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Why is it Valid to Concatenate Null Strings but not to Call “null.ToString()”?
...compiler treats a null string the same as an empty string, but it does not convert the value of the original null string.
More information on the + binary operator:
The binary + operator performs string concatenation when one or both operands are of type string.
If an operand of string concatenati...
How can I insert values into a table, using a subquery with more than one result?
...
You want:
insert into prices (group, id, price)
select
7, articleId, 1.50
from article where name like 'ABC%';
where you just hardcode the constant fields.
share
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Is it possible to insert multiple rows at a time in an SQLite database?
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This can be recast into SQLite as:
INSERT INTO 'tablename'
SELECT 'data1' AS 'column1', 'data2' AS 'column2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
a note on performance
I originally used this technique to efficiently lo...
Color different parts of a RichTextBox string
...pendText(this RichTextBox box, string text, Color color)
{
box.SelectionStart = box.TextLength;
box.SelectionLength = 0;
box.SelectionColor = color;
box.AppendText(text);
box.SelectionColor = box.ForeColor;
}
}
And this is how you would use it:
var...
Get average color of image via Javascript
...LUV, but I have not found a good library for this, or any algorythims for converting RGB to LUV.
An entirely different approach would be to sort your colors in a rainbow, and build a histogram with tolerance to account for varying shades of a color. I have not tried this, because sorting colors in...
Ineligible Devices section appeared in Xcode 6.x.x
...6 my devices moved to greyed-out section Ineligible Devices and I can't select them as deploy target:
32 Answers
...
What is the 
 character?
...nce data often contain characters outside the ASCII set, so it has
to be converted into a valid ASCII format.
To find it yourself, you can visit https://en.wikipedia.org/wiki/ASCII, there you can find big tables of characters. The one you are looking is in Control Characters table.
Digging to t...
Select Row number in postgres
How to select row number in postgres.
1 Answer
1
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Socket send函数和recv函数详解以及利用select()函数来进行指定时间的阻塞 ...
Socket send函数和recv函数详解以及利用select()函数来进行指定时间的阻塞int send( SOCKET s, const char FAR *buf, int len, int flags ); 不论是客户还是服务器应用程序都用send函数来向TCP连接的...int send( SOCKET s, const char FAR *buf, int len, int flags );
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Visual Studio hot keys change occasionally, specifically F6 vs Ctrl-Shift-B for building. WHY?
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This is because you might have selected "General Development Settings" as your default environment settings for your Visual Studio (which usually we do on the first launch of VS after installing it as it pops up a dialogue box to choose default environment...