package main
import (
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "github.com/jmoiron/sqlx"
)
type Person struct {
    UserId   int    `db:"user_id"`
    Username string `db:"username"`
    Sex      string `db:"sex"`
    Email    string `db:"email"`
}
type Place struct {
    Country string `db:"country"`
    City    string `db:"city"`
    TelCode int    `db:"telcode"`
}
var Db *sqlx.DB
func init() {
    database, err := sqlx.Open("mysql", "root:root@tcp(127.0.0.1:3306)/test")
    if err != nil {
        fmt.Println("open mysql failed,", err)
        return
    }
    Db = database
    defer db.Close()  // 注意这行代码要写在上面err判断的下面
}
func main() {
    res, err := Db.Exec("update person set username=? where user_id=?", "stu0003", 1)
    if err != nil {
        fmt.Println("exec failed, ", err)
        return
    }
    row, err := res.RowsAffected()
    if err != nil {
        fmt.Println("rows failed, ",err)
    }
    fmt.Println("update succ:",row)
}
运行结果:
第一次运行:
    update succ: 1
    #受影响的行数 1第二次运行
    update succ: 0
    #受影响的行数 0文档更新时间: 2021-10-29 09:41   作者:kuteng