How to determine the primary key for a table in SQL Server?

Question

What I\'d like to be able to do in SQL Server 2005 somehow is with a table name as input determine all the fields that make up the primary key. sp_columns doesn

Answer 1

-- ANSI SQL compatible and works from SQL70 onwards:

select kcu.TABLE_SCHEMA, kcu.TABLE_NAME, kcu.CONSTRAINT_NAME, tc.CONSTRAINT_TYPE, 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 in ( 'PRIMARY KEY', 'UNIQUE' )
 order by kcu.TABLE_SCHEMA, kcu.TABLE_NAME, tc.CONSTRAINT_TYPE, kcu.CONSTRAINT_NAME, kcu.ORDINAL_POSITION;

-- SQL Server 2005 specific:

select s.name as TABLE_SCHEMA, t.name as TABLE_NAME
     , k.name as CONSTRAINT_NAME, k.type_desc as CONSTRAINT_TYPE
     , 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
 order by TABLE_SCHEMA, TABLE_NAME, CONSTRAINT_TYPE, CONSTRAINT_NAME, ORDINAL_POSITION;

Answer 2

In SQL2005 this brings back a row that names the primary key and then gives a list of the column under "index_keys"

sp_help myTable