Notes on the BITAND Function
The current implementation of BITAND defines n = 128.
PL/SQL supports an overload of BITAND for which the types of the inputs and of the result are all BINARY_INTEGER and for which n = 32.
结论：如果要在pl/sql里面对超过32位的数做bitand，不能用result:=bitand(a,b);而要用select bitand(a,b) into result from dual;
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【相关环境】
操作系统：Win8.1 Pro 64bit
IDE：Visual Studio 2012
【准备工作】
要在Windows环境下编译MySQL的源码，需要做一些准备工作：
1. 在C盘（若其他盘下）建立新的文件夹：MySQLSC
2. 下载MySQL的源码是必须的，我是到MySQL官网下载了：mysql-5.7.3-m13.zip
3. 需要安装几个软件，包括：ActivePerl、CMake、GNUBison、bzr
4. 为便于大家学习，我将需要的软件打包提供，可点下面的链接下载：
=====================...
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摘自《Cody's data cleaning techniques using sas》
libname clean "c:/books/clean"; /*定义永久性数据库*/
*新建一个样本数据one;
data one;
input X Y Z;
datalines;
1 2 3
101 202 303
44 55 66
444 555 666
;
title "Values of X from data set ONE where X is greater than 100";
/*有条件的选择观测值*/
proc sql;
select X
from one
where X gt 100; ...
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代码摘录自：《Getting Your Random Sample in Proc SQL》
libname yugao "C:/BOOKS" ;data yugao.sample; format rec_no 7.0 age 4.0 sex $6. ; label rec_no = "Record Number / ID" age = "Age in Years" sex = "Gender" norm01_rv = "RV N(0,1)" uni01_rv = "RV U(0,1)" ; do i=1 to 1000000 ; /* one million records */ rec_no = i ; /* unique record identifier */ n...
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1.逻辑表达：>,<,!=,....
*data step;
data class_flags;
set sashelp.class;
tall = (height > 60);
male = (sex = 'M');
female = (sex = 'F');
run;
*proc sql;
proc sql;
select name,
(height > 60) as tall,
(sex = 'M') as male,
(sex = 'F') as female
from sashelp.class;
quit;
2.描述性统计函数sum(),mean(),....
proc sql;
sel...
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proc sql;
select name,sex,age,weight,height,
case
when height> 65 then "Tall"
when height < 60 then "Short"
else "Average Height"
end as New_height
from sashelp.class;
quit;
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朱世武的书<SAS 编程技术>的例子很详细,现在想想基本上涵盖了一些论坛上的问题.
/*21.1.1 简单连接*/
proc sql;
select * from resdat.china, resdat.usa;
quit
/*21.1.3 内部连接*/
proc sql;
select * from resdat.china, resdat.usa
where china.level=usa.level;
quit;
/*21.1.3.1 使用表的别名*/
proc sql;
select * from resdat.china as a, resdat.usa as b
where a.level=b.level;
quit;
/*21.1.3.2 使用别名...
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