J'utilise ceci dans un générateur de code que j'ai écrit pour obtenir la clé primaire :
SELECT i.name AS IndexName,
OBJECT_NAME(ic.OBJECT_ID) AS TableName,
COL_NAME(ic.OBJECT_ID,ic.column_id) AS ColumnName,
c.is_identity, c.user_type_id, CAST(c.max_length AS int) AS max_length,
CAST(c.precision AS int) AS precision, CAST(c.scale AS int) AS scale
FROM sys.indexes AS i
INNER JOIN sys.index_columns AS ic
INNER JOIN sys.columns AS c ON ic.object_id = c.object_id AND ic.column_id = c.column_id
ON i.OBJECT_ID = ic.OBJECT_ID AND i.index_id = ic.index_id
WHERE i.is_primary_key = 1 AND ic.OBJECT_ID = OBJECT_ID('dbo.YourTableNameHere')
ORDER BY OBJECT_NAME(ic.OBJECT_ID), ic.key_ordinal
