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oracle ±Ê¼Ç VI Ö®Óαê (CURSOR)

 Óαê(CURSOR),ºÜÖØÒª
Óαê:ÓÃÓÚ´¦Àí¶àÐмǼµÄÊÂÎñ
ÓαêÊÇÒ»¸öÖ¸ÏòÉÏÏÂÎĵľä±ú(handle)»òÖ¸Õë,¼òµ¥Ëµ£¬Óαê¾ÍÊÇÒ»¸öÖ¸Õë
1 ´¦ÀíÏÔʽÓαê
  ÏÔʽÓα괦ÀíÐè 4¸ö PL/SQL ²½Öè,ÏÔʾÓαêÖ÷ÒªÓÃÓÚ´¦Àí²éѯÓï¾ä
  (1) ¶¨ÒåÓαê
  ¸ñʽ:  CURSOR cursor_name [(partment[,parameter]...)] IS select_statement;
   ¶¨ÒåµÄÓα겻ÄÜÓÐ INTO ×Ó¾ä
  (2) ´ò¿ªÓαê
   OPEN cursor_name[...];
  PL/SQL ³ÌÐò²»ÄÜÓà OPEN Óï¾äÖØ¸´´ò¿ªÒ»¸öÓαê
  (3)ÌáÈ¡ÓαêÊý¾Ý
   FETCH cursor_name INTO {variable_list | record_variable};
  (4) ¹Ø±ÕÓαê
   CLOSE cursor_name;
  Àý 1 ²éѯǰ 10 ÃûÔ±¹¤µÄÐÅÏ¢  
   declare
    --¶¨ÒåÓαê
    cursor c_cursor is select last_name,salary  from employees where rownum < 11 order by salary;
    v_name employees.last_name%type;
    V_sal employees.salary%type;
 
    begin
      --´ò¿ªÓαê
      open c_cursor;
      -- ÌáÈ¡ÓαêÊý¾Ý
      fetch c_cursor into v_name,v_sal;
       while c_cursor %found loop
             dbms_output.put_line(v_name || ':' || v_sal);
             fetch c_cursor into v_name,v_sal;
        end loop;
  
       --¹Ø±ÕÓαê
       close c_cursor;
   end;
----------------------------------
 Á·Ï°: ÊäÈ벿ÃźŠdep_id,²éѯ¸Ã²¿Ãŵį½¾ù¹¤×Ê : avg_sal,Ô±¹¤¹¤×ÊΪ salary
       Èô salary < avg_sal - 500 ¹¤×ÊÕÇ 500
       Èô avg_sal - 500 <= salary < avg_sal + 500 ¹¤×ÊÕÇ 300
       Èô


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Oracle·ÖÎöº¯ÊýÓ¦ÓÃ(Analytic Functions)

Oracle ·ÖÎöº¯ÊýʹÓýéÉÜ
   ·ÖÎöº¯ÊýÊÇoracle816ÒýÈëµÄÒ»¸öȫеĸÅÄî,ΪÎÒÃÇ·ÖÎöÊý¾ÝÌṩÁËÒ»ÖÖ¼òµ¥¸ßЧµÄ´¦Àí·½Ê½.ÔÚ·ÖÎöº¯Êý³öÏÖÒÔǰ,ÎÒÃDZØÐëʹÓÃ×ÔÁª²éѯ,×Ó²éѯ»òÕßÄÚÁªÊÓͼ,ÉõÖÁ¸´ÔӵĴ洢¹ý³ÌʵÏÖµÄÓï¾ä,ÏÖÔÚÖ»ÒªÒ»Ìõ¼òµ¥µÄsqlÓï¾ä¾Í¿ÉÒÔʵÏÖÁË,¶øÇÒÔÚÖ´ÐÐЧÂÊ·½ÃæÒ²ÓÐÏ൱´óµÄÌá¸ß.ÏÂÃæÎÒ½«Õë¶Ô·ÖÎöº¯ ......

Oracle ÃÜÂëÎļþѧϰ

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oracle ±Ê¼Ç III Ö®´æ´¢¹ý³ÌÓ뺯Êý

DML(Manipulation):Êý¾Ý²Ù×÷ÓïÑÔ
CRUD
DDL(Definition): Êý¾Ý¶¨ÒåÓïÑÔ,Óë±í£¬Ë÷Òý£¬Í¬Òå´ÊÓйØ
create,alter,drop,rename,truncate(Çå¿Õ)
DCL(Control): Êý¾Ý¿ØÖÆÓïÑÔ£¬ÓëȨÏÞÓйØ
grant,revoke
TCL(Transaction Control): ÊÂÎñ¿ØÖÆÓïÑÔ,ÓëÊÂÎñÓйØ
commit,rollback,savepoint
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Oracle ¸ôÀë¼¶±ð

¸ôÀë¼¶±ð£¨isoation level£©
 
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ANSI/ISO SQ92±ê×¼¶¨ÒåÁËһЩÊý¾Ý¿â²Ù×÷µÄ¸ôÀë¼¶±ð£º
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Oracle×Ö·û´®º¯Êý

 1.ASCII 
·µ»ØÓëÖ¸¶¨µÄ×Ö·û¶ÔÓ¦µÄÊ®½øÖÆÊý; 
SQL> select ascii(’A’) A,ascii(’a’) a,ascii(’0’) zero,ascii(’ ’) space from dual; 
A A ZERO SPACE 
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65 97 48 32
2.CHR 
¸ø³öÕ ......
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