Gorm预加载时如何制定关联关系表中某个字段的值

结构体代码如下：

type UpgradeTask struct {
    Id          int      `json:"id" gorm:"primaryKey"`
    PreScripts  []Script `json:"pre_scripts" gorm:"many2many:yb_task_script_relation;ForeignKey:id;JoinForeignKey:task_id;References:id;JoinReferences:script_id;constraint:OnUpdate:CASCADE,OnDelete:CASCADE;"`
    PostScripts []Script `json:"post_scripts" gorm:"many2many:yb_task_script_relation;ForeignKey:id;JoinForeignKey:task_id;References:id;JoinReferences:script_id;constraint:OnUpdate:CASCADE,OnDelete:CASCADE;"`
}

type Script struct {
    Id         int    `json:"id" gorm:"primaryKey"`
    ScriptName string `json:"script_name"`
}

type TaskScript struct {
    Id         int `json:"-" gorm:"id;primaryKey"`
    TaskId     int `json:"task_id"`
    ScriptId   int `json:"script_id"`
    ScriptType int `json:"script_type"`
}

在UpgradeTask表中存在PreScripts和PostScripts字段信息，其中PreScripts为关联关系表TaskScript表中ScriptType为1的Script数据信息，PostScripts为关联关系表TaskScript表中ScriptType为2的Script数据信息，在查询UpgradeTask时需同时查询出该记录所对应的PreScripts和PostScripts信息，该怎么写代码？