SELECT jsonb_array_elements('{"data": [{"name": "John", "age": 30}, {"name": "Jane", "age": 25}]}'::jsonb->'data') AS extracted_value; 在上面的查询中,我们首先将json字符串转换为jsonb类型,并使用->操作符提取名为"data"的键的值。然后,我们使用jsonb_array_elements函数将该值转...
在PostgreSQL中，可以创建一个“GIN”（通用倒排索引）索引来索引JSONB对象中的所有属性，或者可以使用“表达式”索引来在特定JSONB元素上创建索引。CREATE INDEX ccjsonb_path_ops_idx ON cc_jsonb USING GIN (data jsonb_path_ops);SELECT * FROM cc_jsonb WHERE data @> '{"name":"First"}'::jsonbSEL...
WITH RECURSIVE merge_sort AS ( -- 基础情况:只有一个元素的数组是有序的 SELECT id, value FROM your_table WHERE id = (SELECT MIN(id) FROM your_table) UNION ALL -- 递归情况:合并两个有序的子数组 SELECT m1.id, m1.value FROM merge_sort m1 JOIN merge_sort m2 ON m1.id > m2.id WHERE...
SELECT a->>'key' AS key, a->>'value' AS value FROM jsonb_path_query('{"code1": { "obj1": [ { "sample_name": "1", "sample_code": "1", "sample_serial": "01", "parameters": [ { "param1": "param1", "param2": "param2", "param3": "param3", "param4": "param...
包括JSON类型的键值 3、应用场景 Postgres-XL是一个水平可扩展的开源SQL数据库集群,足够灵活,可以处理不同的数据库工作负载: OLTP密集型写入工作负载 MPP架构的并行商业智能系统 操作数据存储 键值存储 GIS地理空间 混合工作负载环境 多租户提供商托管环境
select MAX(a.ts) AS last_complete_datetime,serial_key from mesr.activity a inner join mesr.location l on trim(a.a1) = trim(l.short_workstation) and a.action=11 and l.unit_status_key=30 WHERE a.ts BETWEEN '2024-04-01 00:00:00' AND '2024-04-02 23:59:59' GROUP BY serial_...
SELECT current_setting('block_size')::numeric AS bs, 23 AS hdr, 8 AS ma ), no_stats AS ( -- screen out table who have attributes -- which dont have stats, such as JSON SELECT table_schema, table_name, n_live_tup::numeric AS est_rows, pg_table_size(relid)::numeric AS table_...
as newtable ('||rowc||' varchar,'||columnlist||')';stmt=E' select array_to_json(array_agg(row_to_json(t))) from ('||dynsql2||') t ';executestmtintoresult;returnresult;end$$ 测试用表结构和数据 -- toy example to show how it works...
You are now connected to database "rundb" as user "postgres". rundb=# CREATE TABLE Person( rundb(# ID INT PRIMARY KEY NOT NULL, rundb(# NAME TEXT NOT NULL, rundb(# AGE INT NOT NULL, rundb(# ADDRESS CHAR(50), rundb(# SALARY REAL ...
let value = match serde_json::from_str::<Vec<f64>>( input.to_str().expect("expect input to be UTF-8 encoded"), ) { Ok(v) => v, Err(e) => { pgrx::error!("failed to deserialize the input string due to error {}", e) ...