The SYS_KEY_COLUMN_USAGE table contains information to match columns with constraints. It has the following columns:
Column Name  | 
  Data Type  | 
  Description  | 
|---|---|---|
| CONSTRAINT_CATALOG | VARCHAR(128) | Top-level container for constraints. Not used in dotConnect for FreshBooks. Always NULL. | 
| CONSTRAINT_SCHEMA | VARCHAR(128) | Second-level container for constraints. Not used in dotConnect for FreshBooks. Always NULL. | 
| CONSTRAINT_NAME | VARCHAR(128) | The name of the constraint. | 
| TABLE_CATALOG | VARCHAR(128) | Top-level container for tables. Not used in dotConnect for FreshBooks. Always NULL. | 
| TABLE_SCHEMA | VARCHAR(128) | Second-level container for tables. Not used in dotConnect for FreshBooks. Always NULL. | 
| TABLE_NAME | VARCHAR(128) | The name of the FreshBooks object which the field belongs to. | 
| COLUMN_NAME | VARCHAR(128) | The name of a FreshBooks object field. | 
| ORDINAL_POSITION | INT | The position of the field in the key. |