Postgres的“ RAISE EXCEPTION”如何转换为PDOException？

Question

I am trying to figure out which "parts" of "RAISE EXCEPTION" statement gets mapped into which "parts" of PDOException. Can some one explain "who" and "how" perform this conversion (or better yet, point to document which describes this or source code which performs this)?

More specifically, I would like to know if there is a way to affect SQLSTATUS value (in my tests its always 'P0001') and/or 'ERROR:' value (which is part of the message and is always empty)

Best I could manage is:

RAISE EXCEPTION USING message = '<a message>', ERRCODE = 'UE001'

which on PHP side gives me message like:

ERROR:  NUM:UE001, DETAILS:<a message>

But I am not very happy with this. It would be great to be able to "put" 'UE001' into one of PDOException fields (so I do not have to parse it out of message string).

You comments will be highly appreciated.

Answer 1

Use the code property of PDOException to get the SQLSTATE . See the documentation for PDOException

To control the SQLSTATE generated by a PL/PgSQL function raising an error, you use RAISE ... SQLSTATE as per the documentation .

Of course, for this to work the database driver must correctly report SQLSTATE . I have verified that PDO does this at least in PHP 5.4.11 with PostgreSQL 9.2, per the following standalone example code that can be executed with the php command-line executable:

<?php
$pdo = new PDO('pgsql:');

$sql = <<<EOD
CREATE OR REPLACE FUNCTION exceptiondemo() RETURNS void AS $$
BEGIN
  RAISE SQLSTATE 'UE001' USING MESSAGE = 'error message';
END;
$$ LANGUAGE plpgsql
EOD;

$sth = $pdo->prepare($sql);
if (!$sth->execute()) {
        die("Failed to create test function\n");
}

$sql = "SELECT exceptiondemo();";

$sth = $pdo->prepare($sql);
if (!$sth->execute()) {
        $ei = $sth->errorInfo();
        die("Function call failed with SQLSTATE " . $ei[0] . ", message " . $ei[2] . "\n");

        // Shortcut way:
        // die("Function call failed with SQLSTATE " . $sth->errorCode());
}
?>

Output is:

Function call failed with SQLSTATE UE001, message ERROR:  error message

Replace the code block from the second $sth->execute() to the end of the code with this to demonstrate that the exception handling mode works fine too:

$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
try {
        $sth->execute();
} catch (PDOException $err) {
        $ei = $err->errorInfo;
        die("Function call failed with SQLSTATE " . $ei[0] . ", message " . $ei[2] . "\n");

        // Alternate version to just get code:
        //die("Function call failed with SQLSTATE " . $err->getCode() . "\n");
}