static mapping = {
currency column: "currency", sqlType: "char", length: 3
}column
Purpose
Customizes a column definition
Examples
Description
Usage: property_name(map)
Arguments:
-
column- The name of the column as a String -
sqlType(optional) - The underlying SQL type -
enumType(optional) - The enum type for type-safe Enum properties. Can beordinal,stringoridentity. -
index(optional) - The index name -
unique(optional) - Whether it is unique -
length(optional) - The length of the column -
precision(optional) - The precision of the column -
scale(optional) - The scale of the column -
comment(optional) - The comment for the column (used to create the table DDL) -
defaultValue(optional) - The database default value
By default GORM uses the property name and type to determine how to map a property in the database. For example a String property is typically mapped as a varchar(255) column. You can customize these with column configuration arguments:
static mapping = {
currency column: "currency", sqlType: "char", length: 3
}If you use a Hibernate type that requires multiple column definitions you can use the column method to define each column:
static mapping = {
amount type: MonetaryUserType, {
column name: "value"
column name: "currency", sqlType: "char", length: 3
}
}Note that if you have a static method that is the same name as one of your properties you are trying to configure or you use the same property name as one of the static GORM methods this can lead to conflicts. To avoid this scenario scope the mapping configuration using the delegate property:
static mapping = {
delegate.currency column: "currency", sqlType: "char", length: 3
}Mapping an Enum
The next example illustrates the different options to map an enum.
Given the next code:
package demo
import groovy.transform.CompileStatic
@CompileStatic
class BootStrap {
def init = { servletContext ->
Book.saveAll(
new Book(name: 'Grails 3 - Step by Step',
status: Status.NOT_SET),
new Book(name: 'Grails 3 - A practical guide to application development',
status: Status.BORROWED),
new Book(name: 'Falando de Grails',
status: Status.SOLD),
)
}
def destroy = { }
}package demo
import groovy.transform.CompileStatic
@CompileStatic
enum Status {
NOT_SET(-1),
BORROWED(0),
SOLD(1),
final int id
private Status(int id) { this.id = id }
}For enumType ordinal
package demo
class Book {
String name
Status status
static mapping = {
status enumType: 'ordinal'
}
}The enum will be mapped in the database as:
ID |
VERSION |
NAME |
STATUS |
1 |
0 |
Grails 3 - Step by Step |
0 |
2 |
0 |
Grails 3 - A practical guide to application development |
1 |
3 |
0 |
Falando de Grails |
2 |
For enumType identity
package demo
class Book {
String name
Status status
static mapping = {
status enumType: 'identity'
}
}The enum will be mapped in the database as:
ID |
VERSION |
NAME |
STATUS |
1 |
0 |
Grails 3 - Step by Step |
-1 |
2 |
0 |
Grails 3 - A practical guide to application development |
0 |
3 |
0 |
Falando de Grails |
1 |
For enumType string
package demo
class Book {
String name
Status status
static mapping = {
status enumType: 'string'
}
}The enum will be mapped in the database as:
ID |
VERSION |
NAME |
STATUS |
1 |
0 |
Grails 3 - Step by Step |
NOT_SET |
2 |
0 |
Grails 3 - A practical guide to application development |
BORROWED |
3 |
0 |
Falando de Grails |
SOLD |