Lets say I have a table with columns A , B , C , D and I want to do a match on column A and C
I see that you can either match a single column or all column in sqlite ie
- match column A
select * from table where A match 'cat'
- match all columns
select * from table where table match 'cat'
Is it possible to match开发者_运维知识库 only columns A and C? If not, how do you guys get around this?
Thanks for your suggestion!
I don't think you can use multiple MATCH operators in a single FTS query. Use column_name:target_term to search multiple columns using one full text search.
SELECT * FROM table WHERE table MATCH 'A:cat OR C:cat'
http://www.sqlite.org/fts3.html#termprefix
Instead of specifying which columns to match to, you can specify the entire table to match to. For example:
-- Example schema
CREATE VIRTUAL TABLE mail USING fts3(subject, body);
-- Example table population
INSERT INTO mail(docid, subject, body) VALUES(1, 'software feedback', 'found it too slow');
INSERT INTO mail(docid, subject, body) VALUES(2, 'software feedback', 'no feedback');
INSERT INTO mail(docid, subject, body) VALUES(3, 'slow lunch order', 'was a software problem');
-- Example queries
SELECT * FROM mail WHERE subject MATCH 'software'; -- Selects rows 1 and 2
SELECT * FROM mail WHERE body MATCH 'feedback'; -- Selects row 2
SELECT * FROM mail WHERE mail MATCH 'software'; -- Selects rows 1, 2 and 3
SELECT * FROM mail WHERE mail MATCH 'slow'; -- Selects rows 1 and 3
For the multiple column condition using MATCH use UNION for the 'OR' and use INTERSECT for the 'AND'
SELECT * FROM TBL_VIRTUAL_APPOINTMENT WHERE PATIENT_PREFIX MATCH 'D*'
UNION
SELECT * FROM TBL_VIRTUAL_APPOINTMENT WHERE patient_first_name MATCH 'K*'
Using sub-queries as workaround:
OR
equivalent query, like a MATCH 'cat' OR c MATCH 'cat'
:
SELECT * FROM table
WHERE ROWID IN (
SELECT ROWID FROM table WHERE a MATCH 'cat'
UNION
SELECT ROWID FROM table WHERE b MATCH 'cat'
);
AND
equivalent query, like a MATCH 'cat' AND c MATCH 'cat'
:
SELECT * FROM table WHERE ROWID IN (
SELECT ROWID FROM table WHERE a MATCH 'cat'
AND ROWID IN (
SELECT ROWID FROM table WHERE b MATCH 'cat'
)
);
You can concatenate columns using the || operator:
SELECT * FROM table WHERE a || b MATCH 'cat'
I'm not sure about the MATCH function in SQLite though, I think it will usually throw an exception (see http://www.sqlite.org/lang_expr.html#match).
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