创建全文搜索索引:使用CREATE INDEX语句配合GIN或GiST索引方法和全文搜索数据类型(如tsvector)来创建索引。 填充文本向量:将文本数据转换为tsvector格式,这通常通过to_tsvector函数完成。 构建查询:使用to_tsquery函数将用户的查询字符串转换为查询向量(tsquery),然后使用全文搜索操作符(如@@)来执行搜索。 示例 假设有一个...
CREATE INDEX ON t_document USING gin(to_tsvector('pg_catalog.french', title)); You will have to rewrite the CONTAIN() clause using to_tsvector(), example: SELECT id,title FROM t_document WHERE to_tsvector(title)) @@ to_tsquery('search_word'); To force Ora2Pg to create an extra ...
1 mydb=# INSERT INTO test_tsvector (name,raw,vector) VALUES ('annie','loves dancing',to_tsvector('Loves Dancing')); mydb=# SELECT * FROM test_tsvector WHERE vector @@ to_tsquery('dancing'); name | raw | vector ---+---+--- mary | love dancing | 'danc':2 'love':1 annie ...
array_to_string可以把数组变成字符串。比如在需要将数组中的某个值与某个字符串做模糊匹配的时候,这个函数就可以派上用场 -- 数组转换字符串,用逗号分隔,null直接省略 select array_to_string(ARRAY[1, 2, 3, NULL, 5], ',') -- null用*代替 select array_to_string(ARRAY[1, 2, 3, NULL, 5], ...
2. city_id int not null,3. logdate date not null,4. peaktemp int,5. unitsales int 6. ) PARTITION BY RANGE (logdate);7.8. CREATE TABLE measurement_y2006m02 PARTITION OF measurement 9. FOR VALUES FROM ('2006-02-01') TO ('2006-03-01');分区表更具体的⼀些变化如下：PostgreSQL11...
(to_tsvector('simple', coalesce("positions"."title"::text, ''))) @@ (to_tsquery('simple', ''' ' || 'CUSTOMER' || ' ''') && to_tsquery('simple', ''' ' || 'SERVICE' || ' ''') && to_tsquery('simple', ''' ' || 'ASSOCIATE' || ' '''))) OR ((coalesce("...
def byDistance(point: Point, distance: Int) = tests .filter(r => r.location.dWithin(point.bind, distance.bind)) .map(t => t) // will generate sql like: // select id, text, ts_rank(to_tsvector(text), to_tsquery(?)) // from test where to_tsvector(text) @@ to_tsquery(?) /...
are items accompanied by their frequencies, so we need to do some reasoning before we can construct the result. Say we have an item I with count f (taken from our D structure). The total number of entries is N. The question would be: what would be the ...
其中to_tsvector和to_tsquery中第一个参数用于指定全文检索的分词语言设置,一般可省略,语句如下: SELECT title FROM web WHERE to_tsvector(body) @@ to_tsquery('friend'); 1.5创建索引 gist 和 gin的索引类型,这两种索引都能用在提高全文检索的速度,注意全文检索不一定非要使用索引,但是当一个字段被固定规律搜...
PostgreSQL 提供了专门的全文检索类型tsvector和查询表达式类型tsquery,以及一套完整的全文检索框架,包括词典管理、文本解析、查询构建等功能。MySQL 的全文检索功能相对较弱,直到 MySQL 5.6 才引入了全文索引,但其功能和灵活性不及 PostgreSQL。 其他特殊类型: