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 ......
SQL 中的 substring 函数是用来抓出一个栏位资料中的其中一部分。这个函数的名称在不同的资料库中不完全一样：
MySQL: SUBSTR(), SUBSTRING()
Oracle: SUBSTR()
SQL Server: SUBSTRING()
最常用到的方式如下 (在这里我们用SUBSTR()为例)：
SUBSTR(str,pos): 由<str>中，选出所有从第<pos>位置开始 ......
ORDER BY 排序
ASC 升序(默认)
DESC 降序
select * from s_emp order by dept_id , salary desc
部门号升序，工资降序
关键字distinct也会触发排序操作。
select * from employee order by 1; //按第一字段排序
NULL被认为无穷大。order by 可以跟别名。
select table_name ......
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 ......
