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'