joinRel.Field = relation.Field
				joinRel.References = append(joinRel.References, &Reference{
					PrimaryKey: of,
					ForeignKey: f,
				})

				relation.References = append(relation.References, &Reference{
					PrimaryKey:    of,
					ForeignKey:    f,
					OwnPrimaryKey: true,
				})
			}

			if rf, ok := referFieldsMap[f.Name]; ok {

	// check fields
	fields := []schema.Field{
		{Name: "ID", DBName: "id", BindNames: []string{"Model", "ID"}, DataType: schema.Uint, PrimaryKey: true, Tag: `gorm:"primarykey"`, TagSettings: map[string]string{"PRIMARYKEY": "PRIMARYKEY"}, Size: 64, HasDefaultValue: true, AutoIncrement: true},
		{Name: "CreatedAt", DBName: "created_at", BindNames: []string{"Model", "CreatedAt"}, DataType: schema.Time},

				foreignFields = append(foreignFields, ref.PrimaryKey)
			} else if ref.PrimaryValue != "" {
				tx = tx.Where(clause.Eq{Column: ref.ForeignKey.DBName, Value: ref.PrimaryValue})
			} else {
				joinRelForeignFields = append(joinRelForeignFields, ref.ForeignKey)
				relForeignKeys = append(relForeignKeys, ref.PrimaryKey.DBName)
				relForeignFields = append(relForeignFields, ref.PrimaryKey)
			}
		}

				if ref.PrimaryValue == "" {
					if ref.OwnPrimaryKey {
						primaryFields = append(primaryFields, ref.PrimaryKey)
						joinPrimaryKeys = append(joinPrimaryKeys, ref.ForeignKey.DBName)
					} else {
						relPrimaryFields = append(relPrimaryFields, ref.PrimaryKey)
						joinRelPrimaryKeys = append(joinRelPrimaryKeys, ref.ForeignKey.DBName)
					}
				} else {

						if ref.OwnPrimaryKey {
							fv, _ := ref.PrimaryKey.ValueOf(db.Statement.Context, obj)
							db.AddError(ref.ForeignKey.Set(db.Statement.Context, joinValue, fv))
						} else if ref.PrimaryValue != "" {
							db.AddError(ref.ForeignKey.Set(db.Statement.Context, joinValue, ref.PrimaryValue))
						} else {
							fv, _ := ref.PrimaryKey.ValueOf(db.Statement.Context, elem)

				schema.FieldsByBindName[bindName] = field

				if v != nil && v.PrimaryKey {
					// remove the existing primary key field
					for idx, f := range schema.PrimaryFields {
						if f.DBName == v.DBName {
							schema.PrimaryFields = append(schema.PrimaryFields[0:idx], schema.PrimaryFields[idx+1:]...)
						}
					}
				}

				if field.PrimaryKey {
					schema.PrimaryFields = append(schema.PrimaryFields, field)
				}

					References: []Reference{
						{PrimaryKey: "ID", PrimarySchema: "Country", ForeignKey: "CountryID", ForeignSchema: "Org"},
					},
				},
			},
		},
		"VisitingAddress": {
			Relations: map[string]Relation{
				"Country": {
					Name: "Country", Type: schema.BelongsTo, Schema: "Org", FieldSchema: "Country",
					References: []Reference{

	if nullable, ok := columnType.Nullable(); ok && nullable == field.NotNull {
		// not primary key & current database is non-nullable(to be nullable)
		if !field.PrimaryKey && !nullable {
			alterColumn = true
		}
	}

	// check default value
	if !field.PrimaryKey {
		currentDefaultNotNull := field.HasDefaultValue && (field.DefaultValueInterface != nil || !strings.EqualFold(field.DefaultValue, "NULL"))

func (db *DB) First(dest interface{}, conds ...interface{}) (tx *DB) {
	tx = db.Limit(1).Order(clause.OrderByColumn{
		Column: clause.Column{Table: clause.CurrentTable, Name: clause.PrimaryKey},
	})
	if len(conds) > 0 {
		if exprs := tx.Statement.BuildCondition(conds[0], conds[1:]...); len(exprs) > 0 {
			tx.Statement.AddClause(clause.Where{Exprs: exprs})
		}
	}

				}

				if prefix, ok := field.TagSettings["EMBEDDEDPREFIX"]; ok && ef.DBName != "" {
					ef.DBName = prefix + ef.DBName
				}

				if ef.PrimaryKey {
					if !utils.CheckTruth(ef.TagSettings["PRIMARYKEY"], ef.TagSettings["PRIMARY_KEY"]) {
						ef.PrimaryKey = false

						if val, ok := ef.TagSettings["AUTOINCREMENT"]; !ok || !utils.CheckTruth(val) {
							ef.AutoIncrement = false
						}