many2many has a question:Error 1075: Incorrect table definition; there can be only one auto column and it must be defined as a key

[fivenull]

Description

多对多关联，表迁移的时候，如果中间表对应的关联表不是主键id的话，创建会报错，报错内容为：

Error 1075: Incorrect table definition; there can be only one auto column and it must be defined as a key

例子：

type Area struct{
        ID        uint           `gorm:"primarykey"` // 主键ID
        Code     int           `json:"code" form:"code" gorm:"column:code;type:int"`
	Schools []School  `json:"schools" gorm:"many2many:school_areas;foreignKey:Code;joinForeignKey:area_id;references:ID;JoinReferences:school_system_id"`
}

type School struct{
        ID        uint           `gorm:"primarykey"` // 主键ID
        Areas []AreaModel `json:"areas" gorm:"many2many:school_areas;foreignKey:ID;joinForeignKey:school_system_id;references:Code;JoinReferences:area_id"`
}

其中中间表为school_areas表
2个主表

主表schools 的主键id字段，对应中间表的school_system_id字段
主表areas 的code字段，对应中间表的area_id字段

自动迁移的时候就会报错，生成的sql为

CREATE TABLE `school_areas` (`area_id` bigint COMMENT '省市编码',`school_system_id` bigint unsigned AUTO_INCREMENT,PRIMARY KEY (`area_id`,`school_system_id`))

数据库运行报1075错误，数据库版本为 5.7+
go版本为 1.16
gorm版本为 v1.21.12

[fivenull]

schools表和areas表主键都需要设置自增

[a631807682]

duplicated of #5320
upgrade gorm version