How do I create sql query for searching partial matches?

问题

I have a set of items in db .Each item has a name and a description.I need to implement a search facility which takes a number of keywords and returns distinct items which have at least one of the keywords matching a word in the name or description.

for example I have in the db ,three items

1.item1 : 
    name : magic marker
    description: a writing device which makes erasable marks    on whiteboard

2.item2:
    name: pall mall cigarettes
    description: cigarette named after a street in london

3.item3:
    name: XPigment Liner
    description: for writing and drawing

A search using keyword 'writing' should return magic marker and XPigment Liner

A search using keyword 'mall' should return the second item

I tried using the LIKE keyword and IN keyword separately ,.. For IN keyword to work,the query has to be

SELECT DISTINCT FROM mytable WHERE name IN ('pall mall cigarettes')

but

SELECT DISTINCT FROM mytable WHERE name IN ('mall')

will return 0 rows

I couldn't figure out how to make a query that accommodates both the name and description columns and allows partial word match..

Can somebody help?

update:

I created the table through hibernate and for the description field, used javax.persistence @Lob annotation.Using psql when I examined the table,It is shown

...
 id           | bigint                      | not null
 description  | text                        |  
 name         | character varying(255)      | 
...

One of the records in the table is like,

id | description | name 
21 | 133414      | magic marker

回答1:

First of all, this approach won't scale in the large, you'll need a separate index from words to item (like an inverted index).

If your data is not large, you can do

SELECT DISTINCT(name) FROM mytable WHERE name LIKE '%mall%' OR description LIKE '%mall%'

using OR if you have multiple keywords.

回答2:

This may work as well.

SELECT * 
FROM myTable
WHERE CHARINDEX('mall', name) > 0
  OR CHARINDEX('mall', description) > 0

来源：https://stackoverflow.com/questions/7172947/how-do-i-create-sql-query-for-searching-partial-matches

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