SQL Server查询主键约束

SQL70版本，新版本向下兼容：

select kcu.TABLE_SCHEMA, kcu.TABLE_NAME, kcu.CONSTRAINT_NAME, kcu.COLUMN_NAME, kcu.ORDINAL_POSITION
  from INFORMATION_SCHEMA.TABLE_CONSTRAINTS as tc
  join INFORMATION_SCHEMA.KEY_COLUMN_USAGE as kcu
    on kcu.CONSTRAINT_SCHEMA = tc.CONSTRAINT_SCHEMA
   and kcu.CONSTRAINT_NAME = tc.CONSTRAINT_NAME
   and kcu.TABLE_SCHEMA = tc.TABLE_SCHEMA
   and kcu.TABLE_NAME = tc.TABLE_NAME
 where tc.CONSTRAINT_TYPE = 'PRIMARY KEY';

SQL2005以后的查询SQL：

select s.name as TABLE_SCHEMA, t.name as TABLE_NAME, k.name as CONSTRAINT_NAME, c.name as COLUMN_NAME, ic.key_ordinal AS ORDINAL_POSITION
  from sys.key_constraints as k
  join sys.tables as t
    on t.object_id = k.parent_object_id
  join sys.schemas as s
    on s.schema_id = t.schema_id
  join sys.index_columns as ic
    on ic.object_id = t.object_id
   and ic.index_id = k.unique_index_id
  join sys.columns as c
    on c.object_id = t.object_id
   and c.column_id = ic.column_id
 where k.type = 'PK';