SQL Server 2008 Spatial, PostgreSQL/PostGIS 1.3
General Overview
FeatureSQL Server 2008 (RC0)MySQL 5.1/6PostgreSQL 8.3/PostGIS 1.3/1.4
OS
Windows XP, Windows Vista, Windows 2003, Windows 2008
Windows XP, Windows Vista, (haven't tested on 2008), Linux, Unix, Mac
Windows 2000+ (including Vista and 2003, haven't tested on 2008), Linux, Unix, Mac
Licensing
Commercial - Closed Source, Various levels of features based on version, Express version has full spatial support but limitation on database size and only use one processor.
Commercial Open Source (COSS), some parts GPL. Here is an interesting blog entry on the subject MySQL free software but not Open Source. The comments are actually much more informative than the article itself.
FLOSS (PostgreSQL is BSD, PostGIS is GPL Open Source - you can use for commercial apps but if you make changes to the core libraries of PostGIS, you need to give that back to the community)
Free GIS Data Loaders
shp dataloader for SQL Server 2008 developed by Morten Nielsen (doesn't yet work with RC0)
OGR2OGR, shp2mysql.pl script
included shp2pgsql, OGR2OGR, QuantumGIS SPIT, SHP loader for PostGIS also developed by Morten using SharpMap.NET various others
Commercial GIS Data Loaders
Manifold, Safe FME Objects, ESRI ArcGIS 9.3 (in a later service pack)
Safe FME Objects
Manifold, FME Objects, ESRI ArcGIS 9.3
Application drivers available specifically for spatial component
? Not yet - SharpMap.NET eventually and probably built into new ADO.NET 3.5+
GDAL C++, SharpMap via OGR, AutoCAD FDO
SharpMap.Net, JDBC postgis.jar included with postgis, JTS etc. tons for Java, GDAL C++, AutoCad FDO beta support
Free Object/Relational Mapping
NHibernateSpatial (this is a .NET object relational spatial mapper) - beta support
Hibernate Spatial - this is a java object relational mapper
NHibernateSpatial and HibernateSpatial
Free Desktop Viewers and Editors
Will be built into SQL Manager, but not available in RC0 and only useful for viewing
GvSig
OpenJump, QuantumGIS, GvSig, uDig
相关文档：
作为备忘吧.在机房里输入的.
/*CREATE TABLE Student
(Sno CHAR(9) PRIMARY KEY,
Sname CHAR(20) UNIQUE,
Ssex CHAR(2),
Sage SMALLINT,
Sdept CHAR(20)
);*/
/*CREATE TABLE Course
(Cno CHAR(4) PRIMARY KEY,
Cname CHAR(40),
Cpno CHAR(4),
Credit SMALLINT,
&n ......
create table #a
(
a int identity(1,1) primary key,
b int default(0) not null,
c nvarchar(20)
)
insert into #a(c)
select 'a' union all
select 'b' union all
select 'c' union all
select 'd' union all
select 'e'
select * from #a
alter table #a drop constraint DF__#a_____________b__12 ......
几个删除重复记录的SQL语句
2009-03-02 10:08
比如现在有一人员表 （表名：peosons）
若想将姓名、身份证号、住址这三个字段完全相同的记录查询出来
select p1.* from persons p1,persons p2 where p1.id<>p2.id &nb ......
装了SQL2000后安装SQL2005,虽然使用别名加以区别了，但发现2005中没有可供访问的类似企业管理器，一时冲动，卸了2000，完整安装了2005，发现还是没有企业管理器，搜索过后才发现需要安装SQLServer2005_SSMSEE.msi（即SQLServerManagerStudioExpressEdition），它提供了类似企业管理器的图形化操作界面。
装好后，SQL ......
联接条件可在 from 或 WHERE 子句中指定，建议在 from 子句中指定联接条件。WHERE 和 HAVING 子句也可以包含搜索条件，以进一步筛选联接条件所选的行。
联接可分为以下几类： ......
