在JavaScript中联接数据的最佳方法是什么?是否有类似的库Pandas
中的Python
还是迭代方式?我有两个带有不同对象的数组。列表orders
包含有关订单的一般信息,列表ordersPayed
包含有关订单是否已付款+金额等的信息。
const orders = [
{
orderId: 1,
orderDate: '2018-01-01',
orderAmount: 100
},
{
orderId: 2,
orderDate: '2018-02-01',
orderAmount: 100
},
{
orderId: 3,
orderDate: '2018-03-01',
orderAmount: 100
},
{
orderId: 4,
orderDate: '2018-03-01',
orderAmount: 100
}];
const ordersPayed = [
{
orderId: 1,
payedAmount: 90,
debitorName: 'abc'
},
{
orderId: 3,
payedAmount: 80,
debitorName: 'abc'
},
{
orderId: 6,
payedAmount: 90,
debitorName: 'abc'
}];
let newOrderList = [];
for (i = 0; i < orders.length; i++) {
for (j = 0; j < ordersPayed.length; j++) {
if (orders[i].orderId == ordersPayed[j].orderId) {
newOrderList.push(orders[i].orderId);
newOrderList.push(orders[i].orderDate);
newOrderList.push(orders[i].orderAmount);
newOrderList.push(ordersPayed[j].payedAmount);
newOrderList.push(ordersPayed[j].debitorName);
}
else if (j == (ordersPayed.length-1)) {
newOrderList.push(orders[i].orderId);
newOrderList.push(orders[i].orderDate);
newOrderList.push(orders[i].orderAmount);
newOrderList.push('not_payed_yet');
newOrderList.push('not_known_yet');
}
}
}
console.log(newOrderList);
通过键orderId
完成匹配。最后,我想创建一个包含所有订单和相应信息的新列表,无论它们是否已经付款。
上面的代码是我要采用的方法,但是由于性能原因以及是否存在更多陷阱,我不知道这是否很好。所以我想到了一个匹配的库或类似的库。
不幸的是,这不能100%正确地工作。结果应如下所示:
[{
orderId: 1,
orderDate: '2018-01-01',
orderAmount: 100,
payedAmount: 90
},
{
orderId: 2,
orderDate: '2018-02-01',
orderAmount: 100,
payedAmount: 'not_payed_yet'
},
{
orderId: 3,
orderDate: '2018-03-01',
orderAmount: 100,
payedAmount: 80
},
{
orderId: 4,
orderDate: '2018-03-01',
orderAmount: 100,
payedAmount: 'not_payed_yet'
}]
有人提示吗?
答案 0 :(得分:5)
const newOrderList = orders.map((order, index) => {
let payedOrder = ordersPayed.find(o => o.orderId === order.orderId);
return Object.assign({}, order, payedOrder)
});
答案 1 :(得分:2)
您可以尝试以下解决方案:
// Returns an array with order objects, which contain all information
let newOrderList = orders.map((order, index) => {
let payedOrder = ordersPayed.find(o => o.orderId === order.orderId);
// Returns a new object to not manipulate the original one
return {
orderId: order.orderId,
orderDate: order.orderDate,
orderAmount: order.orderAmount,
payedAmount: payedOrder ? payedOrder.payedAmount : 'not_payed_yet',
debitorName: payedOrder ? payedOrder.debitorName: 'not_known_yet'
}
});
答案 2 :(得分:2)
使用lodash和ES6箭头表示法,解决方案可能会变得很短:
.as-console-wrapper {
max-height: 100% !important;
top: 0;
}
<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.10/lodash.min.js"></script>
REGEXP
答案 3 :(得分:1)
对于您的问题,我将minmanx-reduce: 148.5929143627707
default min + max: 3.376458476185718 # ouch .. seems we just use these
minmax1passOptimized: 15.975109436292087
minmax1pass: 20.29275910515082
与Array.reduce
一起使用:
Array.find
答案 4 :(得分:1)
您的代码中有一个小错误。 else if
不会按照您想要的方式工作,因为每当最后一次匹配失败时,您总是将not found
条目推入新数组。您可以尝试使用此调整后的代码版本:
const orders = [
{
orderId: 1,
orderDate: '2018-01-01',
orderAmount: 100
},
{
orderId: 2,
orderDate: '2018-02-01',
orderAmount: 100
},
{
orderId: 3,
orderDate: '2018-03-01',
orderAmount: 100
},
{
orderId: 4,
orderDate: '2018-03-01',
orderAmount: 100
}];
const ordersPayed = [
{
orderId: 1,
payedAmount: 90,
debitorName: 'abc'
},
{
orderId: 3,
payedAmount: 80,
debitorName: 'abc'
},
{
orderId: 6,
payedAmount: 90,
debitorName: 'abc'
}];
let newOrderList = [];
for (i = 0; i < orders.length; i++) {
let payed = false;
for (j = 0; j < ordersPayed.length; j++) {
if (orders[i].orderId == ordersPayed[j].orderId) {
newOrderList.push({ orderId: orders[i].orderId,
orderDate: orders[i].orderDate,
orderAmount: orders[i].orderAmount,
payedAmount: ordersPayed[j].payedAmount,
debitorName: ordersPayed[j].debitorName });
payed = true;
}
}
if (!payed) {
newOrderList.push({ orderId: orders[i].orderId,
orderDate: orders[i].orderDate,
orderAmount: orders[i].orderAmount,
payedAmount: 'not_payed_yet',
debitorName: 'not_known_yet' });
}
}
console.log(newOrderList);
但是请记住,只有在数据集之间具有1:1
关系时,这才起作用。这意味着如果您在ordersPayed
中可以有多个条目,而在orders
中可以有多个条目,那么结果也将为这些订单有多个条目。