Question

我有一些对象想通过reduce进行重组，但是在找出正确的方法方面有些困难。数据如下：

DECLARE @value VARCHAR(max) = NULL

SELECT @value = COALESCE(@value + ';' + ug.unitGroupName, ug.unitGroupName)
FROM unitGroups ug    

SELECT @value as Name, 
       MIN(ue.unitDate) as unitDate, 
       MIN(ue.unitStartTime) as unitStartTime, 
       MIN(ue.unitEndTime)as unitEndTime
FROM unitEvents ue
LEFT JOIN unitGroups ug ON ug.unitID = ue.unitID
LEFT JOIN units u ON ug.unitID = u.unitID
WHERE u.unitYear = 2018
AND ue.eventWeek between '12/1/2018' and '12/7/2018'

我想做的是重组此数组，以便按名称对所有项目进行分组，并对帐户数组进行展平。结果是这样的

[ { name: 'Item', accounts: [ { value: 1 }, { value: 2 }, { value: 3}] },
{ name: 'Item', accounts: [ { value: 1 }, { value: 2 }, { value: 3}] },
{ name: 'Item', accounts: [ { value: 1 }, { value: 2 }, { value: 3}] },
{ name: 'Item2', accounts: [ { value: 1 }, { value: 2 }, { value: 3}] },
{ name: 'Item2', accounts: [ { value: 1 }, { value: 2 }, { value: 3}] },
{ name: 'Item2', accounts: [ { value: 1 }, { value: 2 }, { value: 3}] } ],

我尝试使用以下代码来执行此操作，但是我遇到了问题，并且结构与我所寻找的不完全相同。

[
 {
  name: 'Item',
  accounts: [ { value: 1 }, { value 2 } ] //.. Includes all account objects that had the  name 'Item' 
 },

 {
  name: 'Item 2',
  accounts: [  { value: 1 }, { value: 2 } ] //.. Includes all account object that had the name 'Item2'
 }
]

执行此操作的正确方法是什么？

Answer 1

您可以将分散的数组推入帐户，并在分组后获取对象的值。

var accounts = [{ name: 'Item', accounts: [{ value: 1 }, { value: 2 }, { value: 3 }] }, { name: 'Item', accounts: [{ value: 1 }, { value: 2 }, { value: 3 }] }, { name: 'Item', accounts: [{ value: 1 }, { value: 2 }, { value: 3 }] }, { name: 'Item2', accounts: [{ value: 1 }, { value: 2 }, { value: 3 }] }, { name: 'Item2', accounts: [{ value: 1 }, { value: 2 }, { value: 3 }] }, { name: 'Item2', accounts: [{ value: 1 }, { value: 2 }, { value: 3 }] }],
    grouped = Object.values(accounts.reduce((obj, { name, accounts }) => {
        obj[name] = obj[name] || { name, accounts: [] };
        obj[name].accounts.push(...accounts);
        return obj;
    }, {}));

console.log(grouped);

.as-console-wrapper { max-height: 100% !important; top: 0; }

用reduce展平数组

1 个答案: