分类:数据库


postgresql根据结果集中某字段限定该字段相同值只获取20条


SELECT
T .company_id,
T .business_description_cn,
T .business_scope_cn,
T .company_tag_cn,
T .industry_id,
T .industry,
T .company_name_cn
FROM
(
SELECT
company_id,
business_description_cn,
business_scope_cn,
company_tag_cn,
industry_id,
config."dictionary".name_cn AS industry,
company_name_cn,
ROW_NUMBER() OVER(PARTITION BY industry_id) AS ROW
FROM
company_profile
LEFT JOIN config."dictionary" ON company_profile.industry_id = config."dictionary". ID
WHERE
industry_id IS NOT NULL
AND company_status_id LIKE '2%'
) T WHERE ROW <= 20

postgresql创建简单搜索视图


--创建search_company
CREATE MATERIALIZED VIEW search_company AS SELECT DISTINCT a.company_id,
a.ticker,
a.company_status_id,
a.company_name_cn,
a.company_name_en,
a.company_shortname_cn,
a.company_shortname_en,
b.brand_name,
a.year_founded,
c.name_cn AS company_status_name_cn,
c.name_en AS company_status_name_en
FROM ((company_profile a
LEFT JOIN brand_info b ON (((a.company_id)::text = (b.company_id)::text)))
LEFT JOIN config.dictionary c ON (((a.company_status_id)::text = (c.id)::text)))
WHERE a.company_status_id!='3.3'
ORDER BY a.ticker;

--导入自定义函数(扩展包)
CREATE EXTENSION zhparser;
CREATE TEXT SEARCH CONFIGURATION zhcfg (PARSER = zhparser);
ALTER TEXT SEARCH CONFIGURATION zhcfg ADD MAPPING FOR n,v,a,i,e,l WITH simple;
create extension pg_trgm;
create or replace function record_to_text(anyelement) returns text as $$
select $1::text;
$$ language sql strict immutable;

--创建全文索引
create index idx_search_company_gist on search_company using gist (record_to_text(search_company) gist_trgm_ops);
create index idx_search_company_gin on search_company using gin (record_to_text(search_company) gin_trgm_ops);

--检测索引是否正常
/*+ BitmapScan(search_company idx_search_company_gin) */ select * from search_company where record_to_text(search_company) ~ '经纬' and company_status_id like'3%' limit 99;

同步同一个表中的相关字段


--创建函数

CREATE OR REPLACE FUNCTION updateItemDDL(center_show varchar,item_ddl VARCHAR,table_name varchar,item varchar)
RETURNS
void as $$
UPDATE schema_table set center_show=$1,item_ddl=$2 WHERE "table_name"=$3 AND item=$4 AND "version"='v2';
$$ LANGUAGE 'sql' VOLATILE;

--执行函数

SELECT updateItemDDL(center_show,item_ddl,"table_name",item) from schema_table WHERE "version"='v1' AND item_ddl!='';

查询是否执行成功

SELECT "table_name",item,center_show,item_ddl from schema_table WHERE "version"='v2' AND item_ddl!=''

postgresql某字段存多个id,然后根据id连表查询


--buyer_id即为多id字段,id间通过逗号分隔

SELECT
array_to_json(array_agg(row_to_json(T))) as buyer
FROM
(
SELECT
company_id,
company_name_cn,
company_status_id
FROM
company_profile
WHERE
company_id IN(
SELECT
regexp_split_to_table(buyer_id, ',')
FROM
model_1
)
) T