Question

我们在使用Grails（2.3.7）时遇到问题，它与Criteria Queries和映射有关。问题是在定义标准并尝试列出结果之后，Hibernate似乎没有将映射表添加到查询中，因此查询失败。

现在我们有3个相关的表：Users，Competitions + UserCompetition，它们在具有复合主键的其他2个表之间具有关系，并且将每两个表作为外键引用。

这里有我们域名的定义：

class User {
(...)
static hasMany = [competitions:Competition]

static mapping = {
    table "users"
(...)
    competitions joinTable: [name: 'usersCompetitions',
        key: 'userId',
        column: 'competitionId']
}


class Competition {
(...)
static hasMany = [users:User]

static belongsTo = User

static mapping = {
    table "competitions"
    id column: 'competitionId'
    users joinTable: [name: 'usersCompetitions',
        key: 'competitionId',
        column: 'userId']
}
}


class UserCompetition implements Serializable {

private static final long serialVersionUID = 1

Competition competition
User user
boolean planning

static mapping = {
    table "usersCompetitions"
    id composite: ['user', 'competition']
    competition column: 'competitionId'
    user column: 'userId'
}


boolean equals(other) {
    if (!(other instanceof UserCompetition)) {
        return false
    }

    other.user?.id == user?.id &&
            other.competition?.id == competition?.id
}

int hashCode() {
    def builder = new HashCodeBuilder()
    if (user) builder.append(user.id)
    if (competition) builder.append(competition.id)
    builder.toHashCode()
}

static UserCompetition get(long userId, long competitionId) {
    UserCompetition.where {
        user == User.load(userId) &&
                competition == Competition.load(competitionId)
    }.get()
}

}

最后，我们尝试使用Criteria从UserCompetitions中检索一些数据：

def c = UserCompetition.createCriteria()
def competitions = c.list{
        createAlias("competition", "comp")
        and{
            isNotNull("comp.startDate")
            gt("comp.startDate", now)
        }
        eq("user.id",user.id)
        ne("planning",true)
        maxResults(3)
        order("comp.startDate", "asc")
    }

这就是我们得到的：

Message: Unknown column 'comp1_.startDate' in 'where clause'

这是Hibernate生成的查询，正如您所看到的，它没有添加与Competition表的关系：

select this_.userId as userId0_0_, this_.competitionId as competit2_0_0_, this_.planning as planning0_0_ from usersCompetitions this_ where (comp1_.startDate is not null and comp1_.startDate>?) and this_.userId=? and this_.planning<>? order by comp1_.startDate asc limit ?

我们正在努力了解最新情况，但我们无法理解为什么Hibernate没有将映射表添加到查询中： - ？

提前致谢，

Answer 1

问题与Grails如何解释使用joinTable的所有映射有关。

我们删除了joinTable和User域类中的所有Competition个引用，并通过UserCompetition而不是彼此链接它们，并且查询开始起作用。< / p>

class User {
(...)
static hasMany = [competitions:UserCompetition]

static mapping = {
    table "users"
(...)
    /* competitions joinTable: [name: 'usersCompetitions',
        key: 'userId',
        column: 'competitionId'] */
}


class Competition {
(...)
static hasMany = [users:UserCompetition]

static belongsTo = User

static mapping = {
    table "competitions"
    id column: 'competitionId'
    /* users joinTable: [name: 'usersCompetitions',
        key: 'competitionId',
        column: 'userId'] */
}
}

Grails：条件查询在连接表上失败？

1 个答案: