    ALTER TABLE users
      ADD COLUMN &quot;priv_user&quot; BOOLEAN DEFAULT FALSE;

you can also directly specify NOT NULL

    ALTER TABLE users
      ADD COLUMN &quot;priv_user&quot; BOOLEAN NOT NULL DEFAULT FALSE;

**UPDATE**: following is only true for versions before postgresql 11.

As Craig mentioned on filled tables it is more efficient to split it into steps:

    ALTER TABLE users ADD COLUMN priv_user BOOLEAN;
    UPDATE users SET priv_user = &#39;f&#39;;
    ALTER TABLE users ALTER COLUMN priv_user SET NOT NULL;
    ALTER TABLE users ALTER COLUMN priv_user SET DEFAULT FALSE;


If you want an actual boolean column:

    ALTER TABLE users ADD &quot;priv_user&quot; boolean DEFAULT false;

Just for future reference, if you *already* have a boolean column and you just want to add a default do:

    ALTER TABLE users
      ALTER COLUMN priv_user SET DEFAULT false;

If you are using postgresql then you have to use column type BOOLEAN in lower case as boolean.

ALTER TABLE users ADD &quot;priv_user&quot; boolean DEFAULT false; 


In psql alter column query syntax like this 

    Alter table users add column priv_user boolean default false ;

boolean value **(true-false)** save in DB like **(t-f)** value .


I&#39;m looking for a way to make a virtualenv which will contain just some libraries (which I chose) of the base python installation.

To be more concrete, I&#39;m trying to import my matplotlib to virtualenv during the creation of virtualenv. It can&#39;t be installed efficiently with pip or easy_install since it misses some fortran compiler libs. The way I did it until now was to manually copy from:

    /usr/lib/python2.7/dist-packages/ to virtualenv_name/lib/python2.7/dist-packages/

However this prevents the manully imported links to be registerd by yolk (which prints all currently available libs in virtualenv).

So, is there a way to do a selective variant of the

    virtualenv --system-site-packages


Make virtualenv inherit specific packages from your global site-packages

Example:

&lt;!-- language: none --&gt;

    www.site.com/index.php#hello

Using jQuery, I want to put the value `hello` in a variable:

    var type = …

How do I get the fragment identifier (value after hash #) from a URL?

Is this proper postgresql syntax to add a column to a table with a default value of `false`


    ALTER TABLE users
    ADD &quot;priv_user&quot; BIT
    ALTER priv_user SET DEFAULT &#39;0&#39;

Thanks!

postgresql - add boolean column to table set default

Is this proper postgresql syntax to add a column to a table with a default value of <code>false</code>
<pre><code class="hljs language-sql">ALTER TABLE users
ADD "priv_user" BIT
ALTER priv_user SET DEFAULT '0'
</code></pre>
Thanks!

How to select row number in postgres.

I tried this:

    select
        row_number() over (ORDER BY cgcode_odc_mapping_id)as rownum,
        cgcode_odc_mapping_id
      from access_odc.access_odc_mapping_tb
      order by cgcode_odc_mapping_id

and got this error:

&lt;pre&gt;
ERROR: syntax error at or near &quot;over&quot;
LINE 1: select row_number() over (ORDER BY cgcode_odc_mapping_id)as
&lt;/pre&gt;

I have checked these pages : https://stackoverflow.com/questions/3397121/how-to-show-row-numbers-in-postgresql-query


---

  This is my query:

     select row_number() over (ORDER BY cgcode_odc_mapping_id)as rownum,cgcode_odc_mapping_id from access_odc.access_odc_mapping_tb order by cgcode_odc_mapping_id 

this is the error: 

ERROR: syntax error at or near &quot;over&quot; LINE 1: select row_number() over (ORDER BY cgcode_odc_mapping_id)as

Select Row number in postgres

Going crazy trying to set a variable in a query of type:

    SET @idcamposexcluidos=&#39;817,803,495&#39;;

so i can then use it on a 

    WHERE id_campo not in (@idcamposexcluidos)

I&#39;ve tried defining the variable in different formats with no luck and don&#39;t seem to find an specific example for the above:

    SET @idcamposexcluidos=&#39;(817,803,495)&#39;;
    ...
    WHERE id_campo not in @idcamposexcluidos


    SET @idcamposexcluidos=817,803,495;

with no success. It either returns an error or ignores the values.

MySQL variable format for a &quot;NOT IN&quot; list of values

I want to execute a stored procedure in SQL Server and assign the output to a variable (it returns a single value) ?

How to return the output of stored procedure into a variable in sql server

Trying to create this example table structure in Postgres 9.1:

```pgsql
CREATE TABLE foo (
	name        VARCHAR(256) PRIMARY KEY
);

CREATE TABLE bar (
	pkey 	    SERIAL PRIMARY KEY,
	foo_fk      VARCHAR(256) NOT NULL REFERENCES foo(name),	
	name        VARCHAR(256) NOT NULL, 
	UNIQUE (foo_fk,name)
);

CREATE TABLE baz(	
	pkey 	    SERIAL PRIMARY KEY,
	bar_fk      VARCHAR(256) NOT NULL REFERENCES bar(name),
	name        VARCHAR(256)
);
```
    
Running the above code produces an error, which does not make sense to me:

&gt;     NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index &quot;foo_pkey&quot; for table &quot;foo&quot;
&gt;     NOTICE:  CREATE TABLE will create implicit sequence &quot;bar_pkey_seq&quot; for serial column &quot;bar.pkey&quot;
&gt;     NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index &quot;bar_pkey&quot; for table &quot;bar&quot;
&gt;     NOTICE:  CREATE TABLE / UNIQUE will create implicit index &quot;bar_foo_fk_name_key&quot; for table &quot;bar&quot;
&gt;     NOTICE:  CREATE TABLE will create implicit sequence &quot;baz_pkey_seq&quot; for serial column &quot;baz.pkey&quot;
&gt;     NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index &quot;baz_pkey&quot; for table &quot;baz&quot;
&gt;     ERROR:  there is no unique constraint matching given keys for referenced table &quot;bar&quot;
    
    
    ********** Error **********
    
    ERROR: there is no unique constraint matching given keys for referenced table &quot;bar&quot;
    SQL state: 42830

Can anyone explain why this error arises?

ERROR: there is no unique constraint matching given keys for referenced table &quot;bar&quot;

I have been trying to find some info on how to select a non-aggregate column that is not contained in the Group By statement in SQL, but nothing I&#39;ve found so far seems to answer my question. I have a table with three columns that I want from it. One is a create date, one is a ID that groups the records by a particular Claim ID, and the final is the PK. I want to find the record that has the max creation date in each group of claim IDs. I am selecting the MAX(creation date), and Claim ID (cpe.fmgcms_cpeclaimid), and grouping by the Claim ID. But I need the PK from these records (cpe.fmgcms_claimid), and if I try to add it to my select clause, I get an error. And I can&#39;t add it to my group by clause because then it will throw off my intended grouping. Does anyone know any workarounds for this? Here is a sample of my code:

    Select MAX(cpe.createdon) As MaxDate, cpe.fmgcms_cpeclaimid 
    from Filteredfmgcms_claimpaymentestimate cpe
    where cpe.createdon &lt; &#39;reportstartdate&#39;
    group by cpe.fmgcms_cpeclaimid

This is the result I&#39;d like to get:

    Select MAX(cpe.createdon) As MaxDate, cpe.fmgcms_cpeclaimid, cpe.fmgcms_claimid 
    from Filteredfmgcms_claimpaymentestimate cpe
    where cpe.createdon &lt; &#39;reportstartdate&#39;
    group by cpe.fmgcms_cpeclaimid

Select a Column in SQL not in Group By

I am using SEAM 2/Hibernate along with PostgreSQL 9 database. I have the following table

    Active Band
    ===========
    active_band_id serial
    active_band_user text
    active_band_date timestamp
    active_band_process integer

I would like to add a constraint that ensures each new entry has a unique combination of active_band_user and active_band_date.

There could potentially be many attempted inserts per second so I need this to be as efficient as possible, is there a SEAM / hibernate annotation I can use in the entity mapping?

Thanks in advance

Unique Constraint Over Multiple Columns

I&#39;m using http://postgresapp.com. In the menubar it gives the error &quot; Could not start on port 5432.&quot; Similarly if I try to start the server from the terminal, I get:

    psql: could not connect to server: No such file or directory
    	Is the server running locally and accepting
    	connections on Unix domain socket &quot;/tmp/.s.PGSQL.5432&quot;?

I also ran `pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start`
and got the output `server starting` but still get the same errors when connecting to psql.

Postgres.app Could not start on port 5432

I have my measurement data stored into the following structure:

    CREATE TABLE measurements(
    measured_at TIMESTAMPTZ,
    val INTEGER
    );

I **already** know that using 

(a) `date_trunc(&#39;hour&#39;,measured_at)` 

AND

(b) `generate_series`

I would be able to aggregate my data by: 

    microseconds,
    milliseconds
    .
    .
    .

But is it possible to aggregate the data by 5 minutes or let&#39;s say an arbitrary amount of seconds? Is it possible to aggregate measured data by an arbitrary multiple of seconds?

I need the data aggregated by different time resolutions to feed them into a FFT or an AR-Model in order to see possible seasonalities.



Content Type	Original Author	Original Content on Stackoverflow
Question	1252748	View Question on Stackoverflow
Solution 1 - Sql	Eelke	View Answer on Stackoverflow
Solution 2 - Sql	rfusca	View Answer on Stackoverflow
Solution 3 - Sql	LondonRob	View Answer on Stackoverflow
Solution 4 - Sql	Faisal Chohan	View Answer on Stackoverflow
Solution 5 - Sql	Meet Patel	View Answer on Stackoverflow

postgresql - add boolean column to table set default

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How do I get the fragment identifier (value after hash #) from a URL?

Make virtualenv inherit specific packages from your global site-packages

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