They normally prefix temporary tables.

From the [docs](https://msdn.microsoft.com/en-us/library/ms174979.aspx)....

&gt; Prefix local temporary table names
&gt; with single number sign (#table_name),
&gt; and prefix global temporary table
&gt; names with a double number sign
&gt; (##table_name).

The pound sign `#` is used to prefix [temporary tables][1] and [procedures][2]. A single instance (`#`) refers to a temporary object that lives/dies with the current session while a double instance (`##`) is a global object.


  [1]: http://www.sqlteam.com/article/temporary-tables
  [2]: http://www.petefreitag.com/item/459.cfm

The other answers are correct if you&#39;re dealing with SQL Server, and it&#39;s clear that you are. But since the question title just says SQL, I should mention that there are some forms of SQL such as MySQL where a pound sign is used as an alternative commenting symbol.

    #This is a comment.

https://dev.mysql.com/doc/refman/5.7/en/comments.html

You could be seeing the # in the usage of a temporary table


    SELECT
      *
    FROM #myTempTable



*#TEMPTABLE. Its actually a type of a temporary table that is scoped for that session.*

I&#39;m trying to learn Fortran and I&#39;m seeing a lot of different definitions being passed around and I&#39;m wondering if they&#39;re trying to accomplish the same thing. What is the difference between the following?

 - `integer*4` 
 - `integer(4)` 
 - `integer(kind=4)`

 

Fortran: integer*4 vs integer(4) vs integer(kind=4)

&gt; **Possible Duplicate:**  
&gt; [Weird Java Boxing](https://stackoverflow.com/questions/3130311/weird-java-boxing)  

&lt;!-- End of automatically inserted text --&gt;
Recently I saw a presentation where was the following sample of Java code:

    Integer a = 1000, b = 1000;  
    System.out.println(a == b); // false  
    Integer c = 100, d = 100;  
    System.out.println(c == d); // true

Now I&#39;m a little confused. I understand why in first case the result is &quot;false&quot; - it is because Integer is a reference type and the references of &quot;a&quot; and &quot;b&quot; is different.

But why in second case the result is &quot;true&quot;?

I&#39;ve heard an opinion, that JVM caching objects for int values from -128 to 127 for some optimisation purposes. In this way, references of &quot;c&quot; and &quot;d&quot; is the same.

Can anybody give me more information about this behavior? I want to understand purposes of this optimization. In what cases performance is increased, etc. Reference to some research of this problem will be great.

Integers caching in Java

Can someone please explain to me what the **`#`** symbol means in MS SQL Code.

I&#39;ve tried Googling it, and even searching on StackOverflow, but can&#39;t seem to find the answer.

I feel like an idiot - having one of &quot;those&quot; days. Please help.

What does the SQL # symbol mean and how is it used?

Can someone please explain to me what the <code>#</code> symbol means in MS SQL Code.
I've tried Googling it, and even searching on StackOverflow, but can't seem to find the answer.
I feel like an idiot - having one of "those" days. Please help.

I came across an old table today with a datetime column called &#39;Created&#39; which allows nulls.  Now, I&#39;d want to change this so that it is NOT NULL, and also include a constraint to add in a default value (getdate()).

So far I&#39;ve got the following script, which works fine provided that i&#39;ve cleaned up all the nulls beforehand:

    ALTER TABLE dbo.MyTable ALTER COLUMN Created DATETIME NOT NULL 

Is there any way to also specify the default value as well on the ALTER statement?

Change a Nullable column to NOT NULL with Default Value

Is it possible to easily round a figure &lt;b&gt;up&lt;/b&gt; to the nearest 100 (or 1000, 500, 200 etc.) in SQL Server?

So:

720 -&gt; 800&lt;br/&gt;
790 -&gt; 800&lt;br/&gt;
1401 -&gt; 1500&lt;br/&gt;

Round *UP* to the nearest 100 in SQL Server

What is the difference between CROSS JOIN and FULL OUTER JOIN in SQL Server?

Are they the same, or not? Please explain. When would one use either of these?

SQL Server: What is the difference between CROSS JOIN and FULL OUTER JOIN?

Could someone give me a quick overview of the pros and cons of using the following two statements:

    TRUNCATE TABLE dbo.MyTable

vs

    DELETE FROM dbo.MyTable

It seems like they both do the same thing when all is said and done; but are there must be differences between the two.



Pros &amp; Cons of TRUNCATE vs DELETE FROM

I have a stored procedure that has a bunch of input and output parameters because it is Inserting values to multiple tables.  In some cases the stored proc only inserts to a single table (depending on the input parameters).  Here is a mocked up scenario to illustrate.

Tables / Data Objects:

**Person**

    Id
    Name
    Address

**Name**

    Id
    FirstName
    LastName

**Address**

    Id
    Country
    City

Say I have a stored procedure that inserts a person. If the address doesn&#39;t exist I won&#39;t add it to the `Address` table in the database.  

Thus when I generate the code to call the stored procedure I don&#39;t want to bother adding the `Address` parameter. For `INPUT` parameters this is ok because SQL Server allows me to supply default values. But for the `OUTPUT` parameter what do I do in the stored procedure to make it optional so I do not receive an error...

&gt; *Procedure or function &#39;Person_InsertPerson&#39; expects parameter
&gt; &#39;@AddressId&#39;, which was not supplied.*

Can I have an optional OUTPUT parameter in a stored procedure?

I&#39;ve noticed the following code is legal in Python. My question is why? Is there a specific reason?

    n = 5
    while n != 0:
        print n
        n -= 1
    else:
        print &quot;what the...&quot;

Else clause on Python while statement

I was recently comparing the current version of [json2.js][1] with the version I had in my project and noticed a difference in how the function expression was created and self executed.

The code used to wrap an anonymous function in parenthesis and then execute it,

    (function () {
      // code here
    })();

but now it wraps the auto-executed function in parenthesis.

    (function () {
      // code here
    }());

There is a comment by CMS in the accepted answer of [Explain JavaScript’s encapsulated anonymous function syntax][2] that “both: `(function(){})();` and `(function(){}());` are valid.”

I was wondering what the difference is?  Does the former take up memory by leaving around a global, anonymous function?  Where should the parenthesis be located?


  [1]: https://github.com/douglascrockford/JSON-js/blob/master/json2.js
  [2]: https://stackoverflow.com/questions/1634268/explain-javascripts-encapsulated-anonymous-function-syntax

Location of parenthesis for auto-executing anonymous JavaScript functions?

I expected the following to work but it doesn&#39;t seem to.

    &lt;?php
    
    class Patterns
    {
    	public static const EMAIL = &quot;/^([a-z0-9\+_\-]+)(\.[a-z0-9\+_\-]+)*@([a-z0-9\-]+\.)+[a-z]{2,6}$/ix&quot;;
    	public static const INT = &quot;/^\d+$/&quot;;
    	public static const USERNAME = &quot;/^\w+$/&quot;;
    }

Because it throws this error:

    syntax error, unexpected T_CONST, expecting T_VARIABLE

Can you use static constants inside classes in PHP?

I have a string that looks like `&#39;%s in %s&#39;` and I want to know how to seperate the arguments so that they are two different %s. My mind coming from Java came up with this: 

    &#39;%s in %s&#39; % unicode(self.author),  unicode(self.publication)

But this doesn&#39;t work so how does it look in Python?


Using multiple arguments for string formatting in Python (e.g., &#39;%s ... %s&#39;)

Is it possible to have guards on lambda functions?

For example:

    \k
        | k &lt; 0     -&gt; &quot;negative&quot;
        | k == 0    -&gt; &quot;zero&quot;
        | otherwise -&gt; &quot;positive&quot;



Haskell guards on lambda functions?

During a refactor of an iOS project, I ran into this bear of a bug. During the linking phase, I get this message:

&gt;ld: duplicate symbol _OBJC_IVAR_$_TinCanViewController.currentViewController in /path/to/TinCanViewController-E98A666B7AF2673A.o and /path/to/TinCanViewController-E98A666B7AF2673A.o

As far as I can tell, it looks like it claims `TinCanViewController-E98A666B7AF2673A.o` is declaring the specified symbol twice; both paths are pointing to the exact same .o file. I ran `nm` on that specific file, and it only included that symbol once: 

&gt; 00008150 S _OBJC_IVAR_$_TinCanViewController.currentViewController

I ran `nm` on all the other .o files in the directory to see if they were somehow declaring this symbol, too, but they&#39;re not. This happens to any member I add to the TinCanViewController class - it&#39;s not specific to currentViewController.

I feel like I must be somehow linking against the class twice somehow, but I&#39;ve pretty assiduously gone through and checked all references to this class. In the refactored version, there are basically none. The AppDelegate includes it, but right now it&#39;s basically just a passthrough class that loads another ViewController at the start. No other classes in the project include it.

Any suggestions on what might be causing this or how I might debug it better?


Duplicate symbol issues

I&#39;m trying to figure out whether I can build a static library that hides all of its internal objects and functions, etc, except for the interfaces I want to export. I&#39;m experimenting with Xcode (gcc 4.2).

I&#39;ve used the `__attribute__((visibility(&quot;hidden&quot;)))` attribute on some C++ classes per [this documentation][1]. I&#39;ve also defined little helper C functions as being file-local (static), etc.

However, when I run `strings` on the resulting .a library file, even when compiled in Release configuration, I still see the names of my ostensibly-hidden classes, with their method names, and even the names of file-local functions strewn around in there as well. 

I&#39;ve added the `-fvisibility=hidden` and even `-fno-rtti` to the gcc flags. While this reduces some of the strings, the class names, method names, and static functions names are all still in there in plain or mangled-but-readable form. 

Is there a reliable way to get the compiler to build this stuff without having the string names of all the internal stuff emitted into the binary? It shouldn&#39;t be necessary to have for any external clients linking in.

(To clarify: I&#39;m asking about obfuscation of internal naming, versus literal export binding needs. I&#39;m disconcerted that all the internal workings are visible via the `strings` command, regardless of whether these symbols are formally exported or not.)

Thanks.

  [1]: http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/CppRuntimeEnv/Articles/SymbolVisibility.html

Symbol hiding in static libraries built with Xcode

I&#39;d like to trace some code in GIMP and therefore need GIMP with debug symbols enabled. I don&#39;t remember whether I have enabled them during compilation. How to check that without recompiling the program?

How to check if program was compiled with debug symbols?

Is there a tool for reading Mac OS X binaries that would print information about relocation tables and symbol offsets similar to this `readelf` output?

    readelf -r app
    
    Relocation section &#39;.rel.dyn&#39; at offset 0x5ec contains 2 entries:
     Offset     Info    Type            Sym.Value  Sym. Name
    08049d58  00001706 R_386_GLOB_DAT    00000000   __gmon_start__
    08049d60  00000305 R_386_COPY        08049d60   _ZSt4cout
    
    Relocation section &#39;.rel.plt&#39; at offset 0x5fc contains 13 entries:
     Offset     Info    Type            Sym.Value  Sym. Name
    08049d24  00000107 R_386_JUMP_SLOT   0804868c   print
    08049d28  00000207 R_386_JUMP_SLOT   0804869c   _ZNSt8ios_base4InitC1E
    08049d2c  00000507 R_386_JUMP_SLOT   080486ac   _ZStlsISt11char_traits
    08049d30  00000607 R_386_JUMP_SLOT   080486bc   _ZNSolsEPFRSoS_E
    08049d34  00000707 R_386_JUMP_SLOT   08048664   _init
    08049d38  00000807 R_386_JUMP_SLOT   080486dc   sleep
    08049d3c  00000907 R_386_JUMP_SLOT   080486ec   _ZNKSsixEj
    08049d40  00000b07 R_386_JUMP_SLOT   080486fc   _ZNKSs4sizeEv
    08049d44  00000c07 R_386_JUMP_SLOT   0804870c   __libc_start_main
    08049d48  00000d07 R_386_JUMP_SLOT   08048ae4   _fini
    08049d4c  00001307 R_386_JUMP_SLOT   0804872c   _ZSt4endlIcSt11char_tr
    08049d50  00001507 R_386_JUMP_SLOT   0804873c   __gxx_personality_v0
    08049d54  00001607 R_386_JUMP_SLOT   0804874c   _ZNSt8ios_base4InitD1E

In this example, `print` is a function loaded from a shared library (I wrote) at runtime.  `readelf` is able to display information about its location inside the `app` binary.

readelf-like tool for Mac OS X?

How can I set the degree symbol to a `TextView` in Android? 


Content Type	Original Author	Original Content on Stackoverflow
Question	Saajid Ismail	View Question on Stackoverflow
Solution 1 - Sql Server	Ed Guiness	View Answer on Stackoverflow
Solution 2 - Sql Server	Michael Haren	View Answer on Stackoverflow
Solution 3 - Sql Server	Kyle Delaney	View Answer on Stackoverflow
Solution 4 - Sql Server	John Hartsock	View Answer on Stackoverflow
Solution 5 - Sql Server	Baaju	View Answer on Stackoverflow

What does the SQL # symbol mean and how is it used?

Sql Server Problem Overview

Sql Server Solutions

Solution 1 - Sql Server

Solution 2 - Sql Server

Solution 3 - Sql Server

Solution 4 - Sql Server

Solution 5 - Sql Server

Integers caching in Java

Fortran: integer*4 vs integer(4) vs integer(kind=4)

Attributions