Android将DATE（now）添加到SQLite数据库

Question

目前我的SQLite数据库工作得很好，我已经阅读了各种方法，如this one来实现这一目标，尽管目前我在设置Date构造函数时遇到问题，以及如何定义使用的数据在把它的数据库（和得到它回来了！）

到目前为止，我已经使用静态最后弦乐来定义我的数据变量，notsure这是使用日期的正确方法。

我不关心的时候，只是入门的创建日期。

下面是我的java类：

import java.sql.Date; 
import java.text.SimpleDateFormat; 

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; 

public class Stats { 

    public static final String KEY_ROWID = "_id"; 
    public static final String KEY_WEIGHT = "weight"; 
    public static final String KEY_WAIST = "waist"; 
    public static final String KEY_CHEST = "chest"; 
    public static final String KEY_LEGS = "legs"; 
    public static final String KEY_ARMS = "arms"; 
    public static final String KEY_DATE = "date"; 


    private static final String DATABASE_NAME = "statsDB"; 
    private static final String DATABASE_TABLE = "personalStats"; 
    private static final int DATABASE_VERSION = 3; 

    private DbHelper ffHelper; 
    private final Context ffContext; 
    private SQLiteDatabase ffDatabase; 

    private static class DbHelper extends SQLiteOpenHelper { 

     public DbHelper(Context context) { 
      super(context, DATABASE_NAME, null, DATABASE_VERSION); 

     } 

     @Override 
     public void onCreate(SQLiteDatabase db) { 
      db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" + KEY_ROWID 
        + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_WEIGHT 
        + " TEXT NOT NULL, " + KEY_WAIST + " TEXT NOT NULL, " 
        + KEY_CHEST + " TEXT NOT NULL, " + KEY_LEGS 
        + " TEXT NOT NULL, " + KEY_ARMS + " TEXT NOT NULL, " 
        + KEY_DATE + " TEXT NOT NULL);"); 

     } 

     @Override 
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
      db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE); 
      onCreate(db); 

     } 
    } 

    public Stats(Context c) { 
     ffContext = c; 
    } 

    public Stats open() throws SQLException { 
     ffHelper = new DbHelper(ffContext); 
     ffDatabase = ffHelper.getWritableDatabase(); 
     return this; 

    } 

    public void close() { 
     ffHelper.close(); 

    } 

    public long createEntry(String weight, String waist, String chest, String legs, String arms) { 
     SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
     Date date = new Date(); 
     ContentValues cv = new ContentValues(); 
     cv.put(KEY_WEIGHT, weight); 
     cv.put(KEY_WAIST, waist); 
     cv.put(KEY_CHEST, chest); 
     cv.put(KEY_LEGS, legs); 
     cv.put(KEY_ARMS, arms); 
     cv.put("date_created", dateFormat.format(date)); 
     return ffDatabase.insert(DATABASE_TABLE, null, cv); 

    } 

    public String getData() { 
     String[] columns = new String[] { KEY_ROWID, KEY_WEIGHT, KEY_WAIST, KEY_CHEST, KEY_LEGS, KEY_ARMS, KEY_DATE }; 
     Cursor c = ffDatabase.query(DATABASE_TABLE, columns, null, null, null, 
       null, null); 
     String result = ""; 
     int iRow = c.getColumnIndex(KEY_ROWID); 
     int iWeight = c.getColumnIndex(KEY_WEIGHT); 
     int iWaist = c.getColumnIndex(KEY_WAIST); 
     int iChest = c.getColumnIndex(KEY_CHEST); 
     int iLegs = c.getColumnIndex(KEY_LEGS); 
     int iArms = c.getColumnIndex(KEY_ARMS); 
     int iDate = c.getColumnIndex(KEY_DATE); 
     for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) { 
      result = result + c.getString(iRow) + " " + c.getString(iWeight) 
        + " " + c.getString(iWaist) 
        + " " + c.getString(iChest) 
        + " " + c.getString(iLegs) 
        + " " + c.getString(iArms) 
        + " " + c.getString(iDate)+ "\n"; 

     } 

     return result; 
    } 
} 

显然被提及任何时间日期是我尝试添加这个额外的功能。

Answer 1

你可以把日期就像在数据库中的字符串，但该字符串必须有良好的格式。 SQLite的是：

YYYY-MM-dd 
YYYY-MM-dd hh:mm 
YYYY-MM-dd hh:mm:ss 
YYYY-MM-dd hh:mm:ss.sss 
YYYY-MM-DDThh:mm 
YYYY-MM-DDThh:mm:ss 
YYYY-MM-DDThh:mm:ss.sss 
hh:mm 
hh:mm:ss 
hh:mm:ss.sss 

像约恩写，你可以转换日期字符串：

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 

String dateForinsert = dateFormat(new GregorianCalendar(2013, GregorianCalendar.MAY, 5).getTime()); 

“现在，” 你可以用设置：

String dateForinsert = dateFormat(new GregorianCalendar().getTime());