PostgreSQL 18 Documentation

35.32. key_column_usage

key_column_usage

The view key_column_usage identifies all columns in the current database that are restricted by some unique, primary key, or foreign key constraint. Check constraints are not included in this view. Only those columns are shown that the current user has access to, by way of being the owner or having some privilege.

Column Type

Description

constraint_catalog sql_identifier

Name of the database that contains the constraint (always the current database)

constraint_schema sql_identifier

Name of the schema that contains the constraint

constraint_name sql_identifier

Name of the constraint

table_catalog sql_identifier

Name of the database that contains the table that contains the column that is restricted by this constraint (always the current database)

table_schema sql_identifier

Name of the schema that contains the table that contains the column that is restricted by this constraint

table_name sql_identifier

Name of the table that contains the column that is restricted by this constraint

column_name sql_identifier

Name of the column that is restricted by this constraint

ordinal_position cardinal_number

Ordinal position of the column within the constraint key (count starts at 1)

position_in_unique_constraint cardinal_number

For a foreign-key constraint, ordinal position of the referenced column within its unique constraint (count starts at 1); otherwise null

: key_column_usage Columns