Zend DB Framework examine query for an update

问题:

So you can use something like this:

$query = $db->select();
$query->from('pages', array('url'));
echo $query->__toString();

to examine the sql that the Zend Db Framework is going to use for that SELECT query. Is there an equivilent way to view the SQL for an update?

$data = array(
   'content'      => stripslashes(htmlspecialchars_decode($content))
);      
$n = $db->update('pages', $data, "url = '".$content."'");
??

回答1:

Use Zend_Db_Profiler to capture and report SQL statements:

$db->getProfiler()->setEnabled(true);
$db->update( ... );
print $db->getProfiler()->getLastQueryProfile()->getQuery();
print_r($db->getProfiler()->getLastQueryProfile()->getQueryParams());
$db->getProfiler()->setEnabled(false);

Remember to turn the profiler off if you don't need it! I talked to one fellow who thought he had a memory leak, but it was the profiler instantiating a few PHP objects for each of the millions of SQL queries he was running.

PS: You should use quoteInto() in that query:

$n = $db->update('pages', $data, $db->quoteInto("url = ?", $content));

回答2:

No, not directly, since Zend Framework builds and executes the SQL inside the adapter method Zend_Db_Adapter_Abstract::update:

/**
 * Updates table rows with specified data based on a WHERE clause.
 *
 * @param  mixed        $table The table to update.
 * @param  array        $bind  Column-value pairs.
 * @param  mixed        $where UPDATE WHERE clause(s).
 * @return int          The number of affected rows.
 */
public function update($table, array $bind, $where = '')
{
    /**
     * Build "col = ?" pairs for the statement,
     * except for Zend_Db_Expr which is treated literally.
     */
    $set = array();
    foreach ($bind as $col => $val) {
        if ($val instanceof Zend_Db_Expr) {
            $val = $val->__toString();
            unset($bind[$col]);
        } else {
            $val = '?';
        }
        $set[] = $this->quoteIdentifier($col, true) . ' = ' . $val;
    }

    $where = $this->_whereExpr($where);

    /**
     * Build the UPDATE statement
     */
    $sql = "UPDATE "
         . $this->quoteIdentifier($table, true)
         . ' SET ' . implode(', ', $set)
         . (($where) ? " WHERE $where" : '');

    /**
     * Execute the statement and return the number of affected rows
     */
    $stmt = $this->query($sql, array_values($bind));
    $result = $stmt->rowCount();
    return $result;
}

You can, temporarily, insert a var_dump and exit inside this method to inspect the sql to ensure that it is correct:

/**
 * Build the UPDATE statement
 */
 $sql = "UPDATE "
         . $this->quoteIdentifier($table, true)
         . ' SET ' . implode(', ', $set)
         . (($where) ? " WHERE $where" : '');
 var_dump($sql); exit;

回答3:

I quess another way is to log the actual SQL query, rather than changing the ZF library code, by combining the profiler data.

$db->getProfiler()->setEnabled(true);

$db->update( ... );

$query = $db->getProfiler()->getLastQueryProfile()->getQuery();

$queryParams = $db->getProfiler()->getLastQueryProfile()->getQueryParams();

$logger->log('SQL: ' . $db->quoteInto($query, $queryParams), Zend_Log::DEBUG);

$db->getProfiler()->setEnabled(false);

回答4:

Recently came across this looking for a way to debug a zend_db_statement. If anyone else comes across this with the same search, you can use the following function.

Just replace "self::getDefaultAdapter()" with your method of getting a DB connection or adapter.

/**
 * replace any named parameters with placeholders
 * @param string $sql sql string with placeholders, e.g. :theKey
 * @param array $bind array keyed on placeholders, e.g. array('theKey', 'THEVALUE')
 * 
 * @return String sql statement with the placeholders replaced
 */
public static function debugNamedParamsSql($sql, array $bind) {
    $sqlDebug = $sql;
    foreach($bind as $needle => $replace) {
        $sqlDebug = str_replace( 
                                ':' . $needle, 
                                self::getDefaultAdapter()->quote($replace), 
                                $sqlDebug
        );
    }        
    return $sqlDebug;        
}