FETCH

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��ϴ�Ϣ��־��FETCH�Ϥ��Ѥ��ޤ�� ֤��䤤��碌�η�̤��Ƭ�Ԥ��Ǥ�դ��ιԡ��̤κǽ��Ԥθ��뤳�Ȥ��Ǥ��ޤ�� ΰ��֤��Ƭ�Ԥ��ؤ��Ƥ��ޤ�� Ԥ��Ф��塢��ΰ��֤ϺǶ�˼��Ф��Ԥ�ؤ��ޤ�� FETCH��Ѳ�ǽ�ʹԤν��ޤ�ã��ΰ��֤Ϻǽ��Ԥθ�򡢤⤷��Фξ��Ƭ�Ԥ��ؤ�³��ޤ�� FETCH ALL�⤷��FETCH BACKWARD ALL�Ǥϡ��ΰ��֤Ͼ�˺ǽ��Ԥθ塢�⤷��ϡ��Ƭ�Ԥ��ؤ��Ƥ��ޤ��

NEXT��PRIOR��FIRST��LAST��ABSOLUTE��RELATIVE��Ǥϡ��Ŭ�ڤ˰�ư��塢1�ĤιԤ��Ф��ޤ�� Ԥ�¸�ߤ��ʤ��硢��η�̤��֤��졢��Ϥ��Τޤ��Ƭ�Ԥ��ǽ��Ԥθ��ؤ�³��ޤ��

FORWARD��BACKWARD��Ѥ��Ǥϡ��ιԤ��⤷��ϸ��˼��Ф��ΰ��֤ϺǸ�˼��Ф��Ԥ�ؤ��ޤ�� (count��Ѳ�ǽ�ʹԿ��ۤ��Ƥ��ϡ��Ԥθ�/��ؤ��ޤ��)

RELATIVE 0��FORWARD 0��BACKWARD 0��ơ��ư��뤳��̵��ߤιԤ��Ф��ޤ�� Ĥޤꡢ�Ǥ�Ƕ��Ф��Ԥ��ټ��Ф��ޤ�� 뤬��Ƭ�Ԥ��ǽ��Ԥθ�ˤʤ��С��ޤ�� 뤬��Ƭ�Ԥ��ǽ��Ԥθ�ˤ��С��Ԥ��֤��ޤ��

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direction

direction�ϡ��Ф��ȼ��Ф��Կ��ޤ�� ʲ��Τ��줫��뤳�Ȥ��Ǥ��ޤ��

NEXT: ��ιԤ��Ф��ޤ�� ϡ�direction��ά��줿��Υǥե��ȤǤ��
PRIOR: ��ιԤ��Ф��ޤ��
FIRST: �䤤��碌��Ƭ�Ԥ��Ф��ޤ�� (ABSOLUTE 1 ��Ʊ��Ǥ��)
LAST: �䤤��碌�κǽ��Ԥ��Ф��ޤ�� (ABSOLUTE -1��Ʊ��Ǥ��)
ABSOLUTE count: �䤤��碌��count��ܤιԤ��Ф��ޤ�� ⤷��count��ʤ�С��꤫��abs(count)��ܤιԤ��Ф��ޤ�� count��ϰϳ��ξ�硢��֤��Ƭ�Ԥ��ǽ��Ԥθ�ˤʤ�ޤ�� äˡ�ABSOLUTE 0�Ǥ��Ƭ�Ԥ��ؤ��褦�ˤʤ�ޤ��
RELATIVE count: ��߰��֤��count��ܤιԤ��Ф��ޤ�� count��ξ�硢��߰��֤��abs(count)��ιԤ��Ф��ޤ�� RELATIVE 0�ϡ��⤷��ߤιԤ��С��ιԤ��ټ��Ф��ޤ��
count: ��count�Ԥ��Ф��ޤ�� (FORWARD count��Ʊ��Ǥ��)
ALL: �Ĥ�Ԥ��Ƽ��Ф��ޤ�� (FORWARD ALL��Ʊ��Ǥ��)
FORWARD: ��ιԤ��Ф��ޤ�� (NEXT��Ʊ��Ǥ��)
FORWARD count: ��count�Ԥ��Ф��ޤ�� FORWARD 0�ϸ��ߤιԤ��ټ��Ф��ޤ��
FORWARD ALL: �Ĥ�Ԥ��Ƽ��Ф��ޤ��
BACKWARD: ��ιԤ��Ф��ޤ�� (PRIOR��Ʊ��Ǥ��)
BACKWARD count: ��count�Ԥ�(��)��Ф��ޤ�� BACKWARD 0�ϸ��ߤιԤ��ټ��Ф��ޤ��
BACKWARD ALL: ��Ƥ��ιԤ�(��)��Ф��ޤ��

count

��Ф��֤�Կ��ꤹ��count�ϡ��ǡ��դ��뤳�Ȥ��Ǥ��ޤ�� FORWARD��BACKWARD�ξ�硢��count�ϡ�FORWARD��BACKWARD�ΰ�̣��ѹ��뤳�Ȥ�Ʊ��Ǥ��

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FETCH count

count��(0��ޤ�)��Ф��Կ��Ǥ�� psql�ϼ��Ф��Կ��ɽ��ޤ��Τǡ�psql�Ǥϡ��Υ��ޥ�ɥ��ϼºݤˤ�ɽ��ʤ��Ȥ��դ��Ƥ��

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FETCH NEXT�⤷��FETCH FORWARD�ʳ��μ��FETCH��Ѥ��褦�Ȥ��硢��Υ��SCROLL��ץ��դ��ʤ��Фʤ�ޤ�� ñ��䤤��碌�Ǥϡ�PostgreSQL�ˤ�ꡢ��뤬SCROLL�դ��Ƥ��ʤ��Ƥ��μ��Ф��Ԥ��Ȥ��Ǥ��ޤ��ư��˰�¸��٤��ǤϤ��ޤ�� 뤬NO SCROLL�դ��줿��ϡ��μ��Ф��Ԥ��Ȥ��Ǥ��ޤ��

��Ū�ʻ��ˤ��Ԥؤΰ�ư��١�ABSOLUTE�ˤ��Ф��Ϲ�®�ǤϤ��ޤ�� μ��Ǥϡ�ɬ��֤ιԤ��ư��뤫��Ǥ�� л��ˤ��Ф��Ǥϡ��äȰ��ޤ�� ǽ��Ԥ��դ��뤿��ɬ��Ǹ�ޤ��䤤��碌��ɤ߼��ʤ��Фʤ餺��ơ��θ�˺ǽ��Ԥ��˰�ư��ޤ��Ǥ�� (FETCH ABSOLUTE 0��Ѥ��)�䤤��碌��Ƭ��ˤϹ�®�Ǥ��

��ߡ�PostgreSQL�Ǥϡ��Ѥ��ǡ��ι��򥵥ݡ��Ȥ��Ƥ��ޤ��

DECLARE��Ѥ��ƥ��ޤ�� ǡ��Ф��˥��֤��ѹ��MOVE��Ѥ��Ƥ��

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BEGIN WORK;

-- ������������ꤷ�ޤ���
DECLARE liahona SCROLL CURSOR FOR SELECT * FROM films;

-- liahona�������뤫��ǽ��5�Ԥ���Ф��ޤ���

FETCH FORWARD 5 FROM liahona;

 code  |          title          | did | date_prod  |   kind   |  len
-------+-------------------------+-----+------------+----------+-------
 BL101 | The Third Man           | 101 | 1949-12-23 | Drama    | 01:44
 BL102 | The African Queen       | 101 | 1951-08-11 | Romantic | 01:43
 JL201 | Une Femme est une Femme | 102 | 1961-03-12 | Romantic | 01:25
 P_301 | Vertigo                 | 103 | 1958-11-14 | Action   | 02:08
 P_302 | Becket                  | 103 | 1964-02-03 | Drama    | 02:28

-- ���ιԤ���Ф��ޤ���
FETCH PRIOR FROM liahona;

 code  |  title  | did | date_prod  |  kind  |  len
-------+---------+-----+------------+--------+-------
 P_301 | Vertigo | 103 | 1958-11-14 | Action | 02:08

-- ����������Ĥ����ȥ�󥶥�������λ���ޤ���
CLOSE liahona;
COMMIT WORK;

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CLOSE, DECLARE, MOVE

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