ARCHIVED: In ArcGIS, how do I join or relate attribute tables?

Most database design guidelines recommend organizing your database into multiple tables, each focused on a specific topic, rather than having one large table contain all the necessary fields. When you need information that isn't in your current table, you can link it to another one. In ArcMap, you do this by either joining or relating two tables together.

Joining tables

Typically, you will join a table of data to a dataset by a field value found in both tables. The fields do not have to share the same name, but they must have the same data types (e.g., you must join a floating number field to another floating number field). To join two datasets:

1. In ArcMap,right-click the layer to which you want to join attributes, point to Joins and Relates, and click Join.
2. To join two spatial datasets, click the first drop-down arrow and click Join data from another layer based on spatial location. To join a table of non-spatial data to the existing layer, click Join attributes from a table.
3. In this example, we will join two spatial datasets. To choose the layer to join to the existing layer, click the drop-down arrow, and select the name of the layer with attributes you wish to join. If the layer is not currently part of the map, click Browse to search for it on your computer.
4. You may choose the option to join the attributes of the features that fall inside the polygon or the option to join the attributes of the features that intersect it.
5. Enter the location and name of the output shapefile or feature class.
6. Click OK. A new layer will be added to the map.

To join INFO tables in a coverage, see the ESRI support article Join Info Tables.

Relating tables

Unlike joining tables, relating two tables simply defines a relationship between them. The associated data aren't appended to the layer's attribute table as they are with a join. Instead, you can access the related data when you work with the layer's attributes. To relate two datasets:

1. Right-click the layer to which you want to join attributes, point to Joins and Relates, and click Relate.
2. Select the relating fields from both layers, and then select a new name for the related layer.
3. Click OK. A new layer will be added to the map.