Question

I have a grails application using hibernate.Under grails 1.3.7 everything works properly, but when I switch to grails 2.0.3 the following problem appears:

I can’t check for unique fields under java/src directory. If I try to add or update any record with the same unique key, batch insert error appears.

Under src/groovy I create a class to check validation:

Example: LanguageCommand.groovy

package myproject.command

import org.codehaus.groovy.grails.validation.Validateable;

@Validateable
class LanguageCommand {

    String code
    String codeDescription

    static constraints= {
        code(blank:false, maxSize:50)
        codeDescription(maxSize:200)
    }
}

and under src/java I create a class to check for unique fields

Example: LanguageConstraints.groovy

package myproject.model

    constraints = {
        code unique: true
    }

where myproject.model is the name of the package that contains hibernate classes.

Note: Validation class works fine but the unique one not. i try to add unique constraints to validation class, same error appears

Error:

Error 500: Executing action [save] of controller 
           [myproject.controller.LanguageController] 
           caused exception: Runtime error executing action
Servlet: grails
URI: /myproject/grails/language/save.dispatch
Exception Message: Batch entry 0 insert into language 
                   (language_code, code_description, version, id) 
                   values (en, English, 0, 1) was aborted. 
                   Call getNextException to see the cause.
Caused by: Batch entry 0 insert into language 
           (language_code, code_description, version, id) 
           values (en, English, 0, 1) was aborted. 
           Call getNextException to see the cause.
Class: LanguageController
At Line: [125]
Code Snippet:

Any help?

Answer 1

Under src/groovy you will create a LanguageCommand.groovy class:

package myproject.command

import org.codehaus.groovy.grails.validation.Validateable;

@Validateable
class LanguageCommand {
    String oldCode
    String code
    String codeDescription

    static constraints= {
        code(maxSize:40, blank:false, validator: { val, obj ->
            if((obj.oldCode != val) && (Language.findWhere(code:val) != null))
                return['constraints.unique.code']
        })
        codeDescription(maxSize:200)
    }
}

and in i18n/messages.properties you must write (the message you want to display it):

constraints.unique.code = code must be unique

and in the controller in update method before check of validation you must write:

def update = {  
    LanguageCommand languageCommand ->
    Language languageInstance = Language.get(params.id)
    if(languageInstance) {
        languageCommand.oldCode = languageInstance.code
        if (!languageCommand.validate()){
            ...
            ...
        }
        ...
        ...
    }
    ...
    ...
}

Note: oldCode is a used in update only not in create, we store in it the code before updating, because if we search language by the code without changing it it return a result, then when the code = equal old code i we didn’t search language by code.

hope this help you