From the [fine manual][1]:

    ALTER TABLE mytable ALTER COLUMN mycolumn DROP NOT NULL;

There&#39;s no need to specify the type when you&#39;re just changing the nullability.


  [1]: http://www.postgresql.org/docs/current/interactive/sql-altertable.html

Zero is always zero, so it doesn&#39;t matter. But in a recent discussion with a friend he said that octal literals are almost unused today.&lt;sup&gt;†&lt;/sup&gt; Then it dawned upon me that actually almost *all* integer literals in my code *are* octal, namely `0`.

Is `0` an octal literal according to the C++ grammar? What does the standard say?

&lt;sub&gt;&lt;sup&gt;†&lt;/sup&gt; The only real use I&#39;m aware of is for unix file permissions.&lt;/sub&gt;

Is 0 a decimal literal or an octal literal?

Can anyone explain or suggest a tutorial to dynamically create a [`ListView`][1] in android? 

Here are my requirements:

 - I should be able to dynamically add new elements by pressing a button.
 - Should be simple enough to understand (possibly without any performance improvements or [convertView][2], for instance)

I know there are quite a few questions on this topic, but I couldn&#39;t find any that answer my question.


  [1]: https://developer.android.com/reference/android/widget/ListView
  [2]: https://developer.android.com/reference/android/widget/Adapter

How do you dynamically add elements to a ListView on Android?

How can I accomplish this using Postgres? I&#39;ve tried the code below but it doesn&#39;t work:

    ALTER TABLE mytable ALTER COLUMN mycolumn BIGINT NULL; 



How to change a PG column to NULLABLE TRUE?

How can I accomplish this using Postgres? I've tried the code below but it doesn't work:
<pre><code class="hljs language-sql">ALTER TABLE mytable ALTER COLUMN mycolumn BIGINT NULL; 
</code></pre>

I am getting the result in SQL Server as 

    SELECT StudentId FROM Student WHERE condition = xyz

I am getting the output like

&lt;pre&gt;
StudentId
1236

7656

8990
........
&lt;/pre&gt;
The output parameter of the stored procedure is `@studentId` string and I want the return statement as 

    1236, 7656, 8990.

How can I convert the output in the single string? 

I am returning single column [ie. StudentId]

Convert SQL Server result set into string

I have the following code in one of my Sql (2008) Stored Procs which executes perfectly fine:

        CREATE PROCEDURE [dbo].[Item_AddItem]
            @CustomerId uniqueidentifier,
            @Description nvarchar(100),
            @Type int,
            @Username nvarchar(100),
        AS
        BEGIN
        
            DECLARE @TopRelatedItemId uniqueidentifier;
            SET @TopRelatedItemId = 
            (
               SELECT top(1) RelatedItemId 
               FROM RelatedItems 
               WHERE CustomerId = @CustomerId
            ) 
        
            DECLARE @TempItem TABLE
            (
                ItemId uniqueidentifier,
                CustomerId uniqueidentifier,
                Description nvarchar(100),
                Type int,
                Username nvarchar(100),
                TimeStamp datetime
            );
        
            INSERT INTO Item
            OUTPUT INSERTED.* INTO @TempItem
            SELECT NEWID(), @CustomerId, @Description, @Type, @Username, GETDATE()
        
            SELECT
                ItemId,
                CustomerId,
                @TopRelatedItemId,
                Description,
                Type,
                Username,
                TimeStamp
            FROM
                @TempItem
    END
    GO

 
    

**So the question for you guys is is there a possibility to do something along the lines of:**

    DECLARE @TempCustomer TABLE
    (
       CustomerId uniqueidentifier,
       FirstName nvarchar(100),
       LastName nvarchar(100),
       Email nvarchar(100)
    );
    SELECT 
        CustomerId, 
        FirstName, 
        LastName, 
        Email 
    INTO 
        @TempCustomer 
    FROM 
        Customer
    WHERE 
        CustomerId = @CustomerId

So that I could reuse this data from memory in other following statements? SQL Server throws a fit with the above statement, however i don&#39;t want to have to create separate variables and initialize each one of them via a separate SELECT statement against the same table.... UGH!!!

Any suggestions on how to achieve something along the lines without multiple queries against the same table?

SQL Server SELECT INTO @variable?

I am wondering if this is possible at all. I want to update column x if a condition is true, otherwise column y would be updated

    UPDATE table SET
         (CASE (CONDITION) WHEN TRUE THEN columnx
                           ELSE columny
          END)
    = 25
I have searched all over, tried out some things and am unable to find a solution. I think it&#39;s not possible, but I thought I would ask here and see if anyone has done it before. Thanks in advance.

T-SQL: Using a CASE in an UPDATE statement to update certain columns depending on a condition

So I&#39;m writing a stored procedure in MS SQL Server 2008. It&#39;s a really long query and I have to write it dynamically, so I create a variable called `@Query` and make it of type `NVARCHAR(MAX)`. Now, I have been *told* that in modern versions of SQL Server, `NVARCHAR(MAX)` can hold a ridiculous amount of data, way more than the original 4000 character maximum. However, `@Query` is still getting truncated to 4000 characters when I try to print it out.

    DECLARE @Query NVARCHAR(max);
    SET @Query = &#39;SELECT...&#39; -- some of the query gets set here
    SET @Query = @Query + &#39;...&#39; -- more query gets added on, etc.
    
    -- later on...
    PRINT LEN(@Query) -- Prints out 4273, which is correct as far as I can tell
    PRINT @Query      -- Truncates value to 4000 characters
    EXEC sp_executesql @Query -- totally crashes due to malformed (truncated) query

Am I doing something incorrectly, or am I completely wrong about how `NVARCHAR(MAX)` works?

nvarchar(max) still being truncated

Naming conventions are important, and primary key and foreign key have commonly used and obvious conventions (`PK_Table` and `FK_Table_ReferencedTable`, respectively).  The `IX_Table_Column` naming for indexes is also fairly standard.

What about the UNIQUE constraint?  Is there a commonly accepted naming convention for this constraint?  I&#39;ve seen `UK_TableName_Column`, `UQ_TableName_Column`, and someone recommending `AX_TableName_Column` - I don&#39;t know where that comes from.

I&#39;ve typically used `UQ` but I don&#39;t particularly like it, and I do not enjoy having to defend my choice of using it against a `UK` advocate.

I would simply like to see if there is a consensus on the most prevalent naming, or a good reasoning as to why one makes more sense than the others.



Naming convention for unique constraint

How can I find out which version of PostGIS I have?

Get PostGIS version

What&#39;s the difference between the `text` data type and the `character varying` (`varchar`) data types?

According to [the documentation][1]

&gt; If character varying is used without length specifier, the type accepts strings of any size. The latter is a PostgreSQL extension.

and

&gt; In addition, PostgreSQL provides the text type, which stores strings of any length. Although the type text is not in the SQL standard, several other SQL database management systems have it as well.

So what&#39;s the difference?

  [1]: http://www.postgresql.org/docs/8.0/interactive/datatype-character.html

Difference between text and varchar (character varying)

I&#39;m [trying to import some data][1] into my database. So I&#39;ve created a temporary table,

    create temporary table tmp(pc varchar(10), lat decimal(18,12), lon decimal(18,12), city varchar(100), prov varchar(2));

And now I&#39;m trying to import [the data][2],

     copy tmp from &#39;/home/mark/Desktop/Canada.csv&#39; delimiter &#39;,&#39; csv

But then I get the error,

    ERROR:  invalid byte sequence for encoding &quot;UTF8&quot;: 0xc92c

How do I fix that? Do I need to change the encoding of my entire database (if so, how?) or can I change just the encoding of my `tmp` table? Or should I attempt to change the encoding of the file?


  [1]: https://stackoverflow.com/questions/4866753/how-to-import-these-postal-codes-into-a-normalized-table
  [2]: http://geocoder.ca/?freedata=1


invalid byte sequence for encoding &quot;UTF8&quot;

I have a simple list of ~25 words. I have a varchar field in PostgreSQL, let&#39;s say that list is `[&#39;foo&#39;, &#39;bar&#39;, &#39;baz&#39;]`. I want to find any row in my table that has any of those words. This will work, but I&#39;d like something more elegant.

    select *
    from table
    where (lower(value) like &#39;%foo%&#39; or lower(value) like &#39;%bar%&#39; or lower(value) like &#39;%baz%&#39;)

PostgreSQL wildcard LIKE for any of a list of words

I currently have the the following query:

    select regexp_matches(name, &#39;foo&#39;) from table;

How can I rewrite this so that the regex is in the where like the following (not working):

    select * from table where regexp_matches(name, &#39;foo&#39;);

Current error message is:
ERROR: argument of WHERE must be type boolean, not type text[]
SQL state: 42804
Character: 29


Using regex in WHERE in Postgres

may be it is a simple question but I&#39;m try all of conversion method! and it still has error!
would you help me?

decimal? (nullable decimal) to decimal

How can I convert decimal? to decimal

Query to check whether a column is nullable (null values are allowed in the column or not).
It should preferably return yes/no or 1/0 or true/false.

Query to check whether a column is nullable

I examine the properties of an object via reflection and continue processing the data type of each property. Here is my (reduced) source:

    private void ExamineObject(object o)
    {
      Type type = default(Type);
      Type propertyType = default(Type);
      PropertyInfo[] propertyInfo = null;

      type = o.GetType();

      propertyInfo = type.GetProperties(BindingFlags.GetProperty |
                                        BindingFlags.Public |
                                        BindingFlags.NonPublic |
                                        BindingFlags.Instance);
      // Loop over all properties
      for (int propertyInfoIndex = 0; propertyInfoIndex &lt;= propertyInfo.Length - 1; propertyInfoIndex++)
      {
        propertyType = propertyInfo[propertyInfoIndex].PropertyType;
      }
    }

My problem is, that I newly need to handle nullable properties, but I have no clue how to get the type of a nullable property.

Find type of nullable properties via reflection

In VB.NET, is there a way to set a `DateTime` variable to &quot;not set&quot;? And why is it possible to set a `DateTime` to `Nothing`, but *not* possible to check if it is `Nothing`? For example:

    Dim d As DateTime = Nothing
    Dim boolNotSet As Boolean = d Is Nothing 

The second statement throws this error:

&lt;!-- language: none --&gt;

    &#39;Is&#39; operator does not accept operands of type &#39;Date&#39;. Operands must be reference or
    nullable types.







Why can&#39;t I check if a &#39;DateTime&#39; is &#39;Nothing&#39;?

How do I convert a nullable `int` to an `int`? Suppose I have 2 type of int as below:

    int? v1;  
    int v2; 

I want to assign `v1`&#39;s value to `v2`. `v2 = v1;` will cause an error. How do I convert `v1` to `v2`?

Content Type	Original Author	Original Content on Stackoverflow
Question	mateusmaso	View Question on Stackoverflow
Solution 1 - Sql	mu is too short	View Answer on Stackoverflow

How to change a PG column to NULLABLE TRUE?

Sql Problem Overview

Sql Solutions

Solution 1 - Sql

How do you dynamically add elements to a ListView on Android?

Is 0 a decimal literal or an octal literal?

Attributions