如何利用golang运用mysql数据库

import (
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql"
)

package main

import (
    _ "container_cloud/pkg/config"
    "container_cloud/pkg/utils/httputil"
    "container_cloud/routers"
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "net/http"
    "time"
)

func init() {
    httputil.InitHttpTool()
}

// mysql
const (
    USERNAME = "root"
    PASSWORD = "Admin123"
    NETWORK  = "tcp"
    // TODO  本地调试时放开
    /*SERVER   = "192.168.103.48"
    PORT     = 43306*/

    // TODO 部署到环境时放开
    SERVER   = "192.168.66.4"
    PORT     = 3306
    DATABASE = "container_cloud"
)

func main() {
    var err error
    dsn := fmt.Sprintf("%s:%s@%s(%s:%d)/%s?parseTime=1&multiStatements=1&charset=utf8mb4&collation=utf8mb4_unicode_ci", USERNAME, PASSWORD, NETWORK, SERVER, PORT, DATABASE)

    db, err := sql.Open("mysql", dsn)
    if err != nil {
        fmt.Printf("Open mysql failed,err:%v
", err)
        return
    }
    //最大连接周期，超过时间的连接就close
    db.SetConnMaxLifetime(100 * time.Second)
    //设置最大连接数
    db.SetMaxOpenConns(100)
    //设置闲置连接数
    db.SetMaxIdleConns(16)

    defer db.Close()

    container := routers.InitApiRouter(db)
    server := &http.Server{Addr: ":8090", Handler: container}
    server.ListenAndServe()
}

package v1alpha1

import (
    "container_cloud/pkg/api"
    "container_cloud/pkg/apiserver/query"
    "container_cloud/pkg/apiserver/runtime"
    "container_cloud/pkg/controller"
    "container_cloud/pkg/domain"
    "database/sql"
    "github.com/emicklei/go-restful"
    "k8s.io/apimachinery/pkg/runtime/schema"
    "net/http"
)

const (
    GroupName = "order.ictnj.io"
    Version   = "v1alpha1"
)

var GroupVersion = schema.GroupVersion{Group: GroupName, Version: Version}

func AddToContainer(db *sql.DB) *restful.WebService{
    ws := runtime.NewWebService(GroupVersion)
    orderController := controller.NewOrderController(db)

    // 创建订单接口，pvc创建、负载创建的时候，是在特定命名空间下。（其实请求入参中也有命名空间字段，资源创建的时候也可以从入参中获取）
    ws.Route(ws.POST("/namespaces/{namespace}/orders").
        To(orderController.CreateOrder).
        Param(ws.PathParameter("namespace", "namespace name")).
        Returns(http.StatusOK, api.StatusOK, map[string]string{}).
        Doc("create order."))

    return ws
}

type orderController struct {
    Db *sql.DB
}

func NewOrderController(db *sql.DB) *orderController{
    return &orderController{Db: db}
}

// 再创建订单
    orderService := service.NewOrderService(o.Db)
    orderService.CreateOrder(order)
    result := map[string]string{"message": "success"}
    response.WriteEntity(result)

package service

import (
    "container_cloud/pkg/api"
    "container_cloud/pkg/apiserver/query"
    "container_cloud/pkg/domain"
    "database/sql"
    "encoding/json"
    "fmt"
    "github.com/google/uuid"
    "k8s.io/klog"
    "strings"
    "time"
)

type OrderService struct {
    Db *sql.DB
}

func NewOrderService(db *sql.DB) *OrderService{
    return &OrderService{Db: db}

}
func (o *OrderService) CreateOrder(order domain.Order) {
    order.CreateTime = time.Now()
    var orderType uint8 = 1
    order.OrderType = &orderType
    uuid,_ := uuid.NewRandom()
    order.Id = strings.ReplaceAll(uuid.String(), "-", "")

    jsonbyte, _ := json.Marshal(order.OrderItem)
    order.OrderItemJson = string(jsonbyte)

    o.insertData(order)
}

func (o *OrderService) insertData(order domain.Order) {
    stmt, _ := o.Db.Prepare(`INSERT INTO t_order (id, username, service_type, order_type, status, reason, order_item, create_time) VALUES (?, ?, ?, ?, ?, ?, ?, ?)`)
    defer stmt.Close()

    ret, err := stmt.Exec(order.Id, order.Username, order.ServiceType, order.OrderType, order.Status, order.Reason, order.OrderItemJson, order.CreateTime)
    if err != nil {
        fmt.Printf("insert data error: %v
", err)
        return
    }
    if LastInsertId, err := ret.LastInsertId(); nil == err {
        fmt.Println("LastInsertId:", LastInsertId)
    }
    if RowsAffected, err := ret.RowsAffected(); nil == err {
        fmt.Println("RowsAffected:", RowsAffected)
    }
}

func (o *OrderService) ListOrders(query *query.Query, username string) (*api.ListResult, error){
    // 查询总数量
    totalRow, err := o.Db.Query("SELECT COUNT(*) FROM t_order WHERE username = ?", username)
    if err != nil {
        klog.Error("query orders count error", err)
        return nil, err
    }
    total := 0
    for totalRow.Next() {
        err := totalRow.Scan(
            &total,
        )
        if err != nil {
            klog.Error("query orders count error", err)
            continue
        }
    }
    totalRow.Close()

    // 查询订单列表
    rows, err := o.Db.Query("select * from t_order where username = ? order by create_time desc limit ? offset ? ", username, query.Pagination.Limit, query.Pagination.Offset)
    defer func() {
        if rows != nil {
            rows.Close()
        }
    }()
    if err != nil {
        klog.Error("query orders error", err)
        return nil, err
    }

    items := make([]interface{}, 0)
    for rows.Next() {
        order := new(domain.Order)
        err = rows.Scan(&order.Id, &order.Username, &order.ServiceType, &order.OrderType, &order.Status, &order.Reason, &order.OrderItemJson, &order.CreateTime)
        if err != nil {
            klog.Error("query orders error", err)
            return nil, err
        }
        order.OrderItemJson = ""
        items = append(items, *order)
    }

    return &api.ListResult{
        TotalItems: total,
        Items:      items,
    }, nil

}

func (o *OrderService) GetOrder(id string) (*domain.Order, error) {
    order := new(domain.Order)
    row := o.Db.QueryRow("select order_item from t_order where id = ?", id)
    if err := row.Scan(&order.OrderItemJson); err != nil {
        klog.Error(err)
        return nil, err
    }
    orderItems := &[]domain.OrderItem{}
    json.Unmarshal([]byte(order.OrderItemJson), orderItems)

    order.OrderItemJson = ""
    order.OrderItem = *orderItems
    return order, nil
}


func (o *OrderService) ListUserOrders(username string) (*[]domain.Order, error){
    // 查询订单列表
    rows, err := o.Db.Query("select * from t_order where username = ? order by create_time desc", username)
    defer func() {
        if rows != nil {
            rows.Close()
        }
    }()
    if err != nil {
        klog.Error("query orders error", err)
        return nil, err
    }
    items :=  make([]domain.Order,0)
    for rows.Next() {
        order := new(domain.Order)
        err = rows.Scan(&order.Id, &order.Username, &order.ServiceType, &order.OrderType, &order.Status, &order.Reason, &order.OrderItemJson, &order.CreateTime)
        if err != nil {
            klog.Error("query orders error", err)
            return nil, err
        }
        order.OrderItemJson = ""
        items = append(items, *order)
    }

    return &items,nil
}