fix: set foreign key constraints to OnDelete:SET NULL to avoid deletion errors

models/models.go

@@ -59,8 +59,8 @@ type Member struct {
 	CreatedByName string    `gorm:"type:varchar(100)" json:"created_by_name"`
 	CreatedAt     time.Time `gorm:"autoCreateTime" json:"created_at"`
 	Company       *Company  `gorm:"foreignKey:CompanyID" json:"company,omitempty"`
-	Branch      *Branch   `gorm:"foreignKey:BranchID" json:"branch,omitempty"`
-	CreatedBy   *User     `gorm:"foreignKey:CreatedByID" json:"created_by,omitempty"`
+	Branch      *Branch   `gorm:"foreignKey:BranchID;constraint:OnDelete:SET NULL;" json:"branch,omitempty"`
+	CreatedBy   *User     `gorm:"foreignKey:CreatedByID;constraint:OnDelete:SET NULL;" json:"created_by,omitempty"`
 }
 
 type PointHistory struct {
@@ -100,7 +100,7 @@ type User struct {
 	IsActive  bool      `json:"is_active"`
 	CreatedAt time.Time `gorm:"autoCreateTime" json:"created_at"`
 	Company   *Company  `gorm:"foreignKey:CompanyID" json:"company,omitempty"`
-	Branch    *Branch   `gorm:"foreignKey:BranchID" json:"branch,omitempty"`
+	Branch    *Branch   `gorm:"foreignKey:BranchID;constraint:OnDelete:SET NULL;" json:"branch,omitempty"`
 }
 
 type Category struct {
@@ -155,7 +155,7 @@ type Order struct {
 	PlatformFee     int         `gorm:"not null;default:0" json:"platform_fee"`
 	CreatedAt       time.Time   `gorm:"autoCreateTime" json:"created_at"`
 	Company         *Company    `gorm:"foreignKey:CompanyID" json:"company,omitempty"`
-	Branch          *Branch     `gorm:"foreignKey:BranchID" json:"branch,omitempty"`
+	Branch          *Branch     `gorm:"foreignKey:BranchID;constraint:OnDelete:SET NULL;" json:"branch,omitempty"`
 	MemberID        *uint       `gorm:"index" json:"member_id"`
 	Member          *Member     `gorm:"foreignKey:MemberID;references:ID;constraint:-" json:"member,omitempty"`
 	ServedBy        string      `gorm:"type:varchar(100)" json:"served_by"`