I am attempting to map a (small a part of a) Joomla MySQL database using GORM with Grails 2..

I am reading through a magazine around the argument (Grails) and searching the net for tech article, however i still require a good mention of the map Groovy/Java types to MySQL fields.

I am beginning having a simple table jos_bannerclient.

class BannerClient {
    String name
    String contact
    String email
    String notes
    String editor = ''

    static constraints = {

    static mapping = {
        datasource 'joomla'
        table 'jos_bannerclient'
        id column:'cid', type:'int'
        notes column:'extrainfo', type:'text'
        version false

At this time the record is produced within the database but when I save the domain with failOnError:true I recieve this error: java.lang.IllegalArgumentException.

I have problems mapping the checked_out TINYINT area. The only real factor for GORM to validate that area would be to declare it as being Boolean, why it doen't use Byte?

I have several doubt regarding how to map a MySQL TIME area like checked_out_time.

I have also read some a part of Hibernate documentation, but nonetheless not attaining the appropriate understanding to do this task!

Anybody might help please?

Regards, Giacomo