Join & Group

Append and group fields from one layer to another using a matching field on both layers.

1. Explanation

This tool facilitates the combination of two datasets. By defining relationships, the tool aligns data from both layers. The resulting output is a new layer that contains the attributes from the Target Layer and a new column that summarizes a chosen attribute from the Join Layer.

GOAT uses the "Inner Join" operation to calculate a join which combines rows from a target and a join layer based on a related column between them. It only selects records that have matching values in both tables. This means that for every row in the target layer, there must be at least one row in the source layer to realize a successful match. Any rows that do not match will not be returned as a result.

2. Example use cases

• Summarizing population numbers from a table to a feature layer of zip-code areas (related column: zip-codes).
• Merge and aggregate the data from a household survey with the geometries of the census tract (related column: census tract).
• Joining the number of commuters from a table to a feature layer with the city boundaries (related column: city name).

3. How to use the tool?

1

Click on Toolbox .

2

Under the Data Management menu, click on Join & Group.

Select layers to join

3

Select your Target layer (the primary table or layer to which you want to add additional data).

4

Select your Join layer (the secondary table or dataset that contains the records and attributes to be inserted into the Target Layer).

Fields to match

5

Select the Target field of the target layer, which you like to use for matching the records of both layers.

6

Select the matching attribute of the Join Layer as the Join field.

Statistics

7

Select the Statistic Method to be used to join the attribute.

You can choose between several statistical operations. Some methods are only available for specific data types. The following list provides an overview of the available methods:

Method	Data Types	Description
Count	string,number	Counts the number of non-null values in the selected column
Sum	number	Calculates the sum of all the numbers in the selected column
Mean	number	Calculates the average (mean) value of all numeric values in the selected column
Median	number	Yields the middle value in the selected column's sorted list of numeric values
Min	number	Yields the minimum value of the selected column
Max	number	Yields the maximum value of the selected column

8

Select the Field Statistics for which you like to apply the statistical operation.

9

Click on Run.

Results

10

The resulting layer "Join" will be added to the project, as well as to the Datasets in your workspace. This layer consists of the information of the target layer and an additional column showing the results from the statistical operation. You can see the attributes by clicking on one of the features in the map.

Tip

Want to adjust the appearance of the result layer? Check out the attribute-based styling.