As seen here => http://technet.microsoft.com/en-us/library/cc626307(v=sql.105).aspx

The PDO connection allow the instantiation of the connection even if the dbname
parameter isn't present. This change is there to make sure both behave the same way.

References:
SQLA16 - http://dcx.sybase.com/index.html#sa160/en/dbadmin/serverport-network-conparm.html
SQLA12 - http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.help.sqlanywhere.11.0.1/dbadmin_en11/serverport-network-conparm.html

Fixes the warning emitted by mysqli when sqlstate is not set (yet?).
http://git.php.net/?p=php-src.git;a=blob;f=ext/mysqli/mysqli_prop.c;h=2d36336372b75922bd8fbf40c5c9054a5230c8a0;hb=HEAD#l36

Warning masks actual connection error.

Change the name of the parameter instance_name by instancename

Hello, first sorry for my English. 
I need to put in the ORACLE Connection string to the parameter: (INSTANCE_NAME = XXXXX) 

I was reading the source code at github and the latest version does not include this possibility in the method getEasyConnectString. 

Could add to the next version an element in the array of parameters, eg $params['instance_name'] and concatenating that value to the Connection string? 

Thank you, greetings 
Facundo Panizza

Added flags support for mysqli::real_connect in Mysqli driver. This is necessary if you want to set connection options like compression or SSL encryption.