问题
When using the wildcard character in combination with a dot in a text search, my query does not find the matching row.
For example:
CREATE TABLE MY_TABLE( ITEM_NUMBER VARCHAR2(50 BYTE) NOT NULL);
INSERT INTO MY_TABLE (ITEM_NUMBER) VALUES ('1234.1234');
create index TIX_ITEMNO on MY_TABLE(ITEM_NUMBER) indextype is ctxsys.context;
I want to find the row in MY_TABLE where ITEM_NUMBER column is '1234.1234'
This does find the row:
SELECT * FROM MY_TABLE
WHERE CONTAINS(ITEM_NUMBER, '%1234') > 0
This does not find the row:
SELECT * FROM MY_TABLE
WHERE CONTAINS(ITEM_NUMBER, '%.1234') > 0
I do not understand why, since according to Oracle the dot is not a special character that has to be escaped.
How do I have to handle this situation?
回答1:
This is because your default lexer is treating the period as a word separator.
Initial setup:
create table my_table(item_number varchar2(50 byte) not null);
insert into my_table values ('1234.1234');
create index my_index on my_table (item_number)
indextype is ctxsys.context;
This gets the behaviour you see:
SELECT * FROM MY_TABLE
WHERE CONTAINS(ITEM_NUMBER, '%1234') > 0;
--------------------------------------------------
1234.1234
SELECT * FROM MY_TABLE
WHERE CONTAINS(ITEM_NUMBER, '%.1234') > 0;
no rows selected
If you add a lexer that defines PRINTJOINS to include the period:
drop index my_index;
begin
ctx_ddl.create_preference('my_lexer', 'BASIC_LEXER');
ctx_ddl.set_attribute('my_lexer', 'PRINTJOINS', '.');
end;
/
create index my_index on my_table (item_number)
indextype is ctxsys.context
parameters ('lexer my_lexer');
then it behaves the way you want:
SELECT * FROM MY_TABLE
WHERE CONTAINS(ITEM_NUMBER, '%.1234') > 0;
ITEM_NUMBER
--------------------------------------------------
1234.1234
Read more about text indexing elements.
回答2:
I think you wanted
SELECT * FROM MY_TABLE
WHERE ITEM_NUMBER like '%.1234'
来源：https://stackoverflow.com/questions/37885328/query-with-wildcard-and-dot-not-matching-data-with-oracle-text-index