select * 
from INFORMATION_SCHEMA.CONSTRAINT_TABLE_USAGE  a
left outer join INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE b on b.CONSTRAINT_NAME = a.CONSTRAINT_NAME
left outer join INFORMATION_SCHEMA.CHECK_CONSTRAINTS c on c.CONSTRAINT_NAME = a.CONSTRAINT_NAME
left outer join INFORMATION_SCHEMA.TABLE_CONSTRAINTS d on d.CONSTRAINT_NAME = a.CONSTRAINT_NAME

select a.CONSTRAINT_NAME, b.column_name
from INFORMATION_SCHEMA.TABLE_CONSTRAINTS a
inner join INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE b on a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
where a.CONSTRAINT_TYPE = 'PRIMARY KEY'

select a.constraint_name, a.table_name as FK_Table, a.column_name AS FK_column,c.table_name AS PK_Table, c.column_name AS PK_column
from INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE a 
inner join INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS b on b.constraint_name = a.constraint_name
inner join INFORMATION_SCHEMA.KEY_COLUMN_USAGE c on c.constraint_name = b.unique_constraint_name

select *
from
(select a.table_catalog AS A_Catalog, a.table_name AS A_table, a.CONSTRAINT_NAME AS A_CONSTRAINT_NAME, b.column_name AS A_Column_name
from pubs.INFORMATION_SCHEMA.TABLE_CONSTRAINTS a
inner join pubs.INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE b on a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
where a.CONSTRAINT_TYPE = 'PRIMARY KEY' ) a
left outer join 
OPENQUERY(mylinkedserver, 'select a.table_catalog AS B_Catalog, a.table_name AS B_table, a.CONSTRAINT_NAME AS B_CONSTRAINT_NAME, b.column_name AS B_Column_name
from pubs.INFORMATION_SCHEMA.TABLE_CONSTRAINTS a
inner join pubs.INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE b on a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
where a.CONSTRAINT_TYPE = ''PRIMARY KEY''') b 
ON b.table_catalog = a.table_catalog AND b.table_name= a.table_name

ON b.b_catalog = a.a_catalog AND b.b_table= a.a_table

SELECT *
FROM
	(SELECT 
		a.table_catalog AS A_Catalog, 
		a.table_name AS	A_table,
		a.CONSTRAINT_NAME AS A_CONSTRAINT_NAME, 
		b.column_name AS A_Column_name
	FROM 
		TEST1.INFORMATION_SCHEMA.TABLE_CONSTRAINTS a
	INNER JOIN 
		TEST1.INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE b 
	ON 
		a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
	WHERE 
		a.CONSTRAINT_TYPE = 'FOREIGN KEY' 
	) a
 
LEFT OUTER JOIN
OPENQUERY
	(SERVER_my 
		'SELECT 
		a.table_catalog AS B_Catalog, 
		a.table_name AS B_table, 
		a.CONSTRAINT_NAME AS B_CONSTRAINT_NAME, 
		b.column_name AS B_Column_name
	FROM 
		TEST2.INFORMATION_SCHEMA.TABLE_CONSTRAINTS a
	INNER 
		JOIN TEST2.INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE b ON a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
	WHERE 
		a.CONSTRAINT_TYPE = ''FOREIGN KEY''') b 
ON b.b_table= a.a_table