I have a domain like this:

class BusinessOrganization {

    static hasMany = [organizationBusinessTypes:OrganizationBusinessType]

    String name
    String icon

    static constraints = {
        name(blank:false,unique:true)
        icon(unique:true)
    }

    String toString() {
        return "${name}"
    }

}

When I save some data for first time it works fine. But when by the next time it shows this error :

Error 500: Internal Server Error
URI /nLocatePortal/businessOrganization/save
Class java.sql.BatchUpdateException
Message Batch entry 0 insert into business_organization (version, icon, name, id) values ('0', '', 'dddd', '2') was aborted. Call getNextException to see the cause.

**Around line 24 of grails-app/controllers/com/nlocate/portal/BusinessOrganizationController.groovy**
21:
22:    def save() {
23:        def businessOrganizationInstance = new BusinessOrganization(params)
24:        if (!businessOrganizationInstance.save(flush: true)) {
25:            render(view: "create", model: [businessOrganizationInstance: businessOrganizationInstance])
26:            return
27:        }

Please someone help me why this is happening. I am new to Grails. I have not modified the controllers but still I get this error.