JSON Query Syntax and Examples PostgreSQL provides two JSON data types: json (non-validated) and jsonb (binary, optimized for indexing and querying). The jsonb type is generally preferred for querying because it
selectdescription::json->'data'->(JSON_ARRAY_LENGTH(description::json->'data')-1)->0asreadtimefromleanheat.lh_demo_ecl_aggregatedata Examples of json operation(增删改查):fromhere CREATETABLEleanheat.TActivity ( idbigintPRIMARYKEY,--活动idtitlecharactervarying(128)NOTNULL,--活动名称pricepackage ...
PostgreSQL JSON examples Let’s take some examples of storing JSON data in the PostgreSQL database. 1) Storing JSON objects example First, create a new table called products: CREATE TABLE products( id SERIAL PRIMARY KEY, name VARCHAR(255) NOT NULL, properties JSONB ); The products table incl...
POST / HTTP/1.1 Host: postgres.tencentcloudapi.com Content-Type: application/json X-TC-Action: DescribeDBInstanceAttribute <公共请求参数> { "DBInstanceId": "postgres-xxxxxxxx" } 输出示例 {"Response":{"RequestId":"08fdf411-5d39-44f2-8e1d-a58ee60b237d","DBInstance":{"Region":"ap-guangz...
Example 1: Understanding the json_to_recordset() Function To understand the concept behind thejson_to_recordset()function, the following query can be used. SELECT * FROM json_to_recordset( '[{"student_id": 1, "student_name": "Tom", "subjects": ["Chemistry", "Calculus"]}, ...
半结构化数据(如 JSON); 向量数据。 在传统架构中,不同类型的数据往往被存储在不同的系统中: 结构化数据用关系数据库或数仓; 半结构化数据的存储和检索用 NoSQL; 向量检索用向量数据库。 这样的问题是当我们要执行一个 Top 100 推荐任务时,分布在多个系统中的结果很难直接进行 Join 操作,因为性能很差。于是...
We can understand the workings of thejsonb_typeof()function using some examples. Example 1: Understanding the jsonb_typeof() Function in PostgreSQL To learn, how thejsonb_typeof()function works, we can execute the following query:
Examples Seesimplefor similar code to the above. There is an extended example inhuman-1andhuman-2. An example of the simple customizations available by specializing generic functions is shown incustomize.(ql:quickload :postgres-json-examples)will compile all the examples. ...
@app.route('/', methods=['GET'])defindex():print('Request for index page received')restaurants = Restaurant.query.all()returnrender_template('index.html', restaurants=restaurants) 步驟1:在 App Service 頁面中: 從左側功能表中,選取 [監視]> [App Service 記錄]。
The SQL query seems OK at first glance: SELECT (("mymodel"."jsonfield" -> 'subfield'))::text, COUNT("mymodel"."id") AS "id_count" FROM "mymodel" GROUP BY (("mymodel"."jsonfield" -> 'subfield'))::text ORDER BY ("mymodel"."jsonfield" -> 'subfield') ASC ...