Tableau 简明教程

Tableau - Quick Guide

Tableau - Overview

Tableau 作为领先的数据可视化工具，拥有许多令人向往和独一无二的功能。其强大的数据发现和浏览应用程序让您可以在几秒钟内回答重要问题。您可以使用 Tableau 的拖放界面来可视化任何数据、浏览不同的视图，甚至轻松地组合多个数据库。它不需要任何复杂的脚本。任何了解业务问题的人都可以通过相关数据的可视化效果来解决问题。分析之后，只需发布到 Tableau Server 即可轻松与他人分享。

As a leading data visualization tool, Tableau has many desirable and unique features. Its powerful data discovery and exploration application allows you to answer important questions in seconds. You can use Tableau’s drag and drop interface to visualize any data, explore different views, and even combine multiple databases easily. It does not require any complex scripting. Anyone who understands the business problems can address it with a visualization of the relevant data. After analysis, sharing with others is as easy as publishing to Tableau Server.

Tableau Features

Tableau 为各种行业、部门和数据环境提供解决方案。以下是让 Tableau 能够处理各种场景的一些独一无二的功能。

Tableau provides solutions for all kinds of industries, departments, and data environments. Following are some unique features which enable Tableau to handle diverse scenarios.

Speed of Analysis − As it does not require high level of programming expertise, any user with access to data can start using it to derive value from the data.
Self-Reliant − Tableau does not need a complex software setup. The desktop version which is used by most users is easily installed and contains all the features needed to start and complete data analysis.
Visual Discovery − The user explores and analyzes the data by using visual tools like colors, trend lines, charts, and graphs. There is very little script to be written as nearly everything is done by drag and drop.
Blend Diverse Data Sets − Tableau allows you to blend different relational, semistructured and raw data sources in real time, without expensive up-front integration costs. The users don’t need to know the details of how data is stored.
Architecture Agnostic − Tableau works in all kinds of devices where data flows. Hence, the user need not worry about specific hardware or software requirements to use Tableau.
Real-Time Collaboration − Tableau can filter, sort, and discuss data on the fly and embed a live dashboard in portals like SharePoint site or Salesforce. You can save your view of data and allow colleagues to subscribe to your interactive dashboards so they see the very latest data just by refreshing their web browser.
Centralized Data − Tableau server provides a centralized location to manage all of the organization’s published data sources. You can delete, change permissions, add tags, and manage schedules in one convenient location. It’s easy to schedule extract refreshes and manage them in the data server. Administrators can centrally define a schedule for extracts on the server for both incremental and full refreshes.

Tableau - Environment Setup

在本章节中，您将了解 Tableau 的环境设置。

In this chapter, you will learn about the environment setup of Tableau.

Download Tableau Desktop

Tableau Desktop 的免费个人版可从 Tableau Desktop. 下载。您需要使用您的详细资料进行注册才能下载。

The Free Personal Edition of Tableau Desktop can be downloaded from Tableau Desktop. You need to register with your details to be able to download.

下载后，安装过程非常简单，您需要接受许可协议并提供安装目标文件夹。以下步骤和屏幕截图描述了整个安装过程。

After downloading, the installation is a very straightforward process in which you need to accept the license agreement and provide the target folder for installation. The following steps and screenshots describe the entire setup process.

Start the Installation Wizard

双击 TableauDesktop-64bit-9-2-2.exe 。它将显示一个允许安装程序运行的屏幕。单击“运行”。

Double-click the TableauDesktop-64bit-9-2-2.exe. It will present a screen to allow the installation program to run. Click “Run”.

Accept the License Agreement

阅读许可协议，如果您同意，请选择“我已阅读并接受该许可协议的条款”选项。然后，单击“安装”。

Read the license agreement and if you agree, choose the "I have read and accept the terms of this license agreement" option. Then, click "Install".

Start Trial

在安装完成后，屏幕将提示您选择立即开始还是稍后开始试用。您现在可以选择开始。此外，如果您已经购买了 Tableau，那么您可以输入许可证密钥。

On completion of the installation, the screen prompts you with the option to Start the trial now or later. You may choose to start it now. Also, if you have purchased Tableau then you may enter the License key.

Provide Your Details

提供姓名和组织详情。然后，单击“下一步”。

Provide your name and organization details. Then, click "Next".

Registration Complete

注册完成屏幕出现。单击“继续”。

The registration completion screen appears. Click "Continue".

Verify the Installation

您可以通过转到 Windows 开始菜单来验证安装。单击 Tableau 图标。将出现以下屏幕。

You can verify the installation by going to the Windows start menu. Click the Tableau icon. The following screen appears.

您现在可以了解 Tableau。

You are now ready to learn Tableau.

Tableau - Get Started

在本章中，你将学习 Tableau 中的一些基本操作以熟悉其界面。创建任何 Tableau 数据分析报表涉及三个基本步骤。

In this chapter, you will learn some basic operations in Tableau to get acquainted with its interface. There are three basic steps involved in creating any Tableau data analysis report.

这三个步骤分别是−

These three steps are −

Connect to a data source − It involves locating the data and using an appropriate type of connection to read the data.
Choose dimensions and measures − This involves selecting the required columns from the source data for analysis.
Apply visualization technique − This involves applying required visualization methods, such as a specific chart or graph type to the data being analyzed.

为方便起见，我们使用 Tableau 安装附带的示例数据集，名为 sample - superstore.xls。找到 Tableau 的安装文件夹并转至 My Tableau Repository 。在其下面，你在 Datasources\9.2\en_US-US 处将找到上述文件。

For convenience, let’s use the sample data set that comes with Tableau installation named sample – superstore.xls. Locate the installation folder of Tableau and go to My Tableau Repository. Under it, you will find the above file at Datasources\9.2\en_US-US.

Connect to a Data Source

在打开 Tableau 时，你将获得显示各种数据源的启动页。在标题 “Connect” 下，你可以选择文件、服务器或已保存的数据源。在“文件”下，选择 excel。然后导航到如上所述的文件 “Sample – Superstore.xls” 。excel 文件中有三个工作表，名为“订单”、“人员”和“退货”。选择 Orders 。

On opening Tableau, you will get the start page showing various data sources. Under the header “Connect”, you have options to choose a file or server or saved data source. Under Files, choose excel. Then navigate to the file “Sample – Superstore.xls” as mentioned above. The excel file has three sheets named Orders, People and Returns. Choose Orders.

Choose the Dimensions and Measures

接下来，根据维度和度量选择需要分析的数据。维度是描述性数据，而度量是数字数据。将两者放在一起时，它们有助于可视化维度数据的性能与度量数据的性能。选择 Category 和 Region 作为维度，选择 Sales 作为度量。将它们拖放至以下屏幕截图中所示的位置。结果显示了每个地区在每个类别中的总销售额。

Next, choose the data to be analyzed by deciding on the dimensions and measures. Dimensions are the descriptive data while measures are numeric data. When put together, they help visualize the performance of the dimensional data with respect to the data which are measures. Choose Category and Region as the dimensions and Sales as the measure. Drag and drop them as shown in the following screenshot. The result shows the total sales in each category for each region.

Apply Visualization Technique

在上一步中，您会看到这些数据仅以数字形式提供。您必须阅读和计算每一个值来判断性能。但是，您可以将它们作为图形或带有不同颜色的图表来查看，以更快速地做出判断。

In the previous step, you can see that the data is available only as numbers. You have to read and calculate each of the values to judge the performance. However, you can see them as graphs or charts with different colors to make a quicker judgment.

我们将 Marks 选项卡中的 sum（sales）列拖放到 Columns 区域中。现在，显示销售数字值的表格将自动变成条形图。

We drag and drop the sum (sales) column from the Marks tab to the Columns shelf. The table showing the numeric values of sales now turns into a bar chart automatically.

您可以应用一项技术，即向现有数据添加另一个维度。这会给现有条形图添加更多颜色，如下图所示。

You can apply a technique of adding another dimension to the existing data. This will add more colors to the existing bar chart as shown in the following screenshot.

Tableau - Navigation

在本章中，您将熟悉 Tableau 界面提供的各种导航功能。在运行 Tableau 桌面时，您将获得显示我们可以导航的所有命令的顶部菜单。让我们打开一个空白工作簿，并逐一了解每个菜单下的各种重要功能。

In this chapter, you will get acquainted with various navigational features available in Tableau interface. On running Tableau desktop, you get the menu at the top which shows all the commands we can navigate. Let’s open a blank workbook and go through the various important features under each menu.

Menu Commands

单击"获取开始"窗口时，您将获得包含所有可用菜单命令的主界面。它们代表 Tableau 中可用的整个功能集。以下图片中显示了菜单的各个部分。接下来，您还可以看到每个菜单的一些详细信息。

On closing the getting started window, you get the main interface with all the available Menu commands. They represent the entire set of features available in Tableau. Various sections of the menu are shown in the following diagram. Next, you can see some details of each menu.

File Menu

此菜单用于创建一个新的 Tableau 工作簿，并从本地系统和 Tableau 服务器中打开现有的工作簿。此菜单中的重要功能包括：

This menu is used to create a new Tableau workbook and open existing workbooks from both the local system and Tableau server. The important features in this menu are −

Workbook Locale sets the language to be used in the report.
Paste Sheets pastes a sheet into the current workbook, which is copied from another workbook.
Export Packaged Workbook option is used to create a packaged workbook, which will be shared with other users.

Data Menu

此菜单用于创建新的数据源以为分析和可视化获取数据。它还允许您替换或升级现有的数据源。

This menu is used to create new data source to fetch the data for analysis and visualization. It also allows you to replace or upgrade the existing data source.

此菜单中的重要功能包括：

The important features in this menu are as follows −

New Data Source allows to view all the types of connections available and choose from it.
Refresh All Extracts refreshes the data from the source.
Edit Relationships option defines the fields in more than one data source for linking.

Worksheet Menu

此菜单用于创建新的工作表，包含各种显示功能，如显示标题、标题等。

This menu is used to create a new worksheet along with various display features such as showing the title and captions, etc.

此菜单中的重要功能包括：

The important features in this menu are as follows −

Show Summary allows to view the summary of the data used in the worksheet such as, count, etc.
Tooltip shows the tooltip when hovering above various data fields.
Run Update option updates the worksheet data or filters used.

Dashboard Menu

此菜单用于创建新的仪表盘，包含各种显示功能，如显示标题、导出图像等。

This menu is used to create a new dashboard along with various display features, such as showing the title and exporting the image, etc.

此菜单中的重要功能包括：

The important features in this menu are as follows −

Format sets the layout in terms of colors and sections of the dashboard.
Actions link the dashboard sheets to external URLs or other sheets.
Export Image option exports an image of the Dashboard.

Story Menu

此菜单用于创建新的 story，该 story 具有许多具有关联数据 sheet 或仪表板。

This menu is used to create a new story which has many sheets or dashboards with related data.

此菜单中的重要功能包括：

The important features in this menu are as follows −

Format sets the layout in terms of colors and sections of the story.
Run Update updates the story with the latest data from the source.
Export Image option exports an image of the story.

Analysis Menu

此菜单用于分析 sheet 中显示的数据。Tableau 提供许多开箱即用的功能，例如计算百分比和执行预测等。

This menu is used for analyzing the data present in the sheet. Tableau provides many outof-the-box features, such as calculating the percentage and performing a forecast, etc.

此菜单中的重要功能包括：

The important features in this menu are as follows −

Forecast shows a forecast based on available data.
Trend Lines shows the trend line for a series of data.
Create Calculated Field option creates additional fields based on certain calculation on the existing fields.

Map Menu

此菜单用于在 Tableau 中构建地图视图。您可以为数据中的字段分配地理角色。

This menu is used for building map views in Tableau. You can assign geographic roles to fields in your data.

此菜单中的重要功能包括：

The important features in this menu are as follows −

Map Layers hides and shows map layers, such as street names, country borders, and adds data layers.
Geocoding creates new geographic roles and assigns them to the geographic fields in your data.

Format Menu

此菜单用于应用各种格式设置选项，以增强所创建仪表板的外观。它提供了边框、色彩、文本对齐等功能。

This menu is used for applying the various formatting options to enhance the look and feel of the dashboards created. It provides features such as borders, colors, alignment of text, etc.

此菜单中的重要功能包括：

The important features in this menu are as follows −

Borders applies borders to the fields displayed in the report.
Title & Caption assigns a title and caption to the reports.
Cell Size customizes the size of the cells displaying the data.
Workbook Theme applies a theme to the entire workbook.

Server Menu

服务器菜单用于在你拥有权限时登录 Tableau 服务器，并发布结果以供其他人使用。它还可以用来访问其他人发布的工作簿。

Server Menu is used to login to the Tableau server if you have access, and publish your results to be used by others. It is also used to access the workbooks published by others.

此菜单中的重要功能包括：

The important features in this menu are as follows −

Publish Workbook publishes the workbook in the server to be used by others.
Publish Data Source publishes the source data used in the workbook.
Create User Filters creates filters on the worksheet to be applied by various users while accessing the report.

Tableau - Design Flow

由于 Tableau 有助于分析大量数据（跨越不同的时间段、维度和度量），因此需要非常精心的规划才能创建良好的仪表板或故事。因此，了解设计良好仪表板的方法非常重要。与人类努力的任何其他领域一样，要创建良好工作表和仪表板，需要遵循许多最佳实践。

As Tableau helps in analyzing lots of data over diverse time periods, dimensions, and measures, it needs a very meticulous planning to create a good dashboard or story. Hence, it is important to know the approach to design a good dashboard. Like any other field of human endeavor, there are many best practices to be followed to create good worksheets and dashboards.

虽然 Tableau 项目的最终预期结果理想情况下是带有故事的仪表板，但在达成此目标之前有许多中间步骤需要完成。以下是设计步骤的流程图，应理想地遵循该流程图以创建有效的仪表板。

Though the final outcome expected from a Tableau project is ideally a dashboard with story, there are many intermediate steps which needs to be completed to reach this goal. Following is a flow diagram of design steps that should be ideally followed to create effective dashboards.

Connect to Data Source

Tableau 可连接到所有流行的数据源。它具有内置连接器，可在提供连接参数后负责建立连接。无论它是什么，是简单的文本文件、关系源、SQL 源还是云数据库，Tableau 几乎可连接到所有数据源。

Tableau connects to all popular data sources. It has inbuilt connectors which take care of establishing the connection, once the connection parameters are supplied. Be it simple text files, relational sources, SQL sources or cloud data bases, Tableau connects to nearly every data source.

Build Data Views

连接到数据源后，您会获得 Tableau 环境中提供的所有列和数据。您可以将它们归类为维度和度量，并创建所需的任何层次结构。使用它们，您可以构建视图，这些视图传统上称为报告。Tableau 提供简单的拖放功能来构建视图。

After connecting to a data source, you get all the column and data available in the Tableau environment. You classify them as dimensions and measures, and create any hierarchy required. Using these you build views, which are traditionally known as Reports. Tableau provides easy drag and drop feature to build views.

Enhance the Views

需要通过使用筛选器、聚合、轴标记、颜色和边框格式等方式进一步增强创建的视图。

The views created above needs to be enhanced further by the use of filters, aggregations, labeling of axes, formatting of colors and borders, etc.

Create Worksheets

创建不同的工作表以创建相同或不同数据上的不同视图。

Create different worksheets to create different views on the same or different data.

Create and Organize Dashboards

仪表板包含多个链接的工作表。因此，任何工作表中的操作都可以相应地更改仪表板中的结果。

Dashboards contain multiple worksheets which are linked. Hence, the action in any of the worksheet can change the result in the dashboard accordingly.

Create a Story

故事是一张包含一系列的工作表或仪表板的表格，它们共同协作以传达信息。您可以创建故事来展示事实如何联系起来，提供背景，演示决策与结果的关系，或者简单地提出一个令人信服的理由。

A story is a sheet that contains a sequence of worksheets or dashboards that work together to convey information. You can create stories to show how facts are connected, provide context, demonstrate how decisions relate to outcomes, or simply make a compelling case.

Tableau - File Types

Tableau 中的数据分析结果可以保存为各种格式，以便保存和分发。不同的格式被称为不同的文件类型，它们通过不同的扩展名来识别。它们的格式取决于它们如何生成以及用于什么目的。它们全都存储为 XML 文件，可以打开和编辑。

The result of data analysis in Tableau can be saved in various formats, to be saved and distributed. The various formats are referred as different file types and they are identified by different extensions. Their formats depend on how they are produced and for what purposes they are used. They are all stored as XML files, which can be opened and edited.

下表列出了每种文件类型的说明及其用法。

Following table lists the description of each file type and their usage.

File Type

File Extension

Purpose

Tableau Workbook

.twb

It contains information on each sheet and dashboard that is present in a workbook. It has the details of the fields, which are used in each view and the formula applied to the aggregation of the measures. It also has the formatting and styles applied. It contains the data source connection information and any metadata information created for that connection.

Tableau Packaged Workbook

.twbx

This file format contains the details of a workbook as well as the local data that is used in the analysis. Its purpose is to share with other Tableau desktop or Tableau reader users, assuming it does not need data from the server.

Tableau Data Source

.tds

The details of the connection used to create the tableau report are stored in this file. In the connection details, it stores the source type (excel/relational/sap, etc.) as well as the data types of the columns.

Tableau Packaged Data source

.tdsx

This file is similar to the .tds file with the addition of data along with the connection details.

Tableau Data Extract

.tde

This file contains the data used in a .twb file in a highly compressed columnar data format. This helps in storage optimization. It also saves the aggregated calculations that are applied in the analysis. This file should be refreshed to get the updated data from the source.

Tableau Bookmark

.tbm

These files contain a single worksheet that is shared easily to be pasted into other workbooks.

Tableau Preferences

.tps

This file stores the color preference used across all the workbooks. It is mainly used for consistent look and feel across the users.

Tableau - Data Types

作为数据分析工具，Tableau 将每条数据分类到四个类别之一，即字符串、数字、布尔值和日期时间。从源加载数据后，Tableau 会自动分配数据类型。相反，如果符合数据转换规则，您也可以更改一些数据类型。用户必须为计算字段指定数据类型。

As a data analysis tool, Tableau classifies every piece of data into one of the four categories namely - String, Number, Boolean and datetime. Once data is loaded from the source, Tableau automatically assigns the data types. Contrarily, you can also change some of the data types if it satisfies the data conversion rule. The user has to specify the data type for calculated fields.

下表列出了 Tableau 支持的数据类型的描述。

Following table lists the description of data types supported by Tableau.

Data Type

Description

Example

STRING

Any sequence of zero or more characters. They are enclosed within single quotes. The quote itself can be included in a string by writing it twice.

'Hello' 'Quoted' 'quote'

NUMBER

These are either integers or floating points. It is advised to round the floating point numbers while using them in calculations.

3 142.58

BOOLEAN

They are logical values.

TRUE FALSE

DATE & DATETIME

Tableau recognizes dates in almost all formats. But in case we need to force Tableau to recognize a string as date, then we put a # sign before the data.

"02/01/2015" "#3 March 1982"

Tableau - Show Me

作为一种高级数据可视化工具，Tableau 不需要编写任何自定义代码，就可以通过提供许多分析技术让数据分析变得非常容易。Show Me 就是此类功能之一。它可以用于将必需的视图应用于工作表中的现有数据。这些视图可以是饼图、散点图或折线图。

As an advanced data visualization tool, Tableau makes the data analysis very easy by providing many analysis techniques without writing any custom code. One such feature is Show Me. It can be used to apply a required view to the existing data in the worksheet. Those views can be a pie chart, scatter plot, or a line chart.

每当创建包含数据的工作表时，它都可用在右上角，如下面图片所示。一些视图选项将根据数据窗格中选择的性质而变灰。

Whenever a worksheet with data is created, it is available in the top right corner as shown in the following figure. Some of the view options will be greyed out depending on the nature of selection in the data pane.

Show Me with Two Fields

您可以使用 Show Me 中提供的各种图形和图表轻松地目视分析两个字段之间的关系。在本例中，我们选择两个字段并应用折线图。以下为步骤：

The relation between two fields can be visually analyzed easily by using various graphs and charts available in Show Me. In this case, we choose two fields and apply a line chart. Following are the steps −

Step 1 − Select the two fields (order date and profit) to be analyzed by holding the control key.
Step 2 − Click the Show Me bar and choose line chart.
Step 3 − Click the Mark Label button on the scrollbar.

以下图表展示使用上述步骤创建的折线图。

The following diagram shows the line chart created using the above steps.

Show Me with Multiple Fields

我们可以应用与上述类似的技术来分析多于 2 个字段。本例中的唯一差别在于活动形式中可用的视图较少。Tableau 会自动将不适合所选字段分析的视图变灰。

We can apply a similar technique as above to analyze more than 2 fields. The only difference in this case will be the availability of fewer views in active form. Tableau automatically greys out the views that are not appropriate for the analysis of the fields chosen.

此例中，按住 Control 键选择字段的产品名称、客户姓名、销售额和利润。正如您所观察到的那样，Show Me 中大多数视图都显示为灰色。从活动视图中选择散点视图。

In this case, choose the field’s product name, customer name, sales and profit by holding down the control key. As you can observe, most of the views in Show Me are greyed out. From the active views, choose Scatter View.

下图显示了创建的散点视图图表。

The following diagram shows the Scatter View chart created.

Tableau - Data Terminology

作为一款强大的数据可视化工具，Tableau 具有许多独特的术语和定义。在开始使用 Tableau 中的功能之前，您需要熟悉它们各自的含义。下面的术语列表比较全面，并且解释了最常用的术语。

As a powerful data visualization tool, Tableau has many unique terms and definitions. You need to get acquainted with their meaning before you start using the features in Tableau. The following list of terms is comprehensive and explains the terms most frequently used.

S.No	Terms & Meaning
1	Alias An alternative name that you can assign to a field or to a dimension member.
2	Bin A user-defined grouping of measures in the data source.
3	Bookmark A .tbm file in the Bookmarks folder in the Tableau repository that contains a single worksheet. Much like web browser bookmarks, .tbm files are a convenient way to quickly display different analyses.
4	Calculated Field A new field that you create by using a formula to modify the existing fields in your data source.
5	Crosstab A text table view. Use text tables to display the numbers associated with dimension members.
6	Dashboard A combination of several views arranged on a single page. Use dashboards to compare and monitor a variety of data simultaneously.
7	Data Pane A pane on the left side of the workbook that displays the fields of the data sources to which Tableau is connected. The fields are divided into dimensions and measures. The data pane also displays custom fields such as calculations, binned fields, and groups. You build views of your data by dragging fields from the data pane onto the various shelves that are a part of every worksheet.
8	Data Source Page A page where you can set up your data source. The data source page generally consists of four main areas − left pane, join area, preview area, and metadata area.
9	Dimension A field of categorical data. Dimensions typically hold discrete data such as hierarchies and members that cannot be aggregated. Examples of dimensions include dates, customer names, and customer segments.
10	Extract A saved subset of a data source that you can use to improve performance and analyze offline. You can create an extract by defining filters and limits that include the data you want in the extract.
11	Filters Shelf A shelf on the left of the workbook that you can use to exclude data from a view by filtering it using measures and dimensions.
12	Format Pane A pane that contains formatting settings that control the entire worksheet, as well as individual fields in the view. When open, the Format pane appears on the left side of the workbook.
13	Level Of Detail (LOD) Expression A syntax that supports aggregation at dimensionalities other than the view level. With the level of detail expressions, you can attach one or more dimensions to any aggregate expression.
14	Marks A part of the view that visually represents one or more rows in a data source. A mark can be, for example, a bar, line, or square. You can control the type, color, and size of marks.
15	Marks Card A card to the left of the view, where you can drag fields to control mark properties such as type, color, size, shape, label, tooltip, and detail.
16	Pages Shelf A shelf to the left of the view that you can use to split a view into a sequence of pages based on the members and values in a discrete or continuous field. Adding a field to the Pages shelf is like adding a field to the Rows shelf, except that a new page is created for each new row.
17	Rows Shelf A shelf at the top of the workbook that you can use to create the rows of a data table. The shelf accepts any number of dimensions and measures. When you place a dimension on the Rows shelf, Tableau creates headers for the members of that dimension. When you place a measure on the Rows shelf, Tableau creates quantitative axes for that measure.
18	Shelves Named areas to the left and top of the view. You build views by placing fields onto the shelves. Some shelves are available only when you select certain mark types. For example, the Shape shelf is available only when you select the Shape mark type.
19	Workbook A file with a .twb extension that contains one or more worksheets (and possibly also dashboards and stories).
20	Worksheet A sheet where you build views of your data by dragging fields onto shelves.

Tableau - Data Sources

Tableau 可以连接到广泛使用的所有流行数据源。Tableau 的本机连接器可以连接到以下类型的数据源。

Tableau can connect to all the popular data sources which are widely used. Tableau’s native connectors can connect to the following types of data sources.

File Systems such as CSV, Excel, etc.
Relational Systems such as Oracle, Sql Server, DB2, etc.
Cloud Systems such as Windows Azure, Google BigQuery, etc.
Other Sources using ODBC

下图显示了 Tableau 的本机数据连接器可提供的多数数据源。

The following picture shows most of the data sources available through Tableau’s native data connectors.

Connect Live

实时数据连接功能用于实时数据分析。在这种情况下，Tableau 会连接到实时数据源并不断读取数据。因此，分析结果是最新的，并且最新的更改会反映在结果中。但是，缺点是它会增加源系统负担，因为源系统必须不断向 Tableau 发送数据。

The Connect Live feature is used for real-time data analysis. In this case, Tableau connects to real-time data source and keeps reading the data. Thus, the result of the analysis is up to the second, and the latest changes are reflected in the result. However, on the downside, it burdens the source system as it has to keep sending the data to Tableau.

In-Memory

Tableau 还可以通过将数据缓存到内存中并不再连接到源来处理内存中的数据，同时分析数据。当然，缓存的数据量会有限制，取决于可用内存。

Tableau can also process data in-memory by caching them in memory and not being connected to the source anymore while analyzing the data. Of course, there will be a limit to the amount of data cached depending on the availability of memory.

Combine Data Sources

Tableau 可以同时连接到不同的数据源。例如，在单个工作簿中，您可以通过定义多个连接来连接到平面文件和关系源。这可用于数据混合，这是 Tableau 中一项非常独特的功能。

Tableau can connect to different data sources at the same time. For example, in a single workbook you can connect to a flat file and a relational source by defining multiple connections. This is used in data blending, which is a very unique feature in Tableau.

Tableau - Custom Data View

自定义数据视图用于扩展常规数据视图，并提供一些附加功能，以便视图可以针对相同的基础数据给出不同类型的图表。例如，您可以深入挖掘维度字段，这是预定义层次结构的一部分，以便获得以不同粒度获得的度量附加值。以下是 Tableau 提供的一些常用的重要自定义数据视图。

A custom data view is used to extend the normal data views with some additional features so that the view can give different types of charts for the same underlying data. For example, you can drill down a dimension field which is part of a pre-defined hierarchy so that additional values of the measures are obtained at a different granularity. Following are some of the frequently used and important custom data views Tableau offers.

Drill Down View

用于层次结构的维度字段，您通常需要了解聚合的下一个或上一个级别的分析结果。例如，当您了解到季度结果时，您就会对该季度内每个月的结果感兴趣，您可能还需要了解每周的结果。这是深入挖掘现有维度以获得更精细粒度级别的一个用例。

For dimension fields which are part of a hierarchy, you usually need to know the result of analysis for the next or previous level of aggregation. For example, when you know the result for a quarter, you get interested to know the results for each month in that quarter, and you may even need the result for each week. This is a case of drilling down the existing dimensions to get a finer level of granularity.

要在层次结构中深入挖掘和深入挖掘各个维度成员，请右键单击表格标题，然后从上下文菜单中选择深入挖掘。考虑使用“列”选区中的维度类别和“行”选区中的度量销售额创建的条形图。右键单击代表家具的条形，然后选择深入挖掘。

To drill down and drill up for individual dimension members in a hierarchy, right-click a table header and select Drill Down from the context menu. Consider a bar chart created with the dimension category in the columns shelf and the measure Sales in the Rows shelf. Right-click on the bar representing Furniture and select Drill Down.

深入挖掘操作的结果显示在以下屏幕截图中。

The result of the drill down action is shown in the following screenshot.

Swapping Dimensions

您可以通过交换维度的位置从现有视图创建新视图。这不会更改度量的值，但会更改度量的值的位置。考虑一个视图，用于分析每个产品细分和类别的每年的利润。您可以单击类别列末尾的竖线，然后将其拖动到细分列。此操作显示在以下屏幕截图中。

You can create a new view from an existing view by swapping the position of the dimensions. This does not change the values of the measures, but it does change the position of the measures. Consider a view for analyzing the Profit for each year for each segment and category of products. You can click on the vertical line at the end of category column and drag it to the segment column. This action is shown in the following screenshot.

交换这两个维度的结果显示在以下屏幕截图中。如您所见，只有每个类别和细分的度量利润的值的位置发生变化，而不是其值。

The result of the swapping of the two dimensions is shown in the following screenshot. As you can see, only the position of the values of the measure Profit changes for each category and segment, and not its value.

Tableau - Extracting Data

Tableau 中的数据提取从数据源中创建数据子集。这通过应用筛选器来提高性能很有用。它还有助于将 Tableau 的一些功能应用于数据，而这些功能可能在数据源中不可用，例如查找数据中的不同值。但是，数据提取功能最常用于创建要存储在本地驱动器中的提取，以便 Tableau 可脱机访问。

Data extraction in Tableau creates a subset of data from the data source. This is useful in increasing the performance by applying filters. It also helps in applying some features of Tableau to data which may not be available in the data source like finding the distinct values in the data. However, the data extract feature is most frequently used for creating an extract to be stored in the local drive for offline access by Tableau.

Creating an Extract

通过菜单“数据 → 提取数据”完成数据提取。它会创建许多选项，例如对要提取的行数应用限制以及是否要聚合维度数据。以下屏幕显示了“提取数据”选项。

Extraction of data is done by following the menu - Data → Extract Data. It creates many options such as applying limits to how many rows to be extracted and whether to aggregate data for dimensions. The following screen shows the Extract Data option.

Applying Extract Filters

要从数据源中提取数据子集，您可以创建筛选器，这些筛选器将仅返回相关行。让我们考虑 Sample Superstore 数据集并创建提取。在筛选器选项中，选择“从列表中选择”，然后选中要从源中提取数据所需复选框值。

To extract a subset of data from the data source, you can create filters which will return only the relevant rows. Let’s consider the Sample Superstore data set and create an extract. In the filter option, choose Select from list and tick mark the checkbox value for which you need to pull the data from the source.

Adding New Data to Extract

要为已创建的提取添加更多数据，可以选择选项“数据 → 提取 → 从文件中附加数据”。在此情况下，浏览包含数据的文件，然后单击“确定”以完成。当然，文件中的列数量和数据类型应与现有数据同步。

To add more data for an already created extract, you can choose the option Data → Extract → Append Data from File. In this case, browse the file containing the data and click OK to finish. Of course, the number and datatype of columns in the file should be in sync with the existing data.

Extract History

您可以验证数据提取历史记录，以确保了解提取发生了多少次以及在什么时间。

You can verify the history of data extracts to be sure about how many times the extract has happened and at what times.

为此，您可以使用菜单“数据 → 提取历史记录”。

For this, you can use the menu - Data → Extract History.

Tableau - Fields Operations

Tableau 有许多功能可用于操纵 Tableau 数据窗格中显示的字段。您可以重命名字段或合并两个字段以创建单个字段。此类操作有助于更好地组织维度和度量，以及针对两个或多个同名字段执行更好的数据分析。

Tableau has many features to manipulate the fields present in Tableau data pane. You can rename the fields or combine two fields to create one field. Such operations help in better organization of the dimensions and measures, as well as accommodate two or more fields with the same name for better data analysis.

以下是此类字段操作的一些重要示例。

Following are the important examples of such Field Operations.

Adding Fields to Worksheet

您可以通过右键单击并选择添加到工作表的选项向工作表添加任意字段。您还可以将字段拖放到工作表中存在的不同容器中，例如“列”容器、“行”容器、“筛选器”容器以及标记卡下的许多其他容器。下图显示了右键单击选项。

You can add any field to the worksheet by right-clicking and choosing the option Add to Sheet. You can also drag and drop the fields into different shelves present in the worksheet, like Columns shelf, Rows shelf, Filters shelf, and many other shelves under the Marks card. The following diagram shows the right-click option.

Combining Two Fields

您可以合并两个维度字段来创建一个字段。此合并字段有一个名称，它是由各个字段组合而成的。维度中的值通过将两个字符串组合成一个字符串（用逗号分隔）来组合成一个值。但是，可以通过使用重命名字段操作来更改此默认名称。下图显示了合并两个字段的步骤。

You can combine two dimension fields to create one field. This combined field has a name which is a combination of the individual fields. The values in the dimension get combined to a single value by joining the two strings into one string separated by a comma. However, this default name can be changed by using the rename field operation. The following diagram shows the step to combine two fields.

Searching Fields

您可以使用搜索框选项搜索字段的名称。编写字段名称的前三个或更多个字母会显示仅显示名称中包含这些字母的字段的结果。

You can search for names of fields by using the search box option. Writing first three or more letters of the field name brings out the result showing only the fields whose name contains these letters.

Reordering Fields

您可以通过简单地向上或向下拖动字段来更改字段的位置。在以下示例中，我们将字段客户姓名拖到州和城市之间的位置。通常这样做是为了将经常用于分析的相似字段组合在一起。

You can change the position of fields by simply dragging them up and down. In the following example, we drag the field customer name to the place between state and city. This is usually done to bring similar fields together which are frequently used for analysis.

Tableau - Editing Metadata

连接到数据源后，Tableau 会捕获源的元数据详细信息，如列及其数据类型。这用于在视图中创建维度、度量和计算字段。可以浏览元数据并更改其中一些属性以满足某些特定要求。

After connecting to the data source, Tableau captures the metadata details of the source like the columns and their data types. This is used to create the dimensions, measures, and calculated fields used in views. You can browse the metadata and change some of its properties for some specific requirements.

Checking the Metadata

连接到数据源后，Tableau 会显示源中存在的所有可能表和列。考虑源“Sample Coffee shop”以检查元数据。单击数据菜单，然后选择连接到数据源。浏览名为“Sample - Coffee shop”的 MS access 文件。将名为 Product 的表拖到数据画布。在选择文件时，你将获得以下屏幕，其中显示列名称及其数据类型。字符串数据类型显示为 Abc ，而数字数据类型显示为 #。

After connecting to a data source, Tableau presents all possible tables and columns present in the source. Consider the source ‘Sample Coffee shop’ for checking the metadata. Click the Data menu and choose to connect to a data source. Browse for the MS access file named ‘Sample - Coffee shop’. Drag the table named Product to the data canvas. On choosing the file, you get the following screen which shows the column names, their data types. The string data types are shown as Abc and Numeric data types are shown as #.

Changing the Data Type

如果需要，可以更改某些字段的数据类型。根据源数据，有时 Tableau 可能无法从源识别数据类型。在这种情况，我们可以手动编辑数据类型。以下屏幕截图显示了该选项。

You can change the datatype of some of the fields if required. Depending on the nature of source data, sometimes Tableau may fail to recognize the data type from the source. In such scenarios, we can manually edit the data type. The following screenshot shows the option.

Renaming and Hiding

可以通过重命名选项更改列名称。还可以隐藏列，使其不会出现在创建的数据视图中。这些选项可通过单击元数据网格中的数据类型图标获得，如下面的屏幕截图所示。

The column names can be changed by using the renaming option. You can also hide a column so that it does not appear in the data view that you create. These options are available by clicking on the data type icon in the metadata grid as shown in the following screenshot.

Column Alias

可以为数据源的每一列指定别名，这有助于更好地理解列的性质。可以选择上述步骤中的别名选项，将会出现以下屏幕，用于创建或编辑别名。

Each column of the data source can be assigned an alias which helps better understand the nature of the column. You can choose the aliases option from the above step and the following screen comes up which is used to create or edit aliases.

Tableau - Data Joining

数据连接是任何数据分析中非常常见的需求。您可能需要连接来自多个来源的数据或连接单个来源中来自不同表的数据。Tableau 提供了使用数据菜单下编辑数据源中提供的“数据”窗格连接表的功能。

Data joining is a very common requirement in any data analysis. You may need to join data from multiple sources or join data from different tables in a single source. Tableau provides the feature to join the table by using the data pane available under Edit Data Source in the Data menu.

Creating a Join

考虑数据源“示例超级商店”，在“订单”和“退货”表之间创建连接。为此，请转到数据菜单并选择编辑数据源选项。接下来，将两个表（订单和退货）拖到“数据”窗格。Tableau 将根据字段名称和数据类型自动创建连接，此连接以后可以更改。

Consider the data source ‘Sample superstore’ to create a join between Orders and Returns table. For this, go to the Data menu and choose the option Edit Data Source. Next, drag the two tables, Orders and Returns to the data pane. Depending on the field name and datatype, Tableau will automatically create a join which can be changed later.

下图显示了使用字段订单 ID 创建订单和退货之间的内部连接。

The following screenshot shows the creation of an inner join between Orders and Returns using the Field Order ID.

Editing a Join Type

表自动创建的连接类型可以手动更改。为此，请单击显示连接的两个圆圈的中间。下方出现一个弹出窗口，显示四种可用连接类型。此外，Tableau 根据数据源中存在的数据自动灰显某些类型的连接，认为这些连接无关。

The type of join which the table creates automatically can be changed manually. For this, click the middle of the two circles showing the join. A popup window appears below which shows the four types of joins available. Also Tableau automatically greys out some types of joins, which it finds irrelevant on the basis of data present in the data source.

在下图中，您可以看到内部连接和左外部连接作为可用连接。

In the following screenshot, you can see the inner and left outer join as the available joins.

Editing Join Fields

您还可以通过单击连接弹出窗口中可用的数据源选项来更改形成连接条件的字段。在选择该字段时，您还可以使用搜索文本框搜索正在寻找的字段。

You can also change the fields forming the join condition by clicking the Data Source option available in the join popup window. While selecting the field, you can also search for the field you are looking for using a search text box.

Tableau - Data Blending

数据混合是 Tableau 中一个非常强大的功能。当多个数据源中存在相关数据时，您希望将它们分析到单个视图中，这时就使用数据混合。例如，考虑了在关系数据库中的销售数据和 Excel 电子表格中的销售目标数据。现在，为了将实际销售额与目标销售额进行比较，您可以基于公共维度混合数据以获取 Sales Target 度量。数据混合中的两个源被称为主要数据源和辅助数据源。在主要数据源和辅助数据源之间创建左连接，其中包括主要数据源的所有数据行以及来自辅助数据源的匹配数据行。

Data Blending is a very powerful feature in Tableau. It is used when there is related data in multiple data sources, which you want to analyze together in a single view. As an example, consider the Sales data is present in a relational database and Sales Target data in an Excel spreadsheet. Now, to compare actual sales to target sales, you can blend the data based on common dimensions to get access to the Sales Target measure. The two sources involved in data blending are referred as primary and secondary data sources. A left join is created between the primary data source and the secondary data source with all the data rows from primary and matching data rows from secondary data source.

Preparing Data for Blending

Tableau 有两个内置数据源 Sample-superstore 和 Sample coffee chain.mdb ，它们将用于说明数据混合。

Tableau has two inbuilt data sources named Sample-superstore and Sample coffee chain.mdb which will be used to illustrate data blending.

首先，将示例咖啡连锁店加载到 Tableau 并查看其元数据。转到菜单 - Data → New Data Source 并浏览示例咖啡连锁店文件，它是一个 MS Access 数据库文件。下面的屏幕截图显示了文件中提供的不同表和连接。

First load the sample coffee chain to Tableau and look at its metadata. Go to the menu - Data → New Data Source and browse for the sample coffee chain file, which is a MS Access database file. The following screenshot shows the different tables and joins available in the file.

Adding Secondary Data Source

接下来，通过再次按照步骤 - Data → New Data Source 并选择此数据源来添加名为 Sample-superstore 的辅助数据源。这两个数据源现在会像下面的屏幕截图中所示那样显示在 Data 窗口中。

Next, add the secondary data source named Sample-superstore by again following the steps - Data → New Data Source and choosing this data source. Both the data sources now appear on the Data window as shown in the following screenshot.

Blending the Data

现在，您可以基于公共维度集成来自以上两个源的数据。请注意，在名为 State 的维度旁边会出现一个小的链条图像。这表示两个数据源之间的公共维度。将主数据源中的 State 字段拖动到 rows 货架，将次数据源中的 Profit Ratio 字段拖动到 Columns 货架。然后，从 Show Me 中选择子弹图选项以获取下面的屏幕截图中所示的子弹图。该图表显示了连锁超市和咖啡店中各个州的利润率如何变化。

Now you can integrate the data from both the above sources based on a common dimension. Note that a small chain image appears next to the dimension named State. This indicates the common dimension between the two data sources. Drag the State field from the primary data source to the rows shelf and the field Profit Ratio from the secondary data source to the Columns shelf. Then, select the bullet chart option from Show Me to get the bullet chart shown in the following screenshot. The chart shows how the profit ratio varies for each state in both the superstore and coffee chain shops.

Tableau - Add Worksheets

Tableau 屏幕中的工作表是创建数据分析视图的区域。当您建立与数据源的连接时，Tableau 默认提供三个空白工作表。您可以继续添加多个工作表，在一个屏幕中一个接一个地查看不同的数据视图。

Worksheet in the Tableau screen is the area where you create the views for data analysis. By default, Tableau provides three blank worksheets when you have established a connection to data source. You can go on adding multiple worksheets to look at different data views in the same screen, one after another.

Adding a Worksheet

您可以通过两种方式添加工作表。右键单击当前工作表的名称，然后从弹出菜单中选择新建工作表选项。您还可以单击最后一张工作表名称右侧的小图标来添加工作表。

You can add a worksheet in two ways. Right-click on the name of the current worksheet and choose the option New Worksheet from the pop-up menu. You can also click on the small icon to the right of the last sheet name to add a worksheet.

Quick Preview of a Worksheet

停留在一个工作表中，可以通过将鼠标悬停在另一个工作表的名称上来快速预览另一个工作表。

Staying in one worksheet, you can have a quick preview of another worksheet by hovering the mouse on the name of the other worksheet.

Tableau - Rename Worksheet

您可以通过重命名工作表来为现有工作表指定适当的名称。这有助于将工作表的内容与其名称联系起来。例如，如果我们想知道哪个工作表具有了解分段利润的视图，那么我们可以通过适当的工作表名称来识别它。

You can give appropriate names to the existing worksheets by renaming a worksheet. This helps in relating the content of the worksheet with its name. For example, if we want to know which sheet has the view to know the segment wise profit then with a proper name of the sheet we can identify it.

Renaming the Worksheet

要重命名工作表，请右键单击工作表名称，然后选择重命名工作表选项。

To rename a worksheet, right-click the sheet name and choose the option Rename Sheet.

下图显示了具有新名称的工作表。

The following diagram shows the worksheet with the new name.

Tableau - Save & Delete Worksheet

现有工作表可以同时保存和删除。这有助于整理 Tableau 桌面环境中的内容。虽然您可以通过单击主菜单下的保存按钮保存工作表，但您还可以使用以下步骤删除工作表。

An existing worksheet can be both saved and deleted. This helps in organizing the contents in the Tableau desktop environment. While you can save a worksheet by clicking the save button under the main menu, you can delete a worksheet using the following steps.

Deleting the Worksheet

要删除工作表，右键单击工作表的名称并选择选项“删除工作表”。

To delete a worksheet, right-click on name of the worksheet and choose the option ‘Delete Sheet’.

以下屏幕截图显示工作表已被删除。

The following screenshot shows the worksheet has been deleted.

Tableau - Reorder Worksheet

有时候，您需要更改现有工作表的位置，以便更好地研究它们。可以通过将表格名称从其现有位置拖到新位置来简单地完成此操作。

Sometimes you need to change the position of the existing worksheet to study them in a better way. This can be done in a simple way by dragging the sheet name from its existing position to the new position.

Reordering the Worksheet

要重新排列工作表，请单击并按住工作表名称，然后将其移动到所需位置。考虑以下屏幕截图中显示的三个工作表。

To reorder a worksheet, click and hold the worksheet name and move it to the desired position. Consider the three worksheets as shown in the following screenshot.

以下屏幕截图显示了在将第三个工作表从左侧拖到新位置时，在新位置上会出现一条竖直的深色线。

The following screenshot shows that a vertical dark line appears in the new position on dragging the third worksheet from left to the new position.

Tableau - Paged Workbook

分页工作簿用于为维度或度量的不同值在不同页面中保存数据的视图。一个常见的示例是查看每种产品类型在特定销售区域中相对于其他产品类型的表现情况。由于每种产品类型的不同值都存储在一个单独的页面中，我们可以一次查看它们或将它们视为一个值范围。

A paged workbook is used to save the view of the data in different pages for different values of the dimension or measure. A common example is to see how each type of products have performed against each other in a specific sales region. As each of the values of product type is stored as a separate page, we can view them one at a time or see it as a range of values.

Creating Paged Workbook

分页工作簿包含将字段放置在页面架上的工作表。考虑研究产品不同子类别在不同地区的利润的示例。以下为步骤。

The paged workbook contains worksheets which have fields put in the page shelf. Consider an example of studying the profit of various sub-category of products in different regions. Following are the steps.

Step 1 − 创建具有两个维度和一个度量的条形图。在此情况下，将度量“利润”拖动到列架，将维度“子类别”和“地区”拖动到行架，如下图所示。

Step 1 − Create a bar chart with two dimensions and one measure. In this case, drag the Measure Profit to the columns shelf and the dimensions sub-category, and Region to the rows shelf as shown in the following screenshot.

Step 2 - 再次将子类别字段拖到页面栏。你将看到自动添加了一个页面控件，就在页面栏的下方。此页面控件提供以下功能，以导航视图中的页面：

Step 2 − Drag the Sub-Category field again to the page shelf. You will see that a page control is automatically added, just below the Pages shelf. This page control provides the following features to navigate through the pages in a view −

Jump to a specific page
Manually advance through the pages
Automatically advance through pages

在此示例中，我们将了解如何跳转到特定页面以及如何获取页面的自动显示。要转到特定页面，请单击页面控件上的下拉列表，然后选择配件。出现以下屏幕截图所示的图表。

In this case, we will see how to jump to a specific page and how to get the automatic display of pages. To go to a specific page, click on the drop-down on the page control and select Accessories. The chart seen in the following screenshot appears.

Step 3 - 对于页面的自动显示，保持显示历史记录复选框被选中，然后单击播放按钮。然后可以看到子类别的不同页面自动播放。当前子类别值显示为暗色，而前值则以浅色显示。以下屏幕截图对此进行了说明。

Step 3 − For automatic display of pages, keep the show history checkbox ticked and click the play button. You can then see an automatic play of different pages of sub categories. While the current Sub-Category value is shown with a dark color, the previous values are shaded with light color. The following screenshot illustrates this.

Tableau - Operators

运算符是一个符号，它告诉编译器执行特定的数学或逻辑操作。Tableau 具有许多运算符，用于创建计算字段和公式。

An operator is a symbol that tells the compiler to perform specific mathematical or logical manipulations. Tableau has a number of operators used to create calculated fields and formulas.

以下是可用运算符的详细信息以及运算的顺序（优先级）。

Following are the details of the operators that are available and the order (precedence) of operations.

Types of Operator

General Operators
Arithmetic Operators
Relational Operators
Logical Operators

General Operators

下表显示了 Tableau 支持的通用运算符。这些运算符作用于数字、字符和日期数据类型。

Following table shows the general operators supported by Tableau. These operators act on numeric, character, and date data types.

Operator

Description

Example

+(addition)

Adds two numbers. Concatenates two strings. Adds days to dates.

7 + 3 Profit + Sales 'abc' + 'def' = 'abcdef' April 15, 2004 + 15 = April 30, 2004

–(subtraction)

Subtracts two numbers. Subtracts days from dates.

-(7+3) = -10 April 16, 2004 - 15 = April 1, 2004

Arithmetic Operators

下表显示了 Tableau 支持的算术运算符。这些运算符仅对数字数据类型起作用。

Following table shows the arithmetic operators supported by Tableau. These operators act only on numeric data types.

Operator

Description

Example

*(Multiplication)

Numeric multiplication

23*2 = 46

/(Division)

Numeric division

45/2 = 22.5

%(modulo)

Reminder of numeric division

13 % 2 = 1

^(power)

Raised to the power

2^3 = 8

Comparison Operators

下表列出了 Tableau 支持的比较运算符。这些运算符用于表达式中。每个运算符将比较两个数字、日期或字符串，并返回布尔值（真或假）。然而，布尔值本身无法使用这些运算符比较。

Following table lists the comparison operators supported by Tableau. These operators are used in expressions. Each operator compares two numbers, dates, or strings and returns a Boolean (TRUE or FALSE). Booleans themselves, however, cannot be compared using these operators.

Operator

Description

Example

= = or = (Equal to)

Compares two numbers or two strings or two dates to be equal. Returns the Boolean value TRUE if they are, else returns false.

‘Hello’ = ‘Hello’ 5 = 15/ 3

!= or <> (Not equal to)

Compares two numbers or two strings or two dates to be unequal. Returns the Boolean value TRUE if they are, else returns false.

‘Good’ <> ‘Bad’ 18 != 37 / 2

> (Greater than)

Compares two numbers or two strings or two dates where the first argument is greater than second. Returns the boolean value TRUE if it is the case, else returns false.

[Profit] > 20000 [Category] > ‘Q’ [Ship date] > April 1, 2004

< (Less than)

Compares two numbers or two strings or two dates where the first argument is smaller than second. Returns the boolean value TRUE if it is the case, else returns false.

[Profit] < 20000 [Category] < ‘Q’ [Ship date] < April 1, 2004

Logical Operators

下表显示了 Tableau 支持的逻辑运算符。这些运算符用于表达式中，该表达式的结果为布尔值，输出为真或假。

Following table shows the logical operators supported by Tableau. These operators are used in expressions whose result is a Boolean giving the output as TRUE or FALSE.

Operator

Description

Example

AND

If the expressions or Boolean values present on both sides of AND operator is evaluated to be TRUE, then the result is TRUE. Else the result is FALSE.

[Ship Date] > April 1, 2012 AND [Profit] > 10000

If any one or both of the expressions or Boolean values present on both sides of AND operator is evaluated to be TRUE, then the result is TRUE. Else the result is FALSE.

[Ship Date] > April 1, 2012 OR [Profit] > 10000

NOT

This operator negates the Boolean value of the expression present after it.

NOT [Ship Date] > April 1, 2012

Operator Precedence

下表描述了运算符的评估顺序。最上面一行优先级最高。处于同一行的运算符具有相同的优先级。如果两个运算符具有相同的优先级，则从左到右在公式中对其进行评估。还可以使用括号。圆括号内侧内容在圆括号外侧内容前评估。

The following table describes the order in which operators are evaluated. The top row has the highest precedence. Operators on the same row have the same precedence. If two operators have the same precedence, they are evaluated from left to right in the formula. Also parentheses can be used. The inner parentheses are evaluated before the outer parentheses.

Precedence	Operator
1	–(negate)
2	^(power)
3	*, /, %
4	+, –
5	==, >, <, >=, ⇐, !=
6	NOT
7	AND
8	OR

Tableau - Functions

任何数据分析都涉及大量计算。在 Tableau 中，计算编辑器用于将计算应用于正在分析的字段。Tableau 具有许多内置函数，有助于创建复杂计算的表达式。

Any data analysis involves a lot of calculations. In Tableau, the calculation editor is used to apply calculations to the fields being analyzed. Tableau has a number of inbuilt functions which help in creating expressions for complex calculations.

以下是不同函数类别的说明。

Following are the description of different categories of functions.

Number Functions
String Functions
Date Functions
Logical Functions
Aggregate Functions

Number Functions

这些是用于数字计算的函数。它们仅将数字作为输入。以下是一些重要的数字函数示例。

These are the functions used for numeric calculations. They only take numbers as inputs. Following are some examples of important number functions.

Function

Description

Example

CEILING (number)

Rounds a number to the nearest integer of equal or greater value.

CEILING(2.145) = 3

POWER (number, power)

Raises the number to the specified power.

POWER(5,3) = 125

ROUND (number, [decimals])

Rounds the numbers to a specified number of digits.

ROUND(3.14152,2) = 3.14

String Functions

字符串函数用于字符串处理。以下是带有示例的一些重要的字符串函数

String Functions are used for string manipulation. Following are some important string functions with examples

Function

Description

Example

LEN (string)

Returns the length of the string.

LEN("Tableau") = 7

LTRIM (string)

Returns the string with any leading spaces removed.

LTRIM(" Tableau ") = "Tableau"

REPLACE (string, substring, replacement)

Searches the string for substring and replaces it with a replacement. If the substring is not found, the string is not changed.

REPLACE("GreenBlueGreen", "Blue", "Red") = "GreenRedGreen"

UPPER (string)

Returns string, with all characters uppercase.

UPPER("Tableau") = "TABLEAU"

Date Functions

Tableau 具有各种日期函数来执行涉及日期的计算。所有日期函数都使用 date_part ，这是一个字符串，指定日期的一部分，例如月份、日期或年份。下表列出了一些重要的日期函数示例。

Tableau has a variety of date functions to carry out calculations involving dates. All the date functions use the date_part which is a string indicating the part of the date such as - month, day, or year. Following table lists some examples of important date functions.

Function

Description

Example

DATEADD (date_part, increment, date)

Returns an increment added to the date. The type of increment is specified in date_part.

DATEADD ('month', 3, 2004-04-15) = 2004-0715 12:00:00 AM

DATENAME (date_part, date, [start_of_week])

Returns date_part of date as a string. The start_of_week parameter is optional.

DATENAME('month', 200404-15) = "April"

DAY (date)

Returns the day of the given date as an integer.

DAY(2004-04-12) = 12

NOW( )

Returns the current date and time.

NOW( ) = 2004-04-15 1:08:21 PM

Logical Functions

这些函数计算某些单一值或表达式的结果，并生成布尔输出。

These functions evaluate some single value or the result of an expression and produce a boolean output.

Function

Description

Example

IFNULL (expression1, expression2)

The IFNULL function returns the first expression if the result is not null, and returns the second expression if it is null.

IFNULL([Sales], 0) = [Sales]

ISDATE (string)

The ISDATE function returns TRUE if the string argument can be converted to a date, and FALSE if it cannot.

ISDATE("11/05/98") = TRUE ISDATE("14/05/98") = FALSE

MIN(expression)

The MIN function returns the minimum of an expression across all records or the minimum of two expressions for each record.

Aggregate Functions

Function

Description

Example

AVG(expression)

Returns the average of all the values in the expression. AVG can be used with numeric fields only. Null values are ignored.

COUNT (expression)

Returns the number of items in a group. Null values are not counted.

MEDIAN (expression)

Returns the median of an expression across all records. Median can only be used with numeric fields. Null values are ignored.

STDEV (expression)

Returns the statistical standard deviation of all values in the given expression based on a sample of the population.

Tableau - Numeric Calculations

Tableau 中的数字计算使用公式编辑器中提供的广泛内置函数来完成。

Numeric calculations in Tableau are done using a wide range of inbuilt functions available in the formula editor.

在本章中，我们将看到如何将计算应用到字段。计算可以像减去两个字段的值或对单个字段应用聚合函数一样简单。

In this chapter, we will see how to apply calculations to the fields. The calculations can be as simple as subtracting the values of two fields or applying an aggregate function to a single field.

以下是在 Tableau 中创建计算字段并使用数字函数的步骤。

Following are the steps to create a calculation field and use numeric functions in it.

Create Calculated Field

连接到 Sample-superstore 时，转至“分析”菜单，然后单击“创建计算字段”，如下图所示。

While connected to Sample-superstore, go to the Analysis menu and click ‘Create Calculated Field’, as shown in the following screenshot.

Calculation Editor

上述步骤会打开一个计算编辑器，该编辑器会列出 Tableau 中可用的所有函数。您可以更改下拉值，只查看与数字相关的函数。

The above step opens a calculation editor which lists all the functions that is available in Tableau. You can change the dropdown value and see only the functions related to numbers.

Create a Formula

为了研究不同产品运输方式的利润与折扣之间的差异，创建一个公式，减去利润的折扣，如下图所示。此外，将此字段命名为 profit_n_discount 。

To study the difference between profit and discount for different shipping mode of the products, create a formula subtracting the discount from the profit as shown in the following screenshot. Also, name this field as profit_n_discount.

Using the Calculated Field

上述计算出的字段可通过将该字段拖动至"行"架来应用到视图中，如下图所示。它制作出的条形图显示了不同运输方式的利润和折扣之间的差值。

The above calculated field can be used in the view by dragging it to the Rows shelf as shown in the following screenshot. It produces a bar chart showing the difference between profit and discount for different shipping modes.

Applying Aggregate Calculations

同如上所示，您可以使用聚合函数来创建计算字段。此处，为不同的运输方式创建 AVG(销售) 值。如以下屏幕截图中所示，在计算编辑器中编写公式。

In a similar manner as above, you can create a calculated field using aggregate function. Here, create AVG(sales) values for different ship mode. Write the formula in the calculation editor as shown in the following screenshot.

单击"确定"后并将 Avg_Sales 字段拖至"行"架，您将得到以下视图。

On clicking OK and dragging the Avg_Sales field to the Rows shelf, you will get the following view.

Tableau - String Calculations

在本章中，你将了解 Tableau 中涉及字符串的计算。Tableau 具有许多内置的字符串函数，可用于执行字符串操作，例如 - 比较、级联、替换字符串中的几个字符等。以下是创建计算字段并在其中使用字符串函数的步骤。

In this chapter, you will learn about calculations in Tableau involving Strings. Tableau has many inbuilt string functions, which can be used to do string manipulations such as - comparing, concatenating, replacing few characters from a string, etc. Following are the steps to create a calculation field and use string functions in it.