Thank you for this bug report. To properly diagnose the problem, we
need a short but complete example script to be able to reproduce
this bug ourselves. 

A proper reproducing script starts with <?php and ends with ?>,
is max. 10-20 lines long and does not require any external 
resources such as databases, etc. If the script requires a 
database to demonstrate the issue, please make sure it creates 
all necessary tables, stored procedures etc.

Please avoid embedding huge scripts into the report.

Please give the SQL to create the table and a non-ZFW testcase.  Thanks.

Looks OK in my testcase.

<?php

/*
create table cjt (c1 number unique);
insert into cj1 values (1);
commit;
*/

error_reporting(E_ALL);
ini_set('display_errors', 'Off');

$c = oci_connect('hr', 'welcome', 'localhost/orcl');

if (!$c) {
    $m = oci_error();
    trigger_error('oci_connect error: Could not connect to database: '. $m['message'], E_USER_ERROR);
}

$s = oci_parse($c, "insert into cjt values (1)");
if (!$s) {
    $m = oci_error($c);
    trigger_error('oci_parse error: Could not parse statement: '. $m['message'], E_USER_ERROR);
}

$r = oci_execute($s);
if (!$r) {
    $m = oci_error($s);
    trigger_error('oci_execute error: Could not execute statement: '. $m['message'], E_USER_ERROR);
}

?>

Gives:

$ php56 uc.php
PHP Warning:  oci_execute(): ORA-00001: unique constraint (HR.SYS_C0010813) violated in uc.php on line 25
PHP Fatal error:  oci_execute error: Could not execute statement: ORA-00001: unique constraint (HR.SYS_C0010813) violated in uc.php on line 28

Closing this issue.

Thanks to the boiled-down test script above, we were able to run the test in a couple scenarios. We discovered it's apparently an issue in Zend Server's ZRay debug tool. With ZRay on, the oci_error info was disappearing. As soon as ZRay was turned off, the error info started appearing in the exception as expected.