[fpc-devel] TField.AsString and Databases with UTF-8 charset

[Graeme Geldenhuys]

Michael Van Canneyt wrote:
> 
> You may never trim these fields; The database contains always the
> declared number of characters: the value is trimmed with a space till
> the number of declared characters is reached. TField.AsString returns
> what is in the database, which seems to be 8 characters in your case.

Yes Firebird returns 8 characters for a Char(2) database field. Firebird 
is very happy with inserting "en", but when read it back with FPC, it 
returns "en      "

If I run a select query using the FlameRobin database tool against that 
exact same database and table, FlameRobin returns "en". FPC's SqlDB doesn't.

==============[  database DDL  ]====================
CREATE DOMAIN D_OID AS Char(36)
  COLLATE UTF8;

CREATE TABLE COUNTRY(
   OID D_OID NOT NULL,
   ID Char(2) NOT NULL,
   NAME Varchar(50) NOT NULL,
   CONSTRAINT PK_COUNTRY PRIMARY KEY (OID)
);
=================[  end  ]====================

When I ask FlameRobin to export the Country table data as INSERT 
statements, it does it correctly with the correct spacing as shown below.

==========================
INSERT INTO COUNTRY (OID, ID, NAME) VALUES ('ZA 
          ', 'ZA', 'South Africa');
==========================

36 characters for the OID field and 2 characters for the ID field. Just 
like I defined it in the DDL.

So why does FlameRobin handle Char() fields as I expected, but FPC's 
SqlDB does something different. So who is right and who is wrong?


> No, because it is fundamentally wrong.

I did not mean with a simple Trim() function. I meant being more precise 
and still return the correct amount of characters as defined in the DDL. 
Or maybe do some UTF8ToString() conversion or something if field charset 
= UTF8.


> The question should be: Why does Firebird report 8 characters to your
> application ?

Only via FPC's SqlDB - not via FlameRobin. See above.


Regards,
   - Graeme -

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