(Quick Reference)
                type
Purpose
Configures the Hibernate type for a particular property.
Examples
Changing to a text type (CLOB or TEXT depending on database dialect):
class Book {    String title    static mapping = {
        title type: "text"
    }
}User types with multiple columns:
class Book {
    …
    MonetaryAmount amount    static mapping = {
        amount type: MonetaryUserType, {
            column name: "value"
            column name: "currency", sqlType: "char", length: 3
        }
    }
}Description
Usage: 
association_name(type:string/class)Hibernate will attempt to automatically select the appropriate database type from the field typed based on configuration in the 
Dialect class that is being used. But you can override the defaults if necessary. For example 
String values are mapped by default to 
varchar(255) columns. To store larger 
String values you can use a 
text type instead:
static mapping = {
    title type: "text"
}Hibernate also has the concept of custom 
UserType implementations. In this case you specify the 
UserType class. If the 
UserType maps to multiple columns you may need to specify a mapping for each column:
static mapping = {
    amount type: MonetaryUserType, {
        column name: "value"
        column name: "currency", sqlType: "char", length: 3
    }
}