The best way to reset a sequence to start back with number 1 is to execute the following:

    ALTER SEQUENCE &lt;tablename&gt;_&lt;id&gt;_seq RESTART WITH 1

So, for example for the `users` table it would be:

    ALTER SEQUENCE users_id_seq RESTART WITH 1

See a better option here: https://stackoverflow.com/a/5272164/5190

Primary keys that autoincrement (i.e., columns with data type `serial primary key`) are associated with a [sequence][1]. You can set the next value for any sequence using the `setval(&lt;seqname&gt;, &lt;next_value&gt;)` function. Note that to actually execute the function by itself you need to use [`SELECT`][2], like this: `SELECT setval(&lt;seqname&gt;, &lt;next_value&gt;)`

The name of the auto created sequences when using serial are `&lt;table&gt;_&lt;column&gt;_seq`

  [1]: http://www.postgresql.org/docs/8.4/interactive//functions-sequence.html
  [2]: https://www.postgresql.org/message-id/20040630135450.GB13891%40wolff.to

TRUNCATE TABLE table_name RESTART IDENTITY;

@bluish actually inserting a new record using an auto-incremented primary key, is just like using a sequence explicitly this way:

    INSERT INTO MyTable (id, col1, ...) VALUES (MySeq.nextval(), val1, ...)

So, if you want the first id to be 1, you should have to set your sequence to 0. But it&#39;s out of bounds, so you must use the ALTER SEQUECE statement.
So, if you have a serial field named number in your table menu, for exemple:

    ALTER SEQUENCE menu_number_seq RESTART

will make the job perfectly.

@ZootHii
TRUNCATE TABLE table_name RESTART IDENTITY CASCADE;

What is the best way to run code on a separate thread? Is it:

    [NSThread detachNewThreadSelector: @selector(doStuff) toTarget:self withObject:NULL];

Or:

    	NSOperationQueue *queue = [NSOperationQueue new];
    NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self
																			selector:@selector(doStuff:)
																			  object:nil;
    [queue addOperation:operation];
    [operation release];
	[queue release];

I&#39;ve been doing the second way but the Wesley Cookbook I&#39;ve been reading uses the first.


iphone ios running in separate thread

How can I add &amp; delete a view from a layout?

Add &amp; delete view from Layout

Is there a way to reset the primary key of a PostgreSQL table to start at 1 again on a populated table?

Right now it&#39;s generating numbers from 1000000 and up. I want it all to reset and start to 1, keeping all my existing data intact.

Reset PostgreSQL primary key to 1

<p>Is there a way to reset the primary key of a PostgreSQL table to start at 1 again on a populated table?</p>
<p>Right now it's generating numbers from 1000000 and up. I want it all to reset and start to 1, keeping all my existing data intact.</p>


Does PostgreSQL support `\b`?

I&#39;m trying `\bAB\b` but it doesn&#39;t match anything, whereas `(\W|^)AB(\W|$)` does. These 2 expressions are essentially the same, aren&#39;t they?

PostgreSQL Regex Word Boundaries?

I want to check type of value in postgres like this:

    SELECT id,
           CASE 
             WHEN val_is_integer THEN (SOME_QUERY)
             WHEN val_isnot_integer THEN (ANOTHER_QUERY)
             ELSE 0
           END
      FROM test;

How to do that?


----------

notes:
the value is varchar type in table, and in that field there is value is numeric and varchar ...

example:

    ID | value
    1 | test
    2 | 10
    3 | 12
    4 | test123

how to check type of value in postgres

I am used to Oracle and to create a dblink in my schema and then access to a remote database like this: `mytable@myremotedb`, is there anyway do to the same with PostgreSQL?

Right now I am using dblink like this: 

    SELECT logindate FROM dblink(&#39;host=dev.toto.com
                                  user=toto
                                  password=isok
                                  dbname=totofamily&#39;, &#39;SELECT logindate FROM loginlog&#39;);

When I execute this command I get the following error:

&gt; HINT: No function matches the given name and argument types. You might need to add explicit type casts.

Does anybody have an idea ? Do we have to &quot;activate&quot; dblinks or do something before using them?

Is there something to do on the remote database we are going to query? Do we have to activate dblink too? I keep having a `could not establish connection`. This is the line is type:

    SELECT dblink_connect_u(&#39;host=x.x.x.x dbname=mydb user=root port=5432&#39;);

IP Address is correct and Postgres is running on the remote server. Any idea?

How to use (install) dblink in PostgreSQL?

Was wondering if someone could assist with some Postgres. I have a table which has a column called `mydate` which is a postgres date type. I want to do something like:

    SELECT * FROM MyTable WHERE mydate &gt; [Today-1year]

I&#39;ve never used Postgres before and I&#39;m sure I just need to know the name of some functions- I&#39;ll gladly look up the reference myself. Can anyone point me in the right direction?

Thanks!

PostgreSQL, checking date relative to &quot;today&quot;

I&#39;m bulk loading data and can re-calculate all trigger modifications much more cheaply after the fact than on a row-by-row basis.

How can I temporarily disable all triggers in PostgreSQL?

How do I temporarily disable triggers in PostgreSQL?

When should I use `KEY`, `PRIMARY KEY`, `UNIQUE KEY` and `INDEX`?

Difference between Key, Primary Key, Unique Key and Index in MySQL

For a number of reasons^, I&#39;d like to use a UUID as a primary key in some of my Django models. If I do so, will I still be able to use outside apps like &quot;contrib.comments&quot;, &quot;django-voting&quot; or &quot;django-tagging&quot; which use generic relations via ContentType?

Using &quot;django-voting&quot; as an example, the Vote model looks like this:

    class Vote(models.Model):
        user         = models.ForeignKey(User)
        content_type = models.ForeignKey(ContentType)
        object_id    = models.PositiveIntegerField()
        object       = generic.GenericForeignKey(&#39;content_type&#39;, &#39;object_id&#39;)
        vote         = models.SmallIntegerField(choices=SCORES)


This app seems to be assuming that the primary key for the model being voted on is an integer. 

The built-in comments app seems to be capable of handling non-integer PKs, though:

    class BaseCommentAbstractModel(models.Model):
        content_type   = models.ForeignKey(ContentType,
                verbose_name=_(&#39;content type&#39;),
                related_name=&quot;content_type_set_for_%(class)s&quot;)
        object_pk      = models.TextField(_(&#39;object ID&#39;))
        content_object = generic.GenericForeignKey(ct_field=&quot;content_type&quot;, fk_field=&quot;object_pk&quot;)

Is this &quot;integer-PK-assumed&quot; problem a common situation for third-party apps which would make using UUIDs a pain? Or, possibly, am I misreading this situation?

Is there a way to use UUIDs as primary keys in Django without causing too much trouble?

&lt;hr/&gt;
^ Some of the reasons: hiding object counts, preventing url &quot;id crawling&quot;, using multiple servers to create non-conflicting objects, ...

Using a UUID as a primary key in Django models (generic relations impact)

As the title, I have an existing table which is already populated with 150000 records. I have added an Id column (which is currently null).

I&#39;m assuming I can run a query to fill this column with incremental numbers, and then set as primary key and turn on auto increment. Is this the correct way to proceed? And if so, how do I fill the initial numbers?



SQL Server add auto increment primary key to existing table

Can anyone tell me what is the difference between a primary key and index key. And when to use which?

What is the difference between a primary key and a index key

Here is a gross oversimplification of an intense setup I am working with. `table_1` and `table_2` both have auto-increment surrogate primary keys as the ID. `info` is a table that contains information about both `table_1` and `table_2`.

    table_1 (id, field)  
    table_2 (id, field, field)
    info ( ???, field)



I am trying to decided if I should make the primary key of `info` a composite of the IDs from `table_1` and `table_2`. If I were to do this, which of these makes most sense?    
*( in this example I am combining ID 11209 with ID 437 )* 

`INT(9)` 11209437   *(i can imagine why this is bad)*  
`VARCHAR (10)`    11209-437   
`DECIMAL (10,4)` 11209.437   

Or something else? 

Would this be fine to use this as the Primary Key on a MYSQL MYISAM DB?


How to properly create composite primary keys - MYSQL

Taking into consideration that there are several git commands that make no sense in a bare repository (because bare repositories don&#39;t use indexes and do not have a working directory), 

    git reset --hard HEAD^ 

is not a solution to uncommit the last change in such a repository.

Searching through the Internet, all I could find related to the topic is [this][1], in which I am presented three ways of doing this:  
1. &quot;update the ref manually (which involves plumbing)&quot;;  
2. &quot;`git push -f` from a non-bare repository&quot;;  
3. &quot;`git branch -f this $that`&quot;.

  [1]: http://kerneltrap.org/mailarchive/git/2007/7/14/251529

Which solution do yo think is more appropriate or what other ways are there to do this? Unfortunately, the documentation I found about git bare repositories is fairly poor.

How can I uncommit the last commit in a git bare repository?

Consider this scenario:

 1. Developer A does a commit: **#n**
 2. Dev. B does commit **#n+1**
 3. Dev. A does commit **#n+2**
 4. and commit **#n+3**

and then discovers that in his commit #n+2 he introduced a defect.

How can dev. A rollback his last 2 commits and continue developing on commit **#n+1**?

Tried `git reset --hard HEAD~2`[*][1], but it&#39;s coming back to dev A&#39;s commit **#n**.

  [1]: http://git-scm.com/docs/git-reset

How to rollback the two previous commits?

`repo status` shows me a lot of un-wanted changes. 

It would be duplicated if I enter every project and use `git reset --hard`. 

Is there a way to reset all the changes using repo, something like `repo reset --hard`?

How to discard changes using repo

I would like to force the auto increment field of a table to some value, I tried with this:

    ALTER TABLE product AUTO_INCREMENT = 1453

AND 

    ALTER SEQUENCE product  RESTART WITH 1453;
    ERROR:  relation &quot;your_sequence_name&quot; does not exist

I&#39;m new to postgres :( 

I have a table `product` with `Id` and `name` field



Reset auto increment counter in postgres

I set par(mfrow =c(1,2)) and now everytime I plot it shows splits it into 2 plots.
How can I reset this to only show one plot.

Thanks so much.



Content Type	Original Author	Original Content on Stackoverflow
Question	David	View Question on Stackoverflow
Solution 1 - Postgresql	Paweł Gościcki	View Answer on Stackoverflow
Solution 2 - Postgresql	Vinko Vrsalovic	View Answer on Stackoverflow
Solution 3 - Postgresql	ZootHii	View Answer on Stackoverflow
Solution 4 - Postgresql	ROQUEFORT François	View Answer on Stackoverflow
Solution 5 - Postgresql	Thangaraj	View Answer on Stackoverflow

Reset PostgreSQL primary key to 1

Postgresql Problem Overview

Postgresql Solutions

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Solution 3 - Postgresql

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Add & delete view from Layout

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