对数据进行分组的SQL

Posted by & filed under Access.

Table:

idscore
156
291
367
454
556
669
761
883
999
Subject_table

MS Access

SELECT Switch(score < 60,  "less 60",
        	score < 80,  "60 - 80",
        	score < 100 , 

Strings and Manipulations(VBA)

Posted by & filed under Access.

Text Functions, Workbook
Before continuing please be aware of the following information available in Excel HELP

FIND(find_text,within_text,start_num)
Worksheet Description VBA
CHAR Returns the character specified by the code number CHR
CLEAN Removes all nonprintable characters from text
Characters 0-31, 129, …

标准差和方差

Posted by & filed under DATABASE.

标准差

标准差是数值分散的测量。

标准差的符号是 σ (希腊语字母 西格马,英语 sigma)

公式很简单:方差平方根。那么…… “方差是什么?”

方差

方差的定义是:

离平均的平方距离的平均。

按照以下的步骤来计算方差:

例子

你和朋友们量度了狗狗的身高(毫米):
狗图肩高

身高(到肩膀)是:600mm、470mm、170mm、430mm 和 300mm。

求平均、方差和标准差。

第一步是求平均:

答案:

平均  =  600 + 470

Access 2007 SQL the default value for switch

Posted by & filed under Access.

I am using switch statement in access 2007, i want to know how I can specify default value.
select
switch
(
MyCol = 1, ‘Value is One’,
MyCol = 2, ‘Value is Two’
) from MyTable
-

SELECT
Switch(MyTable.[MyCol]=’1′,’Terrestrial’,
MyTable.[MyCol]=’2′,’Value …