Re: crosstab function

Ron <ronljohnsonjr@xxxxxxxxx> · Tue, 26 Feb 2019 22:42:32 -0600



    On 2/26/19 7:51 PM, Martin Mueller wrote:

    
        I run
            Postgres 10.5.  I understand that there is something called
            tablefunc and it includes a crosstab function. On Stack
            Overflow I learn that you import this function. But from
            where and how?  The Postgres documentation is quite clear
            and intelligible to a retired English professor like me, but
            there is nothing in the Postgres documentation about how to
            do the import, and a search for ‘import modules’ yields
            nothing.
            
         
        I tried to
            emulate a Stack overflow query that does what I want to do,
            but got an error message saying that the crosstab function
            doesn’t exist. I tried
            
         
        CREATE EXTENSION
          IF
          NOT
          EXISTS tablefunc;
         
        but it did
            nothing. It doesn’t seem to work  as import statements in
            Python do
      
    
    Extensions are short bits of sql that create functions for you, and
    point to "shared object" executable files.  Quite literally, it's
    extending postgres.

    
    Thus, the actual executable file needs to be somewhere on the
    computer's hard drive (specifically, where Postgres expects it to be
    for your OS).

    
    In the Linux world, for example, there's typically a package you
    install named something like
    postgresql96-contrib-9.6.9-blahblah.rpm.  You'd install that using
    the OS' package manager, restart postgres and then CREATE EXTENSION
    should work.

    
    You'll have to determine whether PostgreApp comes with "contribs". 
    If not, you'll have to use another source for Pg, like MacPorts.

    
    -- 

      Angular momentum makes the world go 'round.