根据表面查询主键名

SELECT syscolumns.name
FROM syscolumns,sysobjects,sysindexes,sysindexkeys
WHERE syscolumns.id = object_id('PDM_RouteDetail') AND sysobjects.xtype = 'PK'
AND sysobjects.parent_obj = syscolumns.id
AND sysindexes.id = syscolumns.id
AND sysobjects.name = sysindexes.name AND sysindexkeys.id = syscolumns.id
AND sysindexkeys.indid = sysindexes.indid
AND syscolumns.colid = sysindexkeys.colid