Go语言结合Gin框架快速实现分页查询接口

go get -u gorm.io/gorm
go get -u gorm.io/driver/mysql
go get -u github.com/gin-gonic/gin

package main

import (
    "github.com/gin-gonic/gin"
    "gorm.io/driver/mysql"
    "gorm.io/gorm"
    "log"
    "net/http"
)

// User 用户模型
type User struct {
    ID    uint   `gorm:"primaryKey"`
    Name  string `gorm:"size:100"`
    Email string `gorm:"unique"`
    Age   int
}

var db *gorm.DB

func initDB() {
    dsn := "root:123456@tcp(127.0.0.1:3306)/testdb?charset=utf8mb4&parseTime=True&loc=Local"
    var err error
    db, err = gorm.Open(mysql.Open(dsn), &gorm.Config{})
    if err != nil {
        log.Fatal("数据库连接失败:", err)
    }
    // 自动迁移
    _ = db.AutoMigrate(&User{})
}

// 分页查询接口
func getUsers(c *gin.Context) {
    // 获取查询参数，默认 page=1, pageSize=10
    page := c.DefaultQuery("page", "1")
    pageSize := c.DefaultQuery("pageSize", "10")

    var (
        users []User
        total int64
    )

    // 转换为 int
    var p, ps int
    fmt.Sscanf(page, "%d", &p)
    fmt.Sscanf(pageSize, "%d", &ps)
    if p < 1 {
        p = 1
    }
    if ps < 1 {
        ps = 10
    }

    // 查询总数
    db.Model(&User{}).Count(&total)

    // 分页查询
    db.Offset((p - 1) * ps).Limit(ps).Find(&users)

    // 返回 JSON
    c.JSON(http.StatusOK, gin.H{
        "page":     p,
        "pageSize": ps,
        "total":    total,
        "data":     users,
    })
}

func main() {
    initDB()

    r := gin.Default()
    r.GET("/users", getUsers)

    r.Run(":8080")
}

curl "http://localhost:8080/users?page=2&pageSize=5"

{
  "page": 2,
  "pageSize": 5,
  "total": 23,
  "data": [
    {"ID":6,"Name":"Alice","Email":"alice@test.com","Age":22},
    {"ID":7,"Name":"Bob","Email":"bob@test.com","Age":25},
    {"ID":8,"Name":"Tom","Email":"tom@test.com","Age":20},
    {"ID":9,"Name":"Jerry","Email":"jerry@test.com","Age":30},
    {"ID":10,"Name":"Lucy","Email":"lucy@test.com","Age":19}
  ]
}