Oracle 包含对包含“非”字的短语的工作失败

Question

我正在尝试在表中搜索“未放置”之类的短语，其中 col 由“indextype is ctxsys.context”索引

select * from 
table
where contains (col, 'not placed')>0

没有“NOT”字样，搜索工作绝对正常，没有任何问题。

只要在搜索短语中添加“not”，就会引发以下问题 -

ORA-29902: error in executing ODCIIndexStart() routine
ORA-20000: Oracle Text error:
DRG-50901: text query parser syntax error on line 1, column 1  
29902. 00000 -  "error in executing ODCIIndexStart() routine"
*Cause:    The execution of ODCIIndexStart routine caused an error.
*Action:   Examine the error messages produced by the indextype code and
           take appropriate action.

我什至尝试对“not”字使用转义序列，但它无法识别“not”字本身

Answer 1

not 是not 运算符的保留字。您需要转义它以使用contains 搜索此值。为此，请用花括号 {} 将其括起来。

它也是默认停用词之一。这些不包含在索引中。

这将创建一个带有空停止列表的索引。所以它包括每个单词：

create table t (
  c1 varchar2(100)
);

insert into t values ( 'placed' );
insert into t values ( 'not placed' );
insert into t values ( 'something else' );
insert into t values ( 'file is placed in folder' ); 
insert into t values ( 'file is not placed in folder' ); 
commit;

create index i 
  on t ( c1 ) 
  indextype is ctxsys.context
  parameters (
    'stoplist ctxsys.empty_stoplist sync(on commit)'
  );

select * from t 
where  contains (c1, 'placed') > 0;

C1                             
placed                          
not placed                      
file is placed in folder        
file is not placed in folder  

select * from t 
where  contains (c1, 'not placed') > 0;

ORA-29902: error in executing ODCIIndexStart() routine
ORA-20000: Oracle Text error:
DRG-50901: text query parser syntax error on line 1, column 1  

select * from t 
where  contains (c1, '{not} placed') > 0;

C1                             
not placed                      
file is not placed in folder    

但您可能想创建自己的custom stop list。