GoFrame 链式操作-Handler特性
Handler特性允许您轻松地复用常见的逻辑。
示例1，查询
func AmountGreaterThan1000(m *gdb.Model) *gdb.Model {
return m.WhereGT("amount", 1000)
}
func PaidWithCreditCard(m *gdb.Model) *gdb.Model {
return m.Where("pay_mode_sign", "credit_card")
}
func PaidWithCod(m *gdb.Model) *gdb.Model {
return m.Where("pay_mode_sign", "cod")
}
func OrderStatus(statuses []string) func(m *gdb.Model) *gdb.Model {
return func(m *gdb.Model) *gdb.Model {
return m.Where("status", statuses)
}
}
var (
m = g.Model("product_order")
)
m.Handler(AmountGreaterThan1000, PaidWithCreditCard).Scan(&orders)
// SELECT * FROM `product_order` WHERE `amount`>1000 AND `pay_mode_sign`='credit_card'
// 查找所有金额大于 1000 的信用卡订单
m.Handler(AmountGreaterThan1000, PaidWithCod).Scan(&orders)
// SELECT * FROM `product_order` WHERE `amount`>1000 AND `pay_mode_sign`='cod'
// 查找所有金额大于 1000 的 COD 订单
m.Handler(AmountGreaterThan1000, OrderStatus([]string{"paid", "shipped"})).Scan(&orders)
// SELECT * FROM `product_order` WHERE `amount`>1000 AND `status` IN('paid','shipped')
// 查找所有金额大于1000 的已付款或已发货订单示例2，分页
func Paginate(r *ghttp.Request) func(m *gdb.Model) *gdb.Model {
return func(m *gdb.Model) *gdb.Model {
type Pagination struct {
Page int
Size int
}
var pagination Pagination
_ = r.Parse(&pagination)
switch {
case pagination.Size > 100:
pagination.Size = 100
case pagination.Size <= 0:
pagination.Size = 10
}
return m.Page(pagination.Page, pagination.Size)
}
}
m.Handler(Paginate(r)).Scan(&users)
m.Handler(Paginate(r)).Scan(&articles)