hibernate - Grails 2.2.2未为参数2指定值

Question

这是我的问题。

我有3个域名类(class)

Contributor.groovy

class Contributor extends User{
    static hasMany = [instruments:Instrument]
}

Project.groovy

class Project {
    static hasMany = [instruments: Instrument]
    static belongsTo = [contributor: Contributor]
}

Instrument.groovy

class Instrument {
    static belongsTo = [Contributor, Project]
    static hasMany = [projects: Project, contributors: Contributor]
}

然后我有一个 服务，它具有一个功能来查找包含乐器列表的所有项目

def getProjectsByInstruments(){
        def result = null
        def instrument = Instrument.findByName("Accordion");
        def instrumentList = new HashSet<Instrument>();
        instrumentList.add(instrument)
        result = Project.findByInstruments(instrumentList)
        return result
}

当我执行该函数时，我得到以下错误消息:

2013-12-09 11:45:44,711 [http-bio-8081-exec-7] INFO  soundshare.ProjectController  - Entering Action /project/by_instrument
2013-12-09 11:45:44,712 [http-bio-8081-exec-7] INFO  soundshare.ProjectController  - Instrument : ACCORDION
2013-12-09 11:45:44,714 [http-bio-8081-exec-7] DEBUG hibernate.SQL  - select this_.id as id17_0_, this_.version as version17_0_, this_.name as name17_0_ from instrument this_ where this_.name=? limit ?
Hibernate: select this_.id as id17_0_, this_.version as version17_0_, this_.name as name17_0_ from instrument this_ where this_.name=? limit ?
2013-12-09 11:45:44,717 [http-bio-8081-exec-7] TRACE sql.BasicBinder  - binding parameter [1] as [VARCHAR] - Accordion
2013-12-09 11:45:44,717 [http-bio-8081-exec-7] TRACE sql.BasicExtractor  - found [1] as column [id17_0_]
2013-12-09 11:45:44,727 [http-bio-8081-exec-7] TRACE sql.BasicExtractor  - found [1] as column [version17_0_]
2013-12-09 11:45:44,727 [http-bio-8081-exec-7] TRACE sql.BasicExtractor  - found [Accordion] as column [name17_0_]
2013-12-09 11:45:44,729 [http-bio-8081-exec-7] DEBUG hibernate.SQL  - select this_.id as id31_0_, this_.version as version31_0_, this_.contributor_id as contribu3_31_0_, this_.description as descript4_31_0_, this_.musical_style_id as musical5_31_0_, this_.name as name31_0_, this_.open_to_public as open7_31_0_, this_.poster_url as poster8_31_0_ from project this_ where this_.id=? limit ?
Hibernate: select this_.id as id31_0_, this_.version as version31_0_, this_.contributor_id as contribu3_31_0_, this_.description as descript4_31_0_, this_.musical_style_id as musical5_31_0_, this_.name as name31_0_, this_.open_to_public as open7_31_0_, this_.poster_url as poster8_31_0_ from project this_ where this_.id=? limit ?
| Error 2013-12-09 11:45:44,729 [http-bio-8081-exec-7] ERROR util.JDBCExceptionReporter  - No value specified for parameter 2
| Error 2013-12-09 11:45:44,742 [http-bio-8081-exec-7] ERROR errors.GrailsExceptionResolver  - SQLException occurred when processing request: [POST] /project/by_instrument - parameters:
instrument: accordion
No value specified for parameter 2. Stacktrace follows:
Message: No value specified for parameter 2

谢谢你的帮助

Answer 1

试试这个查询

Project .withCriteria {
  instruments{
    eq('name', 'Accordion')
  }
}