CONSTRAINT_TABLE_USAGE
Applies to:  Databricks SQL 
 Databricks Runtime 11.3 LTS and above 
 Unity Catalog only
This feature is in Public Preview.
INFORMATION_SCHEMA.CONSTRAINT_TABLE_USAGE lists all constraints that reference a table as either a foreign or primary key within the catalog.
The rows returned are limited to the tables the user is privileged to interact with.
Definition
The CONSTRAINT_TABLE_USAGE relation contains the following columns:
Name  | Data type  | Nullable  | Standard  | Description  | 
|---|---|---|---|---|
  | 
  | No  | Yes  | Catalog containing the relation.  | 
  | 
  | No  | Yes  | Schema containing the relation.  | 
  | 
  | No  | Yes  | Name of the relation.  | 
  | 
  | No  | Yes  | Catalog containing the constraint.  | 
  | 
  | No  | Yes  | Schema containing the constraint.  | 
  | 
  | No  | Yes  | Name of the constraint.  | 
Constraints
The following constraints apply to the CONSTRAINT_TABLE_USAGE relation:
Class  | Name  | Column List  | Description  | 
|---|---|---|---|
Primary key  | 
  | 
  | Uniquely identifies the relation.  | 
Foreign key  | 
  | 
  | References TABLES  | 
Foreign key  | 
  | 
  | References TABLE_CONSTRAINTS.  | 
Examples
> SELECT constraint_name
    FROM information_schema.constraint_table_usage
    WHERE table_schema = 'information_schema'
      AND table_name = 'tables'