SqlServer有多种找到SqlServer主键的方法，接下来的SQL server内容就为您介绍其中的四种，供您参考学习，其中的第一、二中种方法是最为简单的。
1:利用SQL自带的存储过程找到SqlServer主键
EXEC sp_pkeys @table_name='表名'
2:利用系统表INFORMATION_SCHEMA.KEY_COLUMN_USAGE 找到SqlServer主键
SELECT TABLE_NAME,COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE TABLE_NAME='表名'
3: 以下这个查询表结构的语句可能大家都见过：
利用syscolumns,sysindexes,sysindexkeys三个表关联可以查出SqlServer主键
SELECT (case when a.colorder=1 then d.name else '' end) N'表名', a.colorder N'字段序号', a.name N'字段名', (case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end) N'标识', (case when (SELECT count(*) FROM sysobjects WHERE (name in (SELECT name FROM sysindexes WHERE (id = a.id) AND (indid in (SELECT indid FROM sysindexkeys WHERE (id = a.id) AND (colid in (SELECT colid FROM syscolumns WHERE (id = a.id) AND (name = a.name))))))) AND (xtype = 'PK'))>0 then '√' else '' end) N'主键', b.name N'类型', a.length N'占用字节数', COLUMNPROPERTY(a.id,a.name,'PRECISION') as N'长度', isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0) as N'小数位数', (case when a.isnullable=1 then '√'else '' end) N'允许空', isnull(e.text,'') N'默认值', isnull(g.[value],'') AS N'字段说明' --into ##tx FROM syscolumns a left join systypes b on a.xtype=b.xusertype inner join sysobjects d on a.id=d.id and d.xtype='U' and d.name<>'dtproperties' left join syscomments e on a.cdefault=e.id left join sysproperties g on a.id=g.id AND a.colid = g.smallid order by object_name(a.id),a.colorder
4:
select o.name as 表名,c.name as 字段名,k.colid as 字段序号,k.keyno as 索引顺序 from sysindexes i join sysindexkeys k on i.id = k.id and i.indid = k.indid join sysobjects o on i.id = o.id join syscolumns c on i.id=c.id and k.colid = c.colid where o.xtype = 'U' and exists(select 1 from sysobjects where xtype = 'PK' and name = i.name) order by o.name,k.colid