http://www.itpub.net/thread-1499223-1-1.html
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哪一个PLSQL块执行之后会显示下面的三行数字？
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A
DECLARE TYPE numbers_t IS TABLE OF NUMBER; l_numbers numbers_t := numbers_t (); BEGIN DBMS_OUTPUT.put_line (l_numbers.COUNT); l_numbers.EXTEND (); l_numbers (1) := 100; DBMS_OUTPUT.put_line (l_numbers.COUNT); l_numbers.EXTEND (); DBMS_OUTPUT.put_line (l_numbers.COUNT); END; /
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B
DECLARE TYPE numbers_t IS TABLE OF NUMBER; l_numbers numbers_t := numbers_t (); BEGIN DBMS_OUTPUT.put_line (l_numbers.COUNT); l_numbers.EXTEND (2); l_numbers (1) := 100; DBMS_OUTPUT.put_line (l_numbers.COUNT); l_numbers (2) := 100; DBMS_OUTPUT.put_line (l_numbers.COUNT); END; /
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C
DECLARE TYPE numbers_t IS TABLE OF NUMBER; l_numbers numbers_t := numbers_t (); BEGIN DBMS_OUTPUT.put_line (l_numbers.COUNT); l_numbers.EXTEND (2); l_numbers (1) := 100; l_numbers.DELETE (1); DBMS_OUTPUT.put_line (l_numbers.COUNT); l_numbers (2) := 100; DBMS_OUTPUT.put_line (l_numbers.COUNT); END; /
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D
DECLARE TYPE numbers_t IS TABLE OF NUMBER; l_numbers numbers_t := numbers_t (); BEGIN DBMS_OUTPUT.put_line (l_numbers.COUNT); l_numbers.EXTEND (2); l_numbers (1) := 100; l_numbers.DELETE (1); DBMS_OUTPUT.put_line (l_numbers.COUNT); l_numbers (1) := 200; l_numbers (2) := 100; DBMS_OUTPUT.put_line (l_numbers.COUNT); END; /
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知识点后补
