I am trying to use the following code to add a column to a table.
ALTER IGNORE TABLE `EWRcarta_history`
ADD `history_ip` int(10) unsigned NOT NULL DEFAULT '0'
I am using IGNORE because for various reasons that I don't feel like getting into, this code may be called several times. I want to add the column, but ignore the error in case the column already exists. Instead of silently failing and moving on, 开发者_StackOverflowI get the following error:
#1060 - Duplicate column name 'history_ip'
Is there anything I can do to make this work?
I ended up using a function to handle this:
public static function addColumnIfNotExist($db, $table, $field, $attr)
{
if ($db->fetchRow('SHOW columns FROM `'.$table.'` WHERE Field = ?', $field))
{
return false;
}
return $db->query("ALTER TABLE `".$table."` ADD `".$field."` ".$attr);
}
and then of course I use the function as follows:
self::addColumnIfNotExist($db, "table", "column", "attributes");
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