4. Processing JSONArray Given the above JSON, what if we wish to find out the names of all our customers? In other words, given a key, “name” in our example, how can we go about finding all the values mapped to that key in a given JSON array? As we know, a JSONArray is a...
(); // ways to express the empty object {} json empty_object_implicit = json({}); json empty_object_explicit = json::object(); // a way to express an _array_ of key/value pairs [["currency", "USD"], ["value", 42.99]] json array_not_object = json::array({ {"currency",...
-- 格式: JSON_ARRAY([val[, val] ...]) -- 使用JSON_ARRAY()函数创建数组 : [1, "abc", null, true, "08:09:38.000000"] insert into users(json_data) values(JSON_ARRAY(1, "abc", null, true,curtime())); insert into users(info) values(JSON_ARRAY(1, "abc", null, true,curtime(...
The JSON_VALUE can only return a single scalar value. If you have an array of a nested object that you want to extract, then you must resort to the JSON_QUERY function. How effective is it to query over JSON data? Let’s do some tests. ...
* $key|#key|$int * key * * array|key : is illegal * key|$ : is illegal * key|# : is illegal * key|key : is illegal * @return */ public String getJsonText(String json, String selector){ JSONObject jo = null; JSONArray ja = null; String jsonText = ""; String item =...
(Base): __tablename__ = 'my_table' id = Column(Integer, primary_key=True) data = Column(ARRAY(JSONB)) # 执行like查询 query = session.query(MyModel).filter( func.jsonb_array_elements_text(MyModel.data).like('%查询条件%') ) results = query.all() # 输出结果 for result in ...
Northwind.Categories.FindByCategoryID(categoryID).GetProductsRows(); // Load the names into a string array string[] productNames = new string[rows.Length]; for (int i = 0; i < rows.Length; i++) { productNames[i] = rows[i].ProductName; } // Serialize the string array as JSON ...
"array": [ 1, 2, 3 ], "boolean": true, "color": "gold", "null": null, "number": 123, "object": { "a": "b", "c": "d" }, "string": "www.wdbyte.com" } Jackson 介绍 Jackson 和 FastJson 一样,是一个 Java 语言编写的,可以进行 JSON 处理的开源工具库,Jackson 的使用非常...
CREATE TABLE orders ( id INT AUTO_INCREMENT PRIMARY KEY, order_info JSON ); INSERT INTO `orders` VALUES (1,'{"price": 20.00, "status": "shipped"}'); 在这个表中,我们有一个名为orders的表,包含了以下列: id:订单ID,自增主键。 order_info:存储订单信息的JSON字段。示例数据可能包括订单号、...
What if we want to get all the country names? A new friend -keys- is key in this situation. 🗝 cat test.json | jql '(elem "countries" (elem (keys) (elem "name")))' [ "Poland", "United States", "Germany" ] It returns an array of all the keys of the given collection. Fi...