SQLλÔËËã
SQLλÔËËã
select 2|8 --10
select 2|8|1 --11
select 10&8 --8,°üº¬,10=8+2
select 10&2 --2,°üº¬,10=2+8
select 10&4 --0,²»°üº¬
select 19&16 --16,°üº¬,19=16+2+1
select 19&8 --0,°üº¬,19=16+2+1
select * from SqlBitOperation where FBitTags&4=4
ÔÚȨÏÞÖеÄÓ¦ÓÃ
1¡¢Á½Õűí
£¨1£©¡¢²Ù×÷ÓëȨÏÞ±êÖ¾±í
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,'³Ô·¹',1)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 2,'Àʺ',2)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 3,'´òÅÚ',4)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 4,'ÅÝæ¤',8)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 5,'Éú×Ó',16)
INSERT [RightTags] ([Pkid],[RightsName],[RightsTag]) VALUES ( 6,'°ü¶þÄÌ',32)
SET IDENTITY_INSERT [RightTags] OFF
£¨2£©¡¢Óû§ÓëȨÏÞ±í
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
Ïà¹ØÎĵµ£º
TABLE MASTER ×Ö¶Î ID DETAIL.....
TABLE BIZ ×Ö¶Î SYS_ID CODE_ID .......
²éѯʱÐèÒªµÄÊÇIDµÄÃèÊö
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 ......
SQL Server£º
Select TOP N * from TABLE Order By NewID()
Select TOP N * from TABLE Order By NewID()
NewID()º¯Êý½«´´½¨Ò»¸ö uniqueidentifier ÀàÐ͵ÄΨһֵ¡£ÉÏÃæµÄÓï¾äʵÏÖЧ¹ûÊÇ´ÓTableÖÐËæ»ú¶ÁÈ¡NÌõ¼Ç¼¡£
Access£º
Select TOP N *&n ......
----start
¶¯Ì¬SQLÊÇÔÚ³ÌÐòÔËÐÐʱ¹¹ÔìµÄ£¬ÒªÖ´Ðе¥ÌõSQL£¬Ê¹ÓÃEXECUTE IMMEDATE Óï¾ä£»µ±ÅúÁ¿Ö´ÐÐSQLʱ£¬ÏÈʹÓÃPREPARE Óï¾ä¹¹ÔìSQL£¬È»ºóʹÓÃEXECUTE Óï¾äÖ´ÐС£
Ò»£ºPrepareÓï¾ä£ºÓÃÀ´¹¹ÔìÅúÁ¿SQL
Óï·¨£º
PREPARE <sql-statement> [OUTPUT] INTO <result> [INPUT INTO] <input> ......
sql serverºÍoracleÐÐתÁеÄÒ»ÖÖµäÐÍ·½·¨
ǰÑÔ£ºÍøÉÏÓв»ÉÙÎÄÕÂÊǽ²ÐÐתÁе쬵«ÊǴ󲿷ֶ¼ÊÇÖ±½ÓÌù´úÂ룬ºöÊÓÁËÖмä¹ý³Ì£¬±¾ÈË×Ô¼ºË¼¿¼ÁËÏÂΪʲôҪÕâÑùʵÏÖ£¬²¢ÇÒ×öÁËÈçϵıʼǣ¬¶ÔÓÐЩ¶®µÄÈËÀ´Ëµ¿ÉÄÜûÓмÛÖµ£¬Ï£Íû¶Ô»¹²»¶®µÄÈËÓÐÒ»µã½è¼øÒâÒå¡£
¶ÔÓÚÓÐЩҵÎñÀ´Ëµ£¬Êý¾ÝÔÚ±íÖеĴ洢ºÍÆä×îÖÕµÄGrid±íÏÖÇ¡ºÃÏ൱ÓÚ°ÑÔ ......