是否有任何等价物
mysql_query("SELECT subcategory, COUNT(*) AS subcate FROM database GROUP BY subcategory");
在 Js-Json 中,我可以计算出有多少个独特的子类别并将它们打印在 JSON 数组中,而无需在 mysql_query
中过滤它们?
假设我从数据库中获取了完整的表格
mysql_query("SELECT * FROM database");
然后我将其放入 json_encode($array);
中,然后我可以计算唯一的子类别并从该 JSON 数组打印它们吗?
JSON 数据
[{"category":"fish","subcategory":"angel","name":"angelfish juvenille"},{"category":"fish","subcategory":"angel","name":"angelfish adult"},{"category":"fish","subcategory":"clownfish","name":"clownfish juvenille"},{"category":"fish","subcategory":"clownfish","name":"clownfish adult"]
最佳答案
您需要对数据列表进行简单的归约。您为每个子类别保留一个带有键的对象,该值是具有该特定子类别的元素的数量:
var data = [{"category":"fish","subcategory":"angel","name":"angelfish juvenille"},{"category":"fish","subcategory":"angel","name":"angelfish adult"},{"category":"fish","subcategory":"clownfish","name":"clownfish juvenille"},{"category":"fish","subcategory":"clownfish","name":"clownfish adult"}]
var result= data.reduce((all, element) => {
all[element.subcategory] = (all[element.subcategory] || 0) +1;
return all
}, {});
console.log(result);
关于javascript - MYSQL Count As, Group By, JSON 等效,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/48057960/