问题描述
我有一个json对象,其中包含账单下的产品列表.我想为其编写一个mysql函数,该函数从json读取数据并对其进行一个接一个的迭代,并将相同的数据插入到product和bill表中.
I have a json object which has list of products under a bill. I want to write a mysql function for it which reads the data from the json and iterates over it one by one and inserts the same data to product and bill tables.
这是我的json对象
{"billNo":16,"date":"2017-13-11 09:05:01","customerName":"Vikas","total":350.0,"fixedCharges":100,"taxAmount":25.78,"status":paid,"product":[{"productId":"MRR11","categoryId":72,"categoryName":"Parker Pen","cost":200,"quantity":2,"log":{"supplierId":"725","supplierName":"Rihant General Stores"}},{"productId":"MRR12","categoryId":56,"categoryName":"Drawing Books","cost":150,"quantity":3,"log":{"supplierId":"725","supplierName":"Rihant General Stores"}}]}
这里我有一个mysql函数,它从JSON读取数据
Here I have a mysql function which reads the data from the JSON
CREATE DEFINER=`mydb`@`%` FUNCTION `raiseOrder`(dataObject Json)
RETURNS bigint(11)
BEGIN
DECLARE billNo BIGINT(11) DEFAULT NULL;
DECLARE customerName VARCHAR(64);
DECLARE date datetime DEFAULT NOW();
DECLARE total Float(12,2);
DECLARE taxamt Float(12,2);
DECLARE fixedCharges Float(12,2);
DECLARE products json;
DECLARE productId bigint(15) DEFAULT NULL;
DECLARE categoryId bigint(11);
DECLARE cost float;
DECLARE categoryName varchar(64);
DECLARE quantity int default 0;
DECLARE supplierId bigint(11);
DECLARE supplierName varchar(128);
SET billNo = (SELECT JSON_EXTRACT(dataObject, "$.billNo"));
SET customerName = (SELECT JSON_EXTRACT(dataObject, "$.customerName"));
SET products = (SELECT JSON_EXTRACT(dataObject, "$.products"));
SET productId = (SELECT JSON_EXTRACT(products, "$[0].productId"));
RETURN 1;
END
现在有这些行
SET products = (SELECT JSON_EXTRACT(dataObject, "$.products"));
SET productId = (SELECT JSON_EXTRACT(products, "$[0].productId"));
我得到内部产品json和第0个产品的ID.但是我想要一种遍历所有产品的方法.
I get the inner products json and the id of the 0th product. But I want a way to iterate over the array of the products.
推荐答案
您可以将WHILE循环与JSON_LENGTH结合使用来实现此目的:
You can use a WHILE loop in conjunction with JSON_LENGTH to achieve this:
DECLARE json, products, product VARCHAR(4000);
DECLARE i INT DEFAULT 0;
SELECT '{"billNo":16,"date":"2017-13-11 09:05:01","customerName":"Vikas","total":350.0,"fixedCharges":100,"taxAmount":25.78,"status":"paid","product":[{"productId":"MRR11","categoryId":72,"categoryName":"Parker Pen","cost":200,"quantity":2,"log":{"supplierId":"725","supplierName":"Rihant General Stores"}},{"productId":"MRR12","categoryId":56,"categoryName":"Drawing Books","cost":150,"quantity":3,"log":{"supplierId":"725","supplierName":"Rihant General Stores"}}]}
' INTO json;
SELECT json->"$.product" INTO products;
WHILE i < JSON_LENGTH(products) DO
SELECT JSON_EXTRACT(products,CONCAT('$[',i,']')) INTO product;
SELECT product;
SELECT i + 1 INTO i;
END WHILE;
尽管,您可能需要做的不仅仅是简单的选择产品";-)
You'll probably need to do more than simply 'SELECT product' though ;-)
注意:5.7.8中添加了MySQL JSON函数,因此您需要首先检查MySQL版本.
NOTE: MySQL JSON functions were added in 5.7.8 so you'll need to check your MySQL version first.
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