使用 Aspose.Cells for Node.js via C++ 管理数据透视表值字段

将字段添加到数据区域

将基本字段添加到数据（值）区域，是确定数据透视表如何汇总源数据的第一步。Aspose.Cells 提供了 PivotTable.AddFieldToArea(PivotFieldType, string) 重载，该重载接受常量 PivotFieldType.Data 和源列名称。字段添加到数据区域后，API 会通过 PivotTable.DataFields 集合按字段添加顺序将其公开。默认情况下，数值源列使用 Sum 汇总，而非数值列默认使用 Count 汇总。

const AsposeCells = require("aspose.cells");
const workbook = new AsposeCells.Workbook();
const worksheet = workbook.getWorksheets().get(0);
worksheet.setName("Data");
const headers = ["Category", "Item", "Year", "Amount"];
for (let j = 0; j < headers.length; j++) {
    worksheet.getCells().get(0, j).putValue(headers[j]);
}
const data = [
    ["Fruit",     "Apple",  2020, 100],
    ["Fruit",     "Apple",  2021, 150],
    ["Fruit",     "Banana", 2020,  80],
    ["Fruit",     "Banana", 2021,  90],
    ["Vegetable", "Carrot", 2020,  50],
    ["Vegetable", "Carrot", 2021,  60],
    ["Vegetable", "Daikon", 2020,  40],
    ["Vegetable", "Daikon", 2021,  45]
];
for (let i = 0; i < data.length; i++) {
    for (let j = 0; j < data[i].length; j++) {
        worksheet.getCells().get(i + 1, j).putValue(data[i][j]);
    }
}
const pivotIndex = worksheet.getPivotTables().add("A1:D9", "F3", "PivotTable1", true, false);
const pivotTable = worksheet.getPivotTables().get(pivotIndex);
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Row, "Category");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Row, "Item");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Column, "Year");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Data, "Amount");
pivotTable.calculateData();
workbook.save("output_drag.xlsx");

更改汇总函数

字段位于数据区域后，Aspose.Cells 会通过 PivotTable.DataFields 中的 PivotField 对象将其公开。每个 PivotField 都有一个可写的 Function 属性，其类型为 ConsolidationFunction，用于控制应用于该字段基础值的聚合方式。ConsolidationFunction 是一个枚举，包含 Sum、Count、Average、Max、Min、Product、StdDev、StdDevp、Var 和 Varp 成员。前六个成员可满足现实中的绝大多数使用场景，后四个成员则适用于方差分析等统计汇总。

更改 Function 只会影响汇总方式，不会修改源列以及数据透视表的行/列结构。要更改现有数据字段的汇总方式，请设置 pivotTable.DataFields[i].Function = ConsolidationFunction.<X>;，然后调用 pivotTable.CalculateData() 重新呈现数据透视表。

const AsposeCells = require("aspose.cells");
const workbook = new AsposeCells.Workbook();
const worksheet = workbook.getWorksheets().get(0);
worksheet.setName("Data");
const headers = ["Category", "Item", "Year", "Amount"];
for (let j = 0; j < headers.length; j++) {
    worksheet.getCells().get(0, j).putValue(headers[j]);
}
const data = [
    ["Fruit",     "Apple",  2020, 100],
    ["Fruit",     "Apple",  2021, 150],
    ["Fruit",     "Banana", 2020,  80],
    ["Fruit",     "Banana", 2021,  90],
    ["Vegetable", "Carrot", 2020,  50],
    ["Vegetable", "Carrot", 2021,  60],
    ["Vegetable", "Daikon", 2020,  40],
    ["Vegetable", "Daikon", 2021,  45]
];
for (let i = 0; i < data.length; i++) {
    for (let j = 0; j < data[i].length; j++) {
        worksheet.getCells().get(i + 1, j).putValue(data[i][j]);
    }
}
const pivotIndex = worksheet.getPivotTables().add("A1:D9", "F3", "PivotTable1", true, false);
const pivotTable = worksheet.getPivotTables().get(pivotIndex);
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Row, "Category");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Row, "Item");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Column, "Year");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Data, "Amount");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Data, "Amount");
pivotTable.getDataFields().get(1).setFunction(AsposeCells.ConsolidationFunction.Count);
pivotTable.calculateData();
workbook.save("output_function.xlsx");

将值字段放置到行轴或列轴

当数据透视表包含两个或更多数据字段时，Aspose.Cells 还会公开一个名为 PivotTable.ValuesField 的附加虚拟字段。该虚拟字段表示位于数据区域中的所有数据字段的汇总结果。你可以像基本数据透视字段一样将其拖放到行区域或列区域，从而并排布局多个度量值。

如果没有值字段，或仅有一个值字段，则 PivotTable.ValuesField 无法正常工作。

const AsposeCells = require("aspose.cells");
const workbook = new AsposeCells.Workbook();
const worksheet = workbook.getWorksheets().get(0);
worksheet.setName("Data");
const headers = ["Category", "Item", "Year", "Amount"];
for (let j = 0; j < headers.length; j++) {
    worksheet.getCells().get(0, j).putValue(headers[j]);
}
const data = [
    ["Fruit",     "Apple",  2020, 100],
    ["Fruit",     "Apple",  2021, 150],
    ["Fruit",     "Banana", 2020,  80],
    ["Fruit",     "Banana", 2021,  90],
    ["Vegetable", "Carrot", 2020,  50],
    ["Vegetable", "Carrot", 2021,  60],
    ["Vegetable", "Daikon", 2020,  40],
    ["Vegetable", "Daikon", 2021,  45]
];
for (let i = 0; i < data.length; i++) {
    for (let j = 0; j < data[i].length; j++) {
        worksheet.getCells().get(i + 1, j).putValue(data[i][j]);
    }
}
const pivotIndex = worksheet.getPivotTables().add("A1:D9", "F3", "PivotTable1", true, false);
const pivotTable = worksheet.getPivotTables().get(pivotIndex);
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Row, "Category");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Row, "Item");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Column, "Year");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Data, "Amount");
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Data, "Amount");
pivotTable.getDataFields().get(1).setFunction(AsposeCells.ConsolidationFunction.Count);
pivotTable.addFieldToArea(AsposeCells.PivotFieldType.Column, pivotTable.getValuesField());
pivotTable.calculateData();
workbook.save("output_plot.xlsx");