How to search if whole word exists in a String in Postgres

Question

I have a table with a column field that has values like Samsung Phone.

My question is how can I get this row if I search for a string \"Samsung\" or \"phone

Answer 1

The following solutions are tested in PostgreSQL 9.6.

You may use the \y word boundary and a grouping construct with alternation operator separating all possible alternatives:

where title ~* '\y(?:Samsung|phone)\y'

Or, case insensitively:

where title ~* '\y(?:Samsung|phone)\y'

See the PostgreSQL demo.

Note that \y is not the right approach when the first or last char are not word chars. E.g. you want to search for #samsung or phone#. Then, consider using unambiguous word boundaries:

where title ~* '(?

Here, the (? negative lookbehind fails the match if there is a non-alnum and no _ char immediately to the left of the current position, and the (?!\w) is a negative lookahead fails the match if there is a non-alnum and no _ char immediately to the right of the current position. Equivalent for testing if there is a match in where clause is:

where title ~* '(\W|^)(?:#samsung|phone#)(\W|$)'

See another PostgreSQL demo online:

CREATE TABLE mmytable
    (title character varying)
;

INSERT INTO mmytable
    (title)
VALUES
    ('#Samsung Co.'),
    ('They have a phone#'),
    ('Uncle Sam phoned him')
;

select * from mmytable where title ~* '(?

Also, consider whitespace boundaries when you need to match only in between whitespace characters or start/end of string:

where title ~* '(?