Here still a few information to the problem:
- Database: Sybase Anywhere Version 7
- Webserver: Apache 2.0 with OpenSSL
- ODBC: Version 3.520

In the meantime I found still out that the problem arises, if the column from a Subquery were 

produced.

Query sample:
select distinct a.column1, a.column2,

(select List(b.column1) from Table2 as b 
where b.Prim = a.Prim) as ListColumn

from Table1 as a
where a.Prim = 1

Don't mind sniper, he's a little over-zealous with the bogus-ification.  You're correct though that SELECT DISTINCT does create problems with the ODBC system at the moment.  I haven't yet been able to figure out why.

Any chance you can create a log of the SQL transactions (SQL Log option on your ODBC Administrator) and post it here?

Complete Logfile is very long, here is the part of interest:

                750-b24	ENTER SQLGetData 
		HSTMT               00EC1DB0
		UWORD                        9 
		SWORD                        1 <SQL_C_CHAR>
		PTR                 0x053E8620 
		SQLLEN                  4096
		SQLLEN *            0x0595C5E4

                750-b24	EXIT  SQLGetData  with return code 0 (SQL_SUCCESS)
		HSTMT               00EC1DB0
		UWORD                        9 
		SWORD                        1 <SQL_C_CHAR>
		PTR                 0x053E8620 [      11] "521 (70074)" --> first odbc_result here
		SQLLEN                  4096
		SQLLEN *            0x0595C5E4 (11)

                750-b24	ENTER SQLGetData 
		HSTMT               00EC1DB0
		UWORD                        9 
		SWORD                        1 <SQL_C_CHAR>
		PTR                 0x053E9638 
		SQLLEN                  4096
		SQLLEN *            0x0595C5E4

                750-b24	EXIT  SQLGetData  with return code 100 (SQL_NO_DATA_FOUND) --> ERROR here ???
		HSTMT               00EC1DB0
		UWORD                        9 
		SWORD                        1 <SQL_C_CHAR>
		PTR                 0x053E9638 
		SQLLEN                  4096
		SQLLEN *            0x0595C5E4

                750-b24	ENTER SQLExtendedFetch 
		HSTMT               00EC1DB0
		UWORD                        1 <SQL_FETCH_NEXT>
		SQLROWOFFSET               1
		SQLROWSETSIZE *     0x0520F318
		UWORD *             0x0520F320

                750-b24	EXIT  SQLExtendedFetch  with return code 0 (SQL_SUCCESS)
		HSTMT               00EC1DB0
		UWORD                        1 <SQL_FETCH_NEXT>
		SQLROWOFFSET               1
		SQLROWSETSIZE *     0x0520F318 (1)
		UWORD *             0x0520F320 (0)

Just to make sure, this is using the example you've posted above, not some deviation, right?

Please apology for the long waiting period...

Right !

I learned in the meantime that this can be produced in different ways. I could cause the effect with List(ColumnX) and with a Subquery as column. I suppose the error occurs, when the fieldtype is not defined by a field from a table of the database.

Supplement...

The error occures by:
"SELECT List(ColumnX) as IDENT from TableA"

you can bypass the problem when doing the following:
"SELECT cast(List(Column) as varchar(1000)) as IDENT from TableA"

Samplecode:
<?php

echo "Connect to database...";

$iddb = odbc_connect('db1','user1','user1');
echo "OK<br>";

if ( $iddb == 0 ) {
   echo "Error: Cannot connect to database.";
   exit;
};

$sqlqry = "select List(ColumnA) as ColumnX from TableA";

echo "<hr>$sqlqry<br>";

$idresult = odbc_exec($iddb, $sqlqry);

$qryeof = odbc_fetch_row($idresult);
if ( !$qryeof ) {
    echo "no result";
} else {
    echo "Version 1 / Result 1: " . odbc_result($idresult, "ColumnX") . "<br><br>";
    echo "Version 1 / Result 2: " . odbc_result($idresult, "ColumnX") . "<br><br>";
};

$sqlqry = "select cast(List(ColumnA) as varchar(1000)) as ColumnX from TableA";

echo "<hr>$sqlqry<br>";

$idresult = odbc_exec($iddb, $sqlqry);

$qryeof = odbc_fetch_row($idresult);
if ( !$qryeof ) {
    echo "no result";
} else {
    echo "Version 2 / Result 1: " . odbc_result($idresult, "ColumnX") . "<br><br>";
    echo "Version 2 / Result 2: " . odbc_result($idresult, "ColumnX") . "<br><br>";
};

odbc_close($iddb);

?>

Result of Samplecode:
Connect to database...OK

------------------------------------------------------------
select List(ColumnA) as ColumnX from TableA
Version 1 / Result 1: res1,res2,res3

Version 1 / Result 2: 


------------------------------------------------------------
select cast(List(ColumnA) as VarChar(1000)) as ColumnX from TableA
Version 2 / Result 1: res1,res2,res3

Version 2 / Result 2: res1,res2,res3

Please try using this CVS snapshot:

  http://snaps.php.net/php4-STABLE-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php4-win32-STABLE-latest.zip

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