Handler特性允许您轻松地复用常见的逻辑。

示例1，查询

  1. func AmountGreaterThan1000(m *gdb.Model) *gdb.Model {
  2.     return m.WhereGT("amount", 1000)
  3. }
  5. func PaidWithCreditCard(m *gdb.Model) *gdb.Model {
  6.     return m.Where("pay_mode_sign", "credit_card")
  7. }
  9. func PaidWithCod(m *gdb.Model) *gdb.Model {
  10.     return m.Where("pay_mode_sign", "cod")
  11. }
  13. func OrderStatus(statuses []string) func(m *gdb.Model) *gdb.Model {
  14.     return func(m *gdb.Model) *gdb.Model {
  15.         return m.Where("status", statuses)
  16.     }
  17. }
  19. var (
  20.     m = g.Model("product_order")
  21. )
  23. m.Handler(AmountGreaterThan1000, PaidWithCreditCard).Scan(&orders)
  24. // SELECT * FROM `product_order` WHERE `amount`>1000 AND `pay_mode_sign`='credit_card'
  25. // 查找所有金额大于 1000 的信用卡订单
  27. m.Handler(AmountGreaterThan1000, PaidWithCod).Scan(&orders)
  28. // SELECT * FROM `product_order` WHERE `amount`>1000 AND `pay_mode_sign`='cod'
  29. // 查找所有金额大于 1000 的 COD 订单
  31. m.Handler(AmountGreaterThan1000, OrderStatus([]string{"paid", "shipped"})).Scan(&orders)
  32. // SELECT * FROM `product_order` WHERE `amount`>1000 AND `status` IN('paid','shipped')
  33. // 查找所有金额大于1000 的已付款或已发货订单

示例2，分页

  1. func Paginate(r *ghttp.Request) func(m *gdb.Model) *gdb.Model {
  2.     return func(m *gdb.Model) *gdb.Model {
  3.         type Pagination struct {
  4.             Page int
  5.             Size int
  6.         }
  7.         var pagination Pagination
  8.         _ = r.Parse(&pagination)
  9.         switch {
  10.         case pagination.Size > 100:
  11.             pagination.Size = 100
  13.         case pagination.Size <= 0:
  14.             pagination.Size = 10
  15.         }
  16.         return m.Page(pagination.Page, pagination.Size)
  17.     }
  18. }
  20. m.Handler(Paginate(r)).Scan(&users)
  21. m.Handler(Paginate(r)).Scan(&articles)