How to join nested tables #5280
Description
Your Question
I have models like this:
package models
type ItemAsset struct {
ID int32 `gorm:"primary_key;AUTO_INCREMENT;column:id;type:int;" json:"id"`
ItemID string `gorm:"column:item_id;type:varchar;size:36;" json:"item_id"`
}
type ItemSet struct {
ID uint32 `gorm:"primary_key;AUTO_INCREMENT;column:id;type:uint;" json:"id"`
}
type Item struct {
ID int32 `gorm:"primary_key;AUTO_INCREMENT;column:id;type:int;" json:"id"`
ItemID string `gorm:"column:item_id;type:varchar;size:36;" json:"item_id"`
SetID null.Int `gorm:"column:set_id;type:uint;" json:"set_id"`
}
type PlayerItem struct {
ID int32 `gorm:"primary_key;AUTO_INCREMENT;column:id;type:int;" json:"id"`
PlayerID string `gorm:"column:player_id;type:varchar;size:128;" json:"player_id"`
ItemID string `gorm:"column:item_id;type:varchar;size:36;" json:"item_id"`
ItemLevelID null.Int `gorm:"column:item_level_id;type:uint;" json:"item_level_id"`
}
type ItemLevel struct {
ID uint32 `gorm:"primary_key;AUTO_INCREMENT;column:id;type:uint;" json:"id"`
ItemID string `gorm:"column:item_id;type:varchar;size:36;" json:"item_id"`
}And then i have another structure which combine all structure with relations
package entity
type Item struct {
models.Item
ItemAsset *models.ItemAsset `gorm:"foreignKey:ItemID;references:item_id" json:"item_asset"`
ItemSet *models.ItemSet `gorm:"foreignKey:ID;references:set_id" json:"item_set"`
}
type PlayerItem struct {
models.PlayerItem
Item Item `gorm:"foreignKey:ItemID;references:item_id" json:"item"`
ItemLevel *models.ItemLevel `gorm:"foreignKey:ItemLevelID;references:id" json:"item_level"`
}So my question is, how can i join nested models when i fetch entity.PlayerItem ?
Query like this is not working :(
db.
Joins("ItemLevel").
Joins("Item").
Joins("Item.ItemAsset").
Joins("Item.ItemSet").
Find(&items).
Yes, of course i know about Preload ! But it's generate separate query, but i want to join nested structure by LEFT JOIN query !