openGauss每日一练第20天 | 全文检索

1.用tsvector @@ tsquery和tsquery @@ tsvector完成两个基本文本匹配

SELECT to_tsvector('Peppa and george love jumping in muddy puddles') @@ to_tsquery('peppa & george') AS RESULT;
SELECT to_tsquery('peppa & george') @@ to_tsvector('Peppa and george love jumping in muddy puddles') AS RESULT;

2.创建表且至少有两个字段的类型为 text类型，在创建索引前进行全文检索

CREATE SCHEMA eason;
CREATE TABLE eason.eason(id int, body text, title text, last_mod_date date);
INSERT INTO eason.eason VALUES(1, 'China, officially the People''s Republic of China(PRC), located in Asia, is the world''s most populous state.', 'China', '2010-1-1'),(2, 'America is a rock band, formed in England in 1970 by multi-instrumentalists Dewey Bunnell, Dan Peek, and Gerry Beckley.', 'America', '2010-1-1'),(3, 'England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west.', 'England','2010-1-1');

SELECT id, body, title FROM eason.eason WHERE to_tsvector(body) @@ to_tsquery('america');
SELECT title FROM eason.eason WHERE to_tsvector(title || ' ' || body) @@ to_tsquery('china & asia');

3.创建GIN索引

CREATE INDEX eason_idx_1 ON eason.eason USING gin(to_tsvector('english', body));

4.清理数据

drop schema eason cascade;