En SQL Server puedes hacer
SELECT K.TABLE_CATALOG,
K.TABLE_NAME,
K.COLUMN_NAME,
K.ORDINAL_POSITION
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE K
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS TC
ON K.TABLE_CATALOG = TC.TABLE_CATALOG
AND K.TABLE_SCHEMA = TC.TABLE_SCHEMA
AND K.CONSTRAINT_NAME = TC.CONSTRAINT_NAME
WHERE TC.CONSTRAINT_TYPE = 'PRIMARY KEY'
o
SELECT Object_name(C.OBJECT_ID) TABLE_NAME,
C.NAME,
IC.INDEX_COLUMN_ID
FROM SYS.KEY_CONSTRAINTS K
INNER JOIN SYS.INDEX_COLUMNS IC
ON K.PARENT_OBJECT_ID = IC.OBJECT_ID
AND K.UNIQUE_INDEX_ID = IC.INDEX_ID
INNER JOIN SYS.COLUMNS C
ON IC.OBJECT_ID = C.OBJECT_ID
AND IC.COLUMN_ID = C.COLUMN_ID
WHERE K.TYPE = 'PK'
EN ORÁCULO
SELECT K.OWNER,
K.TABLE_NAME,
K.INDEX_NAME,
C.COLUMN_NAME,
C.COLUMN_POSITION
FROM ALL_CONSTRAINTS K
INNER JOIN ALL_IND_COLUMNS C
ON K.OWNER = C.INDEX_OWNER
AND K.TABLE_NAME = C.TABLE_NAME
AND K.INDEX_NAME = C.INDEX_NAME
WHERE K.CONSTRAINT_TYPE = 'P'
