void onDateSet(DatePicker view, int year, int month, int day) {

        updateEdit.setText(String.valueOf(day) + "/"
                + String.valueOf(month + 1) + "/" + String.valueOf(year));
        // set selected date into datepicker also


    }
    }
}

update.java（我还没有进行编码，因为我不知道如何根据日期从数据库中检索数据）

public class update extends Activity{
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.update);
}
}

selection.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
     android:orientation="vertical"
    android:layout_height="fill_parent"
    tools:context=".MainActivity" >


   <TableLayout 
        android:id="@+id/tableLayout1" 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        android:stretchColumns="1 ">

        <TableRow 
            android:id="@+id/tableRow1" 
            android:layout_width="wrap_content" 
            android:layout_height="wrap_content">

             <Button
            android:id="@+id/newBTN"
            android:text="New"
            android:layout_width="wrap_content"
            android:layout_height="60px" >
        </Button>
       </TableRow>

         <TableRow 
            android:id="@+id/tableRow2" 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <Button
            android:id="@+id/updateBTN"
            android:text="Update"
            android:layout_width="wrap_content"
            android:layout_height="60px" >
        </Button>
            <EditText
                android:id="@+id/updateEdit" 
                android:text="" 
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content"
                  android:editable="false"
                android:enabled="true">
            </EditText>
        </TableRow>
         <TableRow 
            android:id="@+id/tableRow3" 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <Button
            android:id="@+id/deleteBTN"
            android:text="Delete"
            android:layout_width="wrap_content"
            android:layout_height="60px" >
        </Button>
            <EditText
                android:id="@+id/deleteEdit" 
                android:text="" 
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </EditText>
        </TableRow>


          <TableRow 
            android:id="@+id/tableRow4" 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <Button
            android:id="@+id/summaryBTN"
            android:text="Summary"
            android:layout_width="wrap_content"
            android:layout_height="60px" >
        </Button>    
        </TableRow>           

        </TableLayout>        
</LinearLayout>

更新.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
     android:orientation="vertical"
    android:layout_height="fill_parent"
    tools:context=".MainActivity" >


   <TableLayout 
        android:id="@+id/tableLayout1" 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        android:stretchColumns="1">

        <TableRow 
            android:id="@+id/tableRow1" 
            android:layout_width="wrap_content" 
            android:layout_height="wrap_content">
             <TextView 
                android:id="@+id/datetxtview"
                android:text="@string/date"  
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </TextView>
              <EditText
                android:id="@+id/date" 
                android:text=""
                android:inputType="date" 
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content"
                   android:editable="false">
            </EditText>
       </TableRow>

         <TableRow 
            android:id="@+id/tableRow2" 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <TextView 
                android:id="@+id/fuelpricetxtview" 
                android:text="@string/fuelprice"
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </TextView>
            <EditText
                android:id="@+id/fuelprice" 
                android:text="" 
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </EditText>
        </TableRow>
         <TableRow 
            android:id="@+id/tableRow3" 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <TextView 
                android:id="@+id/fuelpumptxtview" 
                android:text="@string/fuelpump"
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </TextView>
            <EditText
                android:id="@+id/fuelpump" 
                android:text="" 
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </EditText>
        </TableRow>


          <TableRow 
            android:id="@+id/tableRow4" 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <TextView 
                android:id="@+id/totalcosttxtview" 
                android:text="@string/totalcost"
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </TextView>

            <TextView
                android:id="@+id/tcost"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="" />

        </TableRow>



         <TableRow 
            android:id="@+id/tableRow5" 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <TextView 
                android:id="@+id/odometertxtview" 
                android:text="@string/odometer"
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </TextView>

            <EditText
                android:id="@+id/odometer"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:ems="10" >

                <requestFocus />
            </EditText>

        </TableRow>   
         <TableRow 
            android:id="@+id/tableRow6" 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <TextView 
                android:id="@+id/fctxtview" 
                android:text="@string/fc"
                android:layout_width="wrap_content" 
                android:layout_height="wrap_content">
            </TextView>

            <TextView
                android:id="@+id/fcon"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="" />

        </TableRow>     
        </TableLayout>


    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" >

          <Button
            android:id="@+id/updateBTN"
            android:text="Update"
            android:layout_width="wrap_content"
            android:layout_height="60px" >
        </Button>
        <Button
            android:id="@+id/cancelBTN"
            android:text="@string/cancel"
            android:layout_width="wrap_content"
            android:layout_height="60px" >
        </Button>
    </LinearLayout>
</LinearLayout>

Answer 1

使用它从日期选择器中检索日期：

public class MainActivity extends Activity {

    static EditText mDateDisplay;
    private Button mPickDate;
    private int mYear;
    private int mMonth;
    private int mDay;

    static final int DATE_DIALOG_ID = 0;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        mDateDisplay = (EditText) findViewById(R.id.editText1);
        mPickDate = (Button) findViewById(R.id.button1);


        mPickDate.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
               // showDialog(DATE_DIALOG_ID);
                DialogFragment newFragment = new DatePickerFragment();
                newFragment.show(getFragmentManager(), "datePicker");
            }
        });


    }


    public static class DatePickerFragment extends DialogFragment
    implements DatePickerDialog.OnDateSetListener {

        public EditText editText;
        DatePicker dpResult;

    public Dialog onCreateDialog(Bundle savedInstanceState) {
    // Use the current date as the default date in the picker

    final Calendar c = Calendar.getInstance();
    int year = c.get(Calendar.YEAR);
    int month = c.get(Calendar.MONTH);
    int day = c.get(Calendar.DAY_OF_MONTH);
    //return new DatePickerDialog(getActivity(), (EditSessionActivity)getActivity(), year, month, day);

    // Create a new instance of DatePickerDialog and return it
    return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    public void onDateSet(DatePicker view, int year, int month, int day) {

        mDateDisplay .setText(String.valueOf(day) + "/"
                + String.valueOf(month + 1) + "/" + String.valueOf(year));
        // set selected date into datepicker also


    }
    }
}

对于日期检索和插入，请参见以下步骤：

您不能通过 Java 包装器“ContentValues”使用日期时间函数。您可以通过这种方式实现：

1) 可以使用SQLiteDatabase.execSQL（原始SQL查询）

 dbObj.execSQL("INSERT INTO "+DATABASE_TABLE+" VALUES (null, datetime()) ");

2) 你可以使用 SimpleDateFormat

// setting the format to sql date time
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
Date date = new Date();
ContentValues initialValues = new ContentValues(); 
initialValues.put("date_time", dateFormat.format(date));
long recordId = mDb.insert(DB_TABLE_NAME, null, initialValues);

3）您将日期值以（长类型）毫秒存储在数据库中，并且为了显示您可以对其进行格式化，

 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.Calendar;

System.out.println(getDate(82233213123L, "dd/MM/yyyy hh:mm:ss.SSS"));

// Return date in specified format.
// milliSeconds Date in milliseconds
// dateFormat Date format 
// return date as string in specified format

public static String formatDate(long milliSeconds, String dateFormat)
{

    DateFormat formatter = new SimpleDateFormat(dateFormat);

// Create a calendar object that will convert the date and time value in milliseconds to date. 
   Calendar calendar = Calendar.getInstance();
 calendar.setTimeInMillis(milliSeconds);
 return formatter.format(calendar.getTime());
   }
 }

1 秒 = 1000 毫秒，所以如果要添加 1 小时，请使用此公式

  currentTImeMilli + (60 * 60 * 1000)

Answer 2

您可以将日期转换为String，然后将字符串保存到数据库中：

String dateText = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()

日期将如下所示 2014-01-19 04:51:48

在您的日期选择器中：

SimpleDateFormat dateformat = new SimpleDateFormat("yyyy-MM-dd");
String dateFormat = dateformat.format(new Date(datePicker.getYear(),     
datePicker.getMonth(), datePicker.getDayOfMonth()));