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grailsdatabase-migration

How to change a not nullable column to nullable in a Grails migration?

I need to change the columns currently not nullable to nullable using grails migration plugin. The dbm-gorm-diff command is throwing exception so what changeSet should I write to the changelog.

Solution 
  • class Student
{
String Name
String LName
String MName

static constraints={

Name(nullablel:false,required:true)
Lname(nullable:false,required:true)
Mname(nullable:true,required:false)   
}

}

    // by default if you dont specify nullable const it will always be nullable but assume we are going to generate migration scrip for this

    //inside your script let say change Mname to nullable

    databaseChangeLog = {

    changeSet(author: "developerName (generated)", id: "1369639981631-1") {
dropNotNullConstraint(columnDataType: "varchar(255)", columnName: "Mname", tableName: "student") 
 } 
     }