Postgresql full text search for similar words

问题

Trying to implement postgresql full text search example by following these steps;

I have created a table:

CREATE TABLE posts
(
id serial primary key,
content varchar(255),
tags varchar(255),
title varchar(255)
);

Altered the table to have a column of type TSVECTOR

ALTER TABLE posts ADD COLUMN searchtext TSVECTOR;

Created a trigger to store data in searchtext column:

CREATE TRIGGER ts_searchtext BEFORE INSERT OR UPDATE ON posts FOR EACH ROW EXECUTE PROCEDURE tsvector_update_trigger('searchtext', 'english', 'title', 'content', 'tags')

I have inserted a row:

insert into posts(content,tags,title) values('once upon a time I had a fat friend','friend, fat','Fat Boy');

Value under searchtext column is:

"'boy':2 'fat':1,10,13 'friend':11,12 'time':6 'upon':4"

Now, when I run query:

SELECT * FROM posts where searchtext @@ to_tsquery('english','fot');

It returns 0 rows.

So, basically I am looking for a solution where "fot" should have been matched against "fat" or we can say looking for result based on matched letters out of word.

or if we run:

SELECT * FROM posts where searchtext @@ to_tsquery('english','frend');

It should match against "friend". As per documentation of postgresql I think it will be done with the help of dictionaries. But now sure which .dict and .affix file should I use. Can anyone help me with more understanding on this.

回答1:

Try with plainto_tsquery function:

SELECT * FROM posts WHERE searchtext @@ plainto_tsquery('english frend');

来源：https://stackoverflow.com/questions/41034698/postgresql-full-text-search-for-similar-words