P1:天文数据获取
Step1:在sloan的casjob里http://casjobs.sdss.org/CasJobs/，密码用户 jiangbin 123456
查询满足条件的光谱对象，得到光谱对象的plate,MJD,fiber，或者赤经赤纬，将其存为.csv文件。Csv文件可由excel直接编辑，注意要调整顺序为plate,MJD,fiberid,excel文件第一行要保留这几个关键字。点击quick不要点击sumbit按钮
Step2:在sloan的http://das.sdss.org/www/html/post_fibers.html，提交.csv文件（此处也可以是txt文件，见cvs文件夹下txt），
Step3:点击this form链接，出现Download selection，选择要下载的文件类型，此处选择spSpec。再选中wget，提交。
Step4：提交后会出现一个URL列表，另存为.txt文件,比如为D:\url.txt，此处可以手工修改。
Step5:开始－>运行－>cmd,进入dos窗口，输入：wget -i D:\url.txt（wget -i G:\DATA\sdss-wget-awrOed.lis），回车。
之后就开始批量下载了，下载到dos窗口的当前目录下。
选取5000条star
select top 5000 plate,MJD,fiberID from specobjall where class='star' and waveMin <= 4000 and waveMax >= 9000
选取后5000条数据
select top 10000 plate,MJD,fiberID from specobjall where class='star' and waveMin <= 4000 and waveMax >= 9000
except
select top 5000 plate,MJD,fiberID from specobjall where class='star' and waveMin <= 4000 and waveMax >= 9000
类别：
Qso
Galaxy
select plate,MJD,fiberID from specobjall where subClass like 'M[0-9]' and snMedian_g>=15
select plate,MJD,fiberID from specobjall where subClass like 'M[0-9]' and snMedian_g>=15
2. 获取激变变星搜寻群（目前只有DR7是开放的，不要从DR15里搜）
select plate,mjd,fiberID from SpecPhotoAll into mydb.patrick
where psfMag_u-psfMag_g<0.45
and psfMag_g-psfMag_r<0.7
and psfMag_r-psfMag_i>0.3
and psfMag_i-psfMag_z>0.4
select top 8000 plate,mjd,fiberID from patrick
delete top(8000) from patrick
3. Casjob网站：http://casjobs.sdss.org/CasJobs/
4. Sloan提交csv网站：http://das.sdss.org/www/html/post_fibers.html
5. 下载数据方法：wget -i txt文件的路径
6. DR7类别：http://cas.sdss.org/dr7/de/help/browser/enum.asp?n=SpecClass
7. DR7帮助：https://classic.sdss.org/dr7/glossary/index.html
8. 按类别搜索DR7中的反例：
select top 8000 plate,mjd,fiberID from specobjall where specClass=1 order by newid() /*specClass=1: STAR*/
select top 4000 plate,mjd,fiberID from specobjall where specClass=2 order by newid() /*specClass=2: GALAXY*/
select top 4000 plate,mjd,fiberID from specobjall where specClass=3 order by newid() /*specClass=3: QSO*/
select top 4000 plate,mjd,fiberID from specobjall where specClass=4 or specClass=5 or specClass=6 or specClass=0 order by newid() /*specClass=0,4,5,6: OTHER*/
