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Replace a newline in TSQL
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Actually a new line in a SQL command or script string can be any of CR, LF or CR+LF. To get them all, you need something like this:
SELECT REPLACE(REPLACE(@str, CHAR(13), ''), CHAR(10), '')
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When can I use a forward declaration?
...ssuming the following forward declaration.
class X;
Here's what you can and cannot do.
What you can do with an incomplete type:
Declare a member to be a pointer or a reference to the incomplete type:
class Foo {
X *p;
X &r;
};
Declare functions or methods which accept/return inco...
What is the difference between i++ and ++i?
I've seen them both being used in numerous pieces of C# code, and I'd like to know when to use i++ or ++i ( i being a number variable like int , float , double , etc). Anyone who knows this?
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Declaring variables inside loops, good practice or bad practice?
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The compiler knows that the variable scope is limited to inside the loop, and therefore will issue a proper error message if the variable is by mistake referenced elsewhere.
Last but not least, some dedicated optimization can be performed more efficiently by the compiler (most importantly register ...
When to use window.opener / window.parent / window.top
...hen opening a new window that acted as a dialog which required user input, and needed to pass information back to the main window. However this is restricted by origin policy, so you need to ensure both the content from the dialog and the opener window are loaded from the same origin.
window.paren...
Convert LocalDate to LocalDateTime or java.sql.Timestamp
...valid DateTimes. Source: joda-time.sourceforge.net/faq.html#illegalinstant and just running into this.
– Christophe De Troyer
Aug 10 '15 at 8:53
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Converting Mercurial folder to a Git repository
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If you are on Windows machine use the Git bash and run hg-fast-export.sh
– Augustas
Dec 7 '17 at 13:45
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show 7 ...
Differences between Java 8 Date Time API (java.time) and Joda-Time
I know there are questions relating to java.util.Date and Joda-Time. But after some digging, I couldn't find a thread about the differences between the java.time API (new in Java 8 , defined by JSR 310 ) and Joda-Time .
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HEAD and ORIG_HEAD in Git
What do these symbols refer to and what do they mean?
4 Answers
4
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Does MySQL ignore null values on unique constraints?
...sult:
x
NULL
NULL
1
This is not true for all databases. SQL Server 2005 and older, for example, only allows a single NULL value in a column that has a unique constraint.
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