Thread

1. problem with arrays

   Massimo Dal Zotto <dz@cs.unitn.it> — 1999-01-06T16:39:09Z

   Hi,
   
   I'm trying to convert some tables from version 6.2 to 6.4.2 but I have
   problems with arrays. The old table definition was:
   
     create table a (
   	x int4,
   	y char8,
   	z char8[]
     );
   
   Now, because the char8 datatype has been removed from postgres, I suppose
   I should use char(8) or varchar(8):
   
     create table a (
   	x int4,
   	y char(8),
   	z char(8)[]
     );
   
   or
   
     create table a (
   	x int4,
   	y varchar(8),
   	z varchar(8)[]
     );
   
   but when I try the above definitions I get the following errors:
   
   dz=> create table a (
   dz-> 	x int4,
   dz-> 	y char(8),
   dz-> 	z char(8)[]
   dz-> );
   ERROR:  type name lookup of _bpchar failed
   
   dz=> create table a (
   dz-> 	x int4,
   dz-> 	y varchar(8),
   dz-> 	z varchar(8)[]
   dz-> );
   ERROR:  type name lookup of _varchar failed
   
   Also trying to define the _varchar or _bpchar types fails, so it seems that
   the conversion from 6.2 to 6.4 is not possible for many data types.
   Any suggestion?
   
   -- 
   Massimo Dal Zotto
   
   +----------------------------------------------------------------------+
   |  Massimo Dal Zotto               email: dz@cs.unitn.it               |
   |  Via Marconi, 141                phone: ++39-0461534251              |
   |  38057 Pergine Valsugana (TN)      www: http://www.cs.unitn.it/~dz/  |
   |  Italy                             pgp: finger dz@tango.cs.unitn.it  |
   +----------------------------------------------------------------------+
   
   

2. Re: [HACKERS] problem with arrays

   Thomas Lockhart <lockhart@alumni.caltech.edu> — 1999-01-07T02:46:44Z

   > Also trying to define the _varchar or _bpchar types fails, so it seems 
   > that the conversion from 6.2 to 6.4 is not possible for many data 
   > types. Any suggestion?
   
   That sucks. afaik the only data types affected are the fixed-maximum
   with variable-length strings. There was a comment in gram.y from Jolly
   regarding the possibility for allowing bpchar and varchar into arrays,
   though she explicitly disallowed it. I had thought that this code is
   still in effect.
   
   I'm not certain how much you have looked at this, but the leading
   underscore is a Postgres convention for array data types. The trick to
   allowing bpchar, varchar, and perhaps numeric types into arrays is
   passing along the element dimensions. I haven't looked at whether that
   already happens.
   
   In the meantime, you can try using the text type instead. I know it
   doesn't have an 8-byte maximum length, but it is allowed in arrays...
   
                         - Tom