Oracle Decodeº¯ÊýʹÓü¼ÇÉ
decodeº¯Êý
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decode(expr,search,result[,search,result]..[,search,result][,default])
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SQL> select decode('0','0','true','1','false',null) from dual; --·µ»Øtrue
SQL> select decode('1','0','true','1','false',null) from dual; --·µ»Øfalse
SQL> select decode('2','0','true','1','false',null) from dual; --·µ»Ønull
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----------------------------------------- -------- ----------------------------
SEQ NOT NULL NUMBER(3)
JCXM NUMBER(3)
ZHI NUMBER(3,2)
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SEQ JCXM ZHI
---------- ---------- ----------
11 1 .5
11 2 .21
11 3 .25
12  
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DECLARE
TYPE CourseList IS TABLE OF VARCHAR2(10);
courses CourseList;
BEGIN
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courses := CourseList( 'Biol 4412 ', 'Psyc 3112 ', 'Anth 3001 ');
-- ΪÊý×éÔö¼ÓÒ»¸öÔªËØ£¬Êý×é´óСΪ4£¬Ä©Î²µÄÔªËØΪNULL
courses.EXTEN ......
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SQL> select ascii('A') A,ascii('a') a,ascii('0') zero,ascii(' ') space from dual;
A A ZERO &nbs ......
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