SQL位运算
SQL位运算
select 2|8 --10
select 2|8|1 --11
select 10&8 --8,包含,10=8+2
select 10&2 --2,包含,10=2+8
select 10&4 --0,不包含
select 19&16 --16,包含,19=16+2+1
select 19&8 --0,包含,19=16+2+1
select * from SqlBitOperation where FBitTags&4=4
在权限中的应用
1、两张表
（1）、操作与权限标志表
if exists (select * from sysobjects where id = OBJECT_ID('[RightTags]') and OBJECTPROPERTY(id, 'IsUserTable') = 1)
DROP TABLE [RightTags]
CREATE TABLE [RightTags] (
[Pkid] [int] IDENTITY (1, 1) NOT NULL,
[RightsName] [nvarchar] (50) NOT NULL,
[RightsTag] [int] NOT NULL DEFAULT (0))
ALTER TABLE [RightTags] WITH NOCHECK ADD CONSTRAINT [PK_RightTags] PRIMARY KEY NONCLUSTERED ( [Pkid] )
SET IDENTITY_INSERT [RightTags] ON
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 1,'吃饭',1)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 2,'拉屎',2)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 3,'打炮',4)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 4,'泡妞',8)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 5,'生子',16)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 6,'包二奶',32)
SET IDENTITY_INSERT [RightTags] OFF
（2）、用户与权限表
if exists (select * from sysobjects where id = OBJECT_ID('[RightUsers]') and OBJECTPROPERTY(id, 'IsUserTable') = 1)
DROP TABLE [RightUsers]
CREATE TABLE [RightUsers] (
[Pkid] [int] IDENTITY (1, 1) NOT NULL,
[FUser] [nvarchar] (50) NOT NULL,
[UserRights] [int] NOT NULL DEFAULT (0))
ALTER TABLE [RightUsers] WITH NOCHECK ADD CONSTRAINT [PK_RightUsers] PRIMARY KEY NONCLUSTERED ( [Pkid] )
SET IDENTITY_INSERT [RightUsers] ON
INSERT [RightUsers] ([Pkid],[FUser],[UserRights]) VALUES ( 1
相关文档：
TABLE MASTER 字段 ID DETAIL.....
TABLE BIZ 字段 SYS_ID CODE_ID .......
查询时需要的是ID的描述
1,SELECT A.SYS_ID,A.CODE_ID,B.DETAIL,C.DETAIL...... from BIZ A,MASTER B,MASTER C WHERE A.SYS_ID=B.ID AND A.CODE_ID=C.ID
2,SELECT SYS_ID,(SELECT DETAIL from MASTER ......
alter table 表名
add constraint 约束名
foreign key(字段名) references 主表名(字段名)
on delete cascade
语法：
Foreign Key
(column[,...n])
references referenced_table_name[(ref_column[,...n])]
[on delete cascade]
[on update cascade]
注释：
column:列名
referenced_table_name:外键参考的主键� ......
select name from syscolumns where id in (select id from sysobjects where type = 'u' and name = '相应表名')
用以上sql语句输入相应表名就可以查到表的字段名，对应好数据库 查询是否存在该表语句
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[tb_cost]') and OBJECTPROPER ......
1、查询表中重复数据。select * from people
where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1)
2、删除表中多余的重复记录，重复记录是根据� ......
for ACCESS :
update a, b set a.name=b.name1 where a.id=b.id
for SQL Server:
"update a set a.name=b.name1 from a,b where a.id=b.id"
update a set a.status=b.status
from table1 a,table2 b
&nbs ......
