Oracle±Ê¼Ç

Oracle µÄ´úÂë±íʾ¼°ÊÂÀý
 
1.  select + xxx + from + xxx   //²éѯÓï¾ä  xxx ±íʾһ¸ö±í  
     Select  *  from  + xxx   // * ±íʾһ¸öÁбíÖÐËùÓеÄÄÚÈÝ
 
  Àࣺ 1£©//  select * from country
 
     2£©//  select vLastName, vFirstName from externalcandidate
 
       “--”±íʾµ¥ÐÐ×¢ÊÍ
      “/*  ...   */ ”±íʾ¶àÐÐ×¢ÊÍ
2.  desc + xxx   // ²é¿´±íµÄ½á¹¹  recruit
   desc externalcandidate
3.  select cCountryCode "±àºÅ",cCountry "¹ú¼Ò" from country; //°Ñ±êÌâÃû×Ö»»ÁË
 
4. select distinct cCity from externalcandidate
   ¼ÓÁ˸ödistinct£¬±íʾûÓÐÖظ´µÄÁË£¬Öظ´ÏÔʾһ¸ö¡£Èç¹ûÊÇÁ½ÁеĻ°ÓÐÁ½¸ö¶¼ÊÇÖظ´µÄ»°£¬¾Í±£ÁôÒ»¸ö
 
   select distinct cCity,CState from college 
 
 
5.ÔËËã·û
  and
  or
  not
  ||     Á¬½ÓÁ½¸ö×Ö·û´®£¬°ÑÁ½ÁеÄÊý¾ÝºÏµ½Ò»ÆðÈ¥ÁË
      
  È磺select vLastName || vFirstName from externalcandidate
            //°ÑÁ½ÁеÄÊý¾ÝºÏÆðÀ´µÄ±êÌâÃû×Ö»»ÁË
    select vLastName || vFirstName "name" from externalcandidate
            //°ÑÁ½ÁеÄÊý¾ÝºÏÆðÀ´Ö®¼ä¼ÓÒ»¸öµã
             select vLastName ||  '.' ||vFirstName "name" from externalcandidate
             //°ÑÁ½ÁеÄÊý¾ÝºÏÆðÀ´Ö®¼ä¼ÓÒ»¸ö×Ö·û´®
             select vLastName || 'von' ||vFirstName "name" from externalcandidate
 
6.   //°ÑÁгöµÄÊý¾Ý³ËÉÏ5µÄ½á¹ûÊǶàÉÙ
     select nAnnualsalary * 5 from An