Question

如何在下面的特定时间之后进行返回作业总数的查询是我的sqllite表我现在正在使用Java获取当前时间如何进行查询，这会在特定时间后返回我的作业总数???

  private static final String TABLE_COMPLETED_JOBS = "jobs";

String CREATE_COMPLETED_TABLE = "CREATE TABLE " + TABLE_COMPLETED_JOBS
            + "(" + KEY_COMPID + " INTEGER PRIMARY KEY," + KEY_TIMEJOB
            + " TEXT,"   + KEY_PICK + " TEXT," + KEY_DEST + " TEXT,"
            + KEY_FARE + " TEXT,"
            + KEY_TIMEWEEK + " DateTime" + ")";






            String selectQuery = "SELECT  * FROM " + TABLE_COMPLETED_JOBS + " ORDER BY 
             "+KEY_TIMEWEEK+" ; 

               String mydate =  

      java.text.DateFormat.getDateTimeInstance().format(Calendar.getInstance().getTime());

Answer 1

假设您编写的查询有效：

String selectQuery = "SELECT  * FROM " + TABLE_COMPLETED_JOBS + " ORDER BY 
         "+KEY_TIMEWEEK+" ;

在执行数据库操作的databaseHandler类中，您可以使用游标来获取计数：

db = this.getReadableDatabase();
Cursor c = db.rawQuery(selectQuery);
int counter;

if(c != null) {
    counter = c.getCount();
}

c.close();
return counter;

因此：如果counter=0表示没有提取记录，而counter>0表示有记录。

希望有所帮助！

Answer 2

这是查询。

SELECT COUNT(*)
FROM jobs
WHERE KEY_TIMEWEEK > myDate

此处，KEY_TIMEWEEK应为列的名称，myDate应为yyyy-MM-dd格式的日期。您可以像这样格式化日期：

SimpleDateFormat dbDateFormat = new SimpleDateFormat("yyyy-MM-dd");

Calendar c = Calendar.getInstance();
String myDate = dbDateFormat.format(c.getTime);

这将以yyy-MM-dd格式返回当前系统日期

Answer 3

int myCount = getData();

Handler handle = new Handler();

handle.postDelayed(new Runnable() 
           {    
             @Override
             public void run() 
             {      
               "the code to be exec."
             }
           }, delayTimeInMilliseconds);

         }

public void getData(){

db = this.getReadableDatabase();
Cursor c = db.rawQuery(selectQuery);
int counter;

if(c != null) {
    counter = c.getCount();
}

c.close();
return counter;


}

只需在处理程序延迟时间内以毫秒为单位添加时间，即可获得所需的输出。

谢谢！

选择在特定时间后返回作业数的查询

3 个答案: