It is not supported to look beyond the current row in a CHECK constraint.

http://www.postgresql.org/docs/9.1/interactive/sql-createtable.html says:

&gt; A check constraint specified as a column constraint should reference
&gt; that column&#39;s value only, while an expression appearing in a table
&gt; constraint can reference multiple columns.
&gt; 
&gt; Currently, CHECK expressions cannot contain subqueries nor refer to
&gt; variables other than columns of the current row.

There are good reasons for this restriction, but if you like to juggle flaming torches while riding a unicycle through heavy traffic, you can subvert the restriction using functions.  The situations in which this will *not* come back to bite you are rare; you would be much safer to enforce the invariant in trigger code instead.

http://www.postgresql.org/docs/9.1/interactive/triggers.html


on x64 Windows 7 I am trying to get hello world MVC 3 website running as 64-bit process (so Environment.Is64BitProcess returns true on a page) using IIS Express 8 latest beta.  

IIS Express 7.5 is 32 bit but IIS Express 8 does support 64 bit (http://learn.iis.net/page.aspx/1266/iis-80-express-beta-readme/).  

Can&#39;t get any 64-bit love.  

Building AnyCpu returns Is64BitProcess false, building x64 gives &quot;An attempt was made to load a program with an incorrect format. &quot; as if it was trying to run as 32-bit process. 

 Experiments w/ renaming folders etc. suggest that &quot;**C:\Program Files (x86)\IIS Express**&quot; is only thing that is getting used, and &quot;**C:\Program Files\IIS Express&quot;** is being ignored by VS.  

How can I get VS to use the x64 IIS Express host?


Can&#39;t get IIS Express 8 beta to run website as 64-bit process

Update: Already fixed, it seems that one of VirtualHosts configurations files was wrong in sites-enabled.

I have Ubuntu 11.10

When I run the command to start apache2:

    sudo /etc/init.d/apache2 start

I get the following error message:

&gt;  Starting web server apache2                                        
&gt; apache2: Could not reliably determine the server&#39;s fully qualified
&gt; domain name, using 127.0.1.1 for ServerName (98)Address already in
&gt; use: make_sock: could not bind to address 0.0.0.0:80 no listening
&gt; sockets available, shutting down Unable to open logs Action &#39;start&#39;
&gt; failed.

I run this command in order to get the process that is using the port 80:

    sudo netstat -ltnp | grep &#39;:80&#39;

Which returns this output:

    tcp6       0      0 :::80                   :::*                    LISTEN      1176/

To know which process is I run this command:

    ps -wlp1176

That returns: 

    F S   UID   PID  PPID  C PRI  NI ADDR SZ WCHAN  TTY          TIME CMD
    5 D    33  1176     1  0  80   0 -     0 exit   ?        00:00:00 apache2

But if I try to kill the process: 

    sudo kill -9 1176

It doesn&#39;t kill it, if I run again the netstat command still appears listening and apache start fails.

Any suggestions?

Starting apache fails (could not bind to address 0.0.0.0:80)

Can I make SQL sub queries in Check constraint ?

I&#39;ve a `post` table with columns `id, owner`&lt;br /&gt;
I&#39;ve another table `action` with columns `user_id, post_id`&lt;br /&gt;
Table `user` with columns `id`

`post_id -&gt; post.id` and `user_id -&gt; user.id` also `post.owner -&gt; user.id`

Now I want to constraint `post(post_id).id != user_id` on table `action`

How is that possible ?

SQL Sub queries in check constraint

Can I make SQL sub queries in Check constraint ?
I've a <code>post</code> table with columns <code>id, owner</code> 
I've another table <code>action</code> with columns <code>user_id, post_id</code> 
Table <code>user</code> with columns <code>id</code>
<code>post_id -> post.id</code> and <code>user_id -> user.id</code> also <code>post.owner -> user.id</code>
Now I want to constraint <code>post(post_id).id != user_id</code> on table <code>action</code>
How is that possible ?

I have a table that has 20 integer columns and 1 text column named &#39;foo&#39;

If I run query:

    SELECT * from table_name where foo is NULL

I get error:

    ERROR:  column &quot;foo&quot; does not exist

I have checked myself that his column indeed exists. If I do something like:

    SELECT * from table_name where count is NULL

The resulting output shows &#39;foo&#39; as one of the columns....
I am guessing I have to do something special in the query because foo is a text column...

Thanks for the help (POSTGRESQL 8.3)

PostgreSQL column &#39;foo&#39; does not exist

How can I discard/round the `millisecond` part, better if the `second` part is also removed from a `timestamp` w/o `timezone` ?

Discard millisecond part from timestamp

I am trying to loop through an integer array (`integer[]`) in a plpgsql function. Something like this:

    declare
        a integer[] = array[1,2,3];
        i bigint;
    begin
        for i in a
    loop 
        raise notice &quot;% &quot;,i;
    end loop;
    return true;
    end

In my actual use case the integer array `a` is passed as parameter to the function. I get this error:

&gt;     ERROR:  syntax error at or near &quot;$1&quot;
&gt;     LINE 1:   $1

How to loop through the array properly?

Iterating over integer[] in PL/pgSQL

I&#39;m a little new to postgres. I want to take a value (which is an integer) in a field in a postgres table and increment it by one. For example if the table &#39;totals&#39; had 2 columns, &#39;name&#39; and &#39;total&#39;, and Bill had a total of 203, what would be the SQL statement I&#39;d use in order to move Bill&#39;s total to 204?

Increment a value in Postgres

I am beginner to PostgreSQL.

I want to connect to another database from the query editor of Postgres - like the `USE` command of MySQL or MS SQL Server. 
 
I found `\c databasename` by searching the Internet, but its runs only on [psql][1]. When I try it from the PostgreSQL query editor I get a syntax error.

I have to change the database by pgscripting. Does anyone know how to do it?


  [1]: http://www.postgresql.org/docs/current/interactive/app-psql.html

&quot;use database_name&quot; command in PostgreSQL

If I am using the following SQL command in SQL Server 2008 to update a table with a foreign key constraint:

    ALTER TABLE Employees
    ADD FOREIGN KEY (UserID)
    REFERENCES ActiveDirectories(id)

**`UserID`** being my FK column in the `Employees` table. I&#39;m trying to reference the **`UserID`** in my `ActiveDirectories` table. I receive this error:

&gt; Foreign key &#39;UserID&#39; references invalid column &#39;UserID&#39; in referencing
&gt; table &#39;Employees&#39;.

SQL Add foreign key to existing column

I&#39;m having a little difficulty getting my head around relationships in Django models. 

Could someone explain what the difference is between a OneToOne, ManyToMany and ForeignKey?

Whats the difference between a OneToOne, ManyToMany, and a ForeignKey Field in Django?

I have 2 tables as you will see in my posgresql code below. The first table students has 2 columns, one for student_name and the other student_id which is the primary key.
  In my second table called tests, this has 4 columns, one for  subject_id, one for the subject_name, then one for a student with the higest score in a subject which is highestStudent_id. am trying to make highestStudent_id refer to student_id in my students table. This is the code i have below , am not sure if the syntax is correct:

    CREATE TABLE students ( student_id SERIAL PRIMARY KEY,
					 player_name TEXT);

    CREATE TABLE tests ( subject_id SERIAL,
                       subject_name,
					   highestStudent_id SERIAL REFERENCES students);

is the syntax `highestStudent_id SERIAL REFERENCES students` correct? because i have seen another one like `highestStudent_id  REFERENCES students(student_id))`

What would be the correct way of creating the foreign key in postgresql please?

postgresql foreign key syntax

I want to pass a table name as a parameter in a Postgres function. I tried this code:

    CREATE OR REPLACE FUNCTION some_f(param character varying) RETURNS integer 
    AS $$
        BEGIN
    	IF EXISTS (select * from quote_ident($1) where quote_ident($1).id=1) THEN
    	 return 1;
    	END IF;
        return 0;
        END;
    $$ LANGUAGE plpgsql;
    
    select some_f(&#39;table_name&#39;);

And I got this:

    ERROR:  syntax error at or near &quot;.&quot;
    LINE 4: ...elect * from quote_ident($1) where quote_ident($1).id=1)...
                                                                 ^
    
    ********** Error **********
    
    ERROR: syntax error at or near &quot;.&quot;

And here is the error I got when changed to this `select * from quote_ident($1) tab where tab.id=1`:

    ERROR:  column tab.id does not exist
    LINE 1: ...T EXISTS (select * from quote_ident($1) tab where tab.id...

Probably, `quote_ident($1)` works, because without the `where quote_ident($1).id=1` part I get `1`, which means something is selected. Why may the first `quote_ident($1)` work and the second one not at the same time? And how could this be solved?

Table name as a PostgreSQL function parameter

I have a URLs table. They contain 

(id int primary key,
 url character varying unique, 
content character varying, 
last analyzed date). 

I want to create trigger or something(rule may be), so each time i make insert from my java program, it updates some single row if row with such URL exists. Else it should perform an Insert.

Please, can you provide a complete code in Postgresql. Thanks.

Postgresql, update if row with some unique value exists, else insert

How can I do such query in Postgres?

    IF (select count(*) from orders) &gt; 0
    THEN
      DELETE from orders
    ELSE 
      INSERT INTO orders values (1,2,3);

PostgreSQL IF statement

I&#39;m writing a function in PL/pgSQL, and I&#39;m looking for the simplest way to check if a row exists.  
Right now I&#39;m SELECTing an `integer` into a `boolean`, which doesn&#39;t really work. I&#39;m not experienced with PL/pgSQL enough yet to know the best way of doing this.

Here&#39;s part of my function:

    DECLARE person_exists boolean;
    BEGIN

    person_exists := FALSE;

    SELECT &quot;person_id&quot; INTO person_exists
      FROM &quot;people&quot; p
    WHERE p.person_id = my_person_id
    LIMIT 1;

    IF person_exists THEN
      -- Do something
    END IF;

    END; $$ LANGUAGE plpgsql;

*Update* - I&#39;m doing something like this for now:

    DECLARE person_exists integer;
    BEGIN

    person_exists := 0;

    SELECT count(&quot;person_id&quot;) INTO person_exists
      FROM &quot;people&quot; p
    WHERE p.person_id = my_person_id
    LIMIT 1;

    IF person_exists &lt; 1 THEN
      -- Do something
    END IF;

Content Type	Original Author	Original Content on Stackoverflow
Question	Dipro Sen	View Question on Stackoverflow
Solution 1 - Postgresql	kgrittn	View Answer on Stackoverflow

SQL Sub queries in check constraint

Postgresql Problem Overview

Postgresql Solutions

Solution 1 - Postgresql

Starting apache fails (could not bind to address 0.0.0.0:80)

Can't get IIS Express 8 beta to run website as 64-bit process

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