Tableau Data Types

Overview

Are you still confused about data types while working on the data in Tableau? You must read this article to get a good idea about data types in Tableau. In this article, we will go over different data types in Tableau and type conversions. If you are interested in analyzing in tableau, then you need to connect to the data source first. As we can see in the below image, we have connected to the Global Superstore data set and dragged Orders Sheet into the tableau. 

Just see there is a sheet displayed with column names and data types icons. In the below image there are column names as Category, City, Country, Customer Name, Market, Customer ID, etc. and above these names, if you observe there is a sheet name in grey color and above that, we can see some icons displayed like Abc for String values, Globe icon for geographical values, # for numbers, etc.  Apart from these icons, there are many icons to display the column data type information.

Also, if you see here on this page, we can reorder the columns data values in sorted order either ascending or descending as per the options in the Sort Fields drop-down as Data source order, A to Z ascending, Z to A descending, A to Z ascending per table, Z to A descending per table, modified, etc. 

Now, we will go over all the data types used in Tableau data values.

Icon	Data type
	Text (string) values
	Date values
	Date & Time values
	Numerical values
	Boolean values
	Geographic values (used with maps)

1. Text (String) Values: 

All the data values which are strings or if any character is enclosed in single quotes or double quotes then it will be treated as Text Data type.

For example, ‘0000’, “isProfitable”, Names, etc.

2. Date Values: Date value data type is the data which contains the dates like shipping date, Order date, Birth date. Date data type values will be in some specific date format as DD-MM-YY or DD-MM-YYYY.
3. Date and Time Values: There will be some data points in the date timestamp format.

Date Time Stamp data will be in the form of DD-MM-YYYY HH:MM: SS as 11-05-1994 00:00:00.

All the above data values will come under Date Data Type. Tableau recognizes all date formats but sometimes you need a string to be considered as a date then you can put ‘#’ before that string data values. E.g., “#3 Apr 2020”.

4. Numerical data type values: Tableau will consider Numeric data as Numerical data type.

This data type might be Integers, Decimal numbers, Floating Numbers, etc. 

 For example, Number of days, Sales, Profit, Discount, etc.

5. Boolean Data Type Values: Boolean data type is nothing but just a true or false value or it may be either 1 or 0. These are the Logical Values. E.g., True, False, 0, 1, etc.
6. Geographic Values: Geographic data types is one of the most important data types in Tableau where Tableau automatically assigns this data type if it finds the data value contains the location data like State, City, District, etc.

These values are more important to view your data points on maps with the help of latitude and longitude of different geographic locations.

How to change the data type of a particular field on the data source page in Tableau:

Sometimes Tableau interprets wrong data types as per the data values. For example, if data contains date values then sometimes tableau considers that values as an integer and displays the data type as numeric but not the date. 

So, in such a case we can change the data type of that field just by clicking on the icon on the data source page and select the correct data type from the list displayed.

One thing to remember that if you want to extract your data then we need to first check all the data types of data fields and then create the extract of the data otherwise your data will not be accurate and will cause some discrepancies. E.g., if you have floating data values in your data and you want that floating data should be decimal, then before creating extract you should change the datatype to decimal otherwise your extract data will contain inaccurate precisions.

How to change the data type of data values on data pane in a tableau worksheet?

As we learned in the above example that we can change the data type of any data values in Tableau.

Go to the Data pane in the Tableau worksheet and click on the icon just left of the dimensions or measures names. we will get the list of data types. Just select one which is preferred.

How to change the data type of data values which are present in the view:

Suppose if we have decided to change the data type of the data values in the tableau views or visuals created, then will follow below procedure to achieve the same:

1. Right click on the data field from dimensions or measures section in Tableau worksheet.
2. We will get below image. Just click on ‘Change Data Type’. Here we can see the same list as in earlier examples of changing data types.

Sometimes when Tableau automatically interprets the resultant data types and if they are not feasible with current data types then that data values are treated as some default values like NULL, BLANK, etc.

So, this is all about Tableau data types and a few conversion methods.

Hope you have understood the idea behind the data types in tableau and how one to convert them from one data type into another.