ZF-1: Quote SQL identifiers


(copied from TRAC #9 - reported by gwaihir gw h r.n t)

For you guys to ponder: the Zend framework doesn't currently quote the column names in its (My)SQL queries. This gives issues when using "special" characters in those names and thus I found myself haphazardly adding them: From: Zend/Db/Select.php

    public function __toString()
        //unchanged parts
        // add columns
        /** WH: Updated to quote column names in back-ticks (`). Needed for '-' in a column name.
         * Note that I am not sure how databases other than MySQL respond to those back-ticks.
         * Note also how - probably inefficiently - the select is for all columns by name, rather than *.
         * @todo: find a way to do this without altering the library code.
        if ($this->_parts['cols']) {
            $sql .= '`'. implode("`,\n\t`", $this->_parts['cols']) . "`\n";
        //more unchanged parts

If this affects other database systems differently than MySQL, then I dunno how / where this had best be done. If it doesn't hurt any of them, then please implement right away. :D I'm very exited about this development. PHP really lacks a "master" framework (like Ruby's Rails or some of Java's frameworks). I think the future success of the language rides on it (now that PHP5 already covers most other wishes). With kind regards, Wim Heemskerk


Previous change history from TRAC:

05/05/06 19:43:49: Modified by gavin

Also, the same problem arises in MySQL when column names use reserved words (e.g. timestamp).

Right or wrong, phpMyAdmin permits this, and some people do this.

06/03/06 04:36:47: Modified by mike

See also #92, issue is not limited to MySQL.

06/06/06 08:00:31: Modified by tony at

The same issue also applies to using reserved words (e.g. 'group') as table names in MySQL. Line 80 of Db/Adaptor/Pdo/Mysql.php should be changed from:

$sql = "DESCRIBE $table";


$sql = "DESCRIBE `$table`";

A more portable solution would be to use the adapter's quoteIdentifier method to quote column and table names:

public function __toString()


$cols = $this->_parts['cols'];
foreach($cols as $col_key => $col_val) {
    $cols[$col_key] = $this->_adapter->quoteIdentifier($col_val);


Changing fix version to 0.8.0.

Rewording summary.

Recategorize as Zend_Db_Table component.

As of revision 3897, all SQL generated by Zend_Db classes should quote identifiers.

You can use a Zend_Db_Expr to override an identifier if you don't want it quoted.