Question

Write a SELECT statement that selects all of the columns for the catalog view that returns information about foreign keys. How many foreign keys are defined in the AP database?

Answer 1

Answer:

SELECT COUNT (DISTICT constraint_name)

FROM apd_schema.constraint_column_usage

RUN

Explanation:

General syntax to return a catalog view of information about foreign keys.

SELECT DISTINCT PARENT_TABLE =

           RIGHT(Replace(DC.constraint_name, 'fkeys_', ''),

           Len(Replace(DC.constraint_name, 'fkeys_', '')) - Charindex('_', Replace(DC.constraint_name, 'fkeys_', ''))),

           CHILD_TABLE = DC.table_name,

           CCU.column_name,

           DC.constraint_name,

           DC.constraint_type

FROM apd_schema.table_constraints DC

INNER JOIN apd_schema.constraint_column_usage CCU

           ON DC.constraint_name = CCU.constraint_name

WHERE  DC.constraint_type LIKE '%foreign'

           OR DC.constraint_type LIKE '%foreign%'

           OR DC.constraint_type LIKE 'foreign%'

RUN