Bug #869: varchar 's comparision

On Thu, 9 Jan 2003 pgsql-bugs@postgresql.org wrote:

trainee (trainee12@yeah.net) reports a bug with a severity of 2
The lower the number the more severe it is.

Short Description
varchar 's comparision

Long Description
SERVER: PGSQL 7.31 + MANDRAKE LINUX 8.1
CLIENT: VISIVAL FOXPRO 7.0 + PGSQLODBC 7.02

TABLE : MYTABLE
M_ID VARCHAR(10) M_DESC VARCHAR(10)
-----------------------------------------------------------
ABC HELLO

I create a romate view in vfp, when I modify "m_desc" from "HELLO"
TO "GOOD" ,and update table, vfp trigger a error "UPDATE CONFLICT".

In odbc-log: (THIS SQL SYNTAX IS GENERATED BY VFP )
---------------------------------------------------------------
UPDATE MYTABLE SET M_DESC='GOOD' WHERE M_ID='ABC ' AND M_DESC='HELLO '

varchar() considers trailing spaces as significant, so 'ABC'!='ABC '
If it's going to generate values with trailing spaces, you might want to
use char() instead.

pgsql-bugs@postgresql.org writes:

M_ID VARCHAR(10) M_DESC VARCHAR(10)
-----------------------------------------------------------
ABC HELLO

UPDATE MYTABLE SET M_DESC='GOOD' WHERE M_ID='ABC ' AND M_DESC='HELLO '

UPDATE 0 RECORDS

My guess is that the stored values do not have trailing spaces.
Trailing spaces are significant data in varchar fields.

regards, tom lane