sysindexes 表中的 status 中记录了哪一个是主键
关键点：status & 2048 = 2048
alter table T_TESTPK lock allpages
select name, indid from sysindexes where id = object_id ('T_TESTPK') and (status & 2048 = 2048)
name indid
---- -----------
PK_TESTPK 1
alter table T_TESTPK lock datarows
select name, indid from sysindexes where id = object_id ('T_TESTPK') and (status & 2048 = 2048)
name indid
---- -----------
PK_TESTPK 3