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Select statement to find duplicates on certain fields
... can use..
select field1,field2,field3, count(*)
from table_name
group by field1,field2,field3
having count(*) > 1
Check this link for more information on how to delete the rows.
http://support.microsoft.com/kb/139444
There should be a criterion for deciding how you define "first rows" bef...
How to use a variable to specify column name in ggplot
...an use aes_string:
f <- function( column ) {
...
ggplot( rates.by.groups, aes_string(x="name", y="rate", colour= column,
group=column ) )
}
as long as you pass the column to the function as a string (f("majr") rather than f(majr)). Also note that...
Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
I'm having a little trouble understanding the pass-by-reference properties of data.table . Some operations seem to 'break' the reference, and I'd like to understand exactly what's happening.
...
Good scalaz introduction [closed]
...recommend you to read through http://apocalisp.wordpress.com/ (blog driven by Runar Oli and Mark Harrah) and the weblog of Tony Morris
UPD: "Functors, Applicative Functors and Monoids" chapter of "Learn You a Haskell for Great Good!" has a lot of examples in Haskell with detailed explanations, whic...
Reverse Range in Swift
...i in (1...5).reversed() { print(i) } // 5 4 3 2 1
Or stride(from:through:by:) method
for i in stride(from:5,through:1,by:-1) { print(i) } // 5 4 3 2 1
stide(from:to:by:) is similar but excludes the last value
for i in stride(from:5,to:0,by:-1) { print(i) } // 5 4 3 2 1
Update For latest Swif...
Are the shift operators () arithmetic or logical in C?
... for those readers unfamiliar with the difference, a "logical" right shift by 1 bit shifts all the bits to the right and fills in the leftmost bit with a 0. An "arithmetic" shift leaves the original value in the leftmost bit. The difference becomes important when dealing with negative numbers.)
Whe...
Which Java Collection should I use?
...Commons Attribution 4.0 International License. The simplest attribution is by linking to either this question or this answer.
Other resources
Probably the most useful other reference is the following page from the oracle documentation which describes each Collection.
HashSet vs TreeSet
There is ...
扩展App Inventor：具有多点触控和手势检测功能 · App Inventor 2 中文网
...s detection, such as two-finger rotation, and user-defined custom gestures by building extension components. Our paper illustrates the implementation of components, sample usage of the components and how they will help novices building apps involving gesture recognition.
KEYWORDS
System, Computer ...
扩展App Inventor：具有多点触控和手势检测功能 · App Inventor 2 中文网
...s detection, such as two-finger rotation, and user-defined custom gestures by building extension components. Our paper illustrates the implementation of components, sample usage of the components and how they will help novices building apps involving gesture recognition.
KEYWORDS
System, Computer ...
扩展App Inventor：具有多点触控和手势检测功能 · App Inventor 2 中文网
...s detection, such as two-finger rotation, and user-defined custom gestures by building extension components. Our paper illustrates the implementation of components, sample usage of the components and how they will help novices building apps involving gesture recognition.
KEYWORDS
System, Computer ...