object query(string poolName, string querystring, [ object parameters, ... ] )

Executes a query in a given connection which is acquired from configured pool named 'poolName'. 'poolName' may also contains database catalog, separated with colon from the name of pool. For instance, "mypool:mycatalog".

'querystring' is parsed so that given parameters are embedded to placeholders in string.

Placeholders:

? Embeds next parameter according to its type (i.e. strings are escaped and quoted)
$ Embeds next parameter as it is (result of tostring())

Parameters	`poolName -` Name of connection pool, may contain database catalog `querystring -` query string `parameters -` to be embedded
Returns	`null` if error occurred, `ResultSet` if 'querystring' was an select query (or similar), otherwise returns update count as integer.
Throws	`AcquireError -` If connection could not be retrieved `SQLError -` If SQL error occured