方法较多:
一、
EXEC sp_pkeys @table_name='tab'
二、
SELECT TABLE_NAME, COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE TABLE_NAME='tabl'
三、
SELECT A.NAME AS 表名,B.NAME AS 主键名 FROM SYSOBJECTS A JOIN SYSOBJECTS B ON A.ID=B.PARENT_OBJ AND A.XTYPE='U' AND B.XTYPE='PK'