go连接mysql产生大量连接

一直是这个问题困扰着哦我，为什么越来越多连接，到爆掉，换作postgresql驱动也是，还是我理解go语言并发有错呢 package main import ( "database/sql" "fmt" _ "github.com/go-sql-driver/mysql" "strconv" "time" ) var xiancheng = 10 var over = make(chan bool) var sem = make(chan int, xiancheng) func checkErr(err error, hh int) { if err != nil { fmt.Printf("error "+strconv.Itoa(hh)+"\n", err) panic(err) } } func getMySQL2() *sql.DB { db, err := sql.Open("mysql", "root:123456789@tcp(127.0.0.1:3306)/getbbs?charset=utf8") checkErr(err, 999) return db } func work(aa int) string { sem <- 1 dbx := getMySQL2() defer dbx.Close() _, e2 := dbx.Query("select 1") if e2 == nil { println("DB OK:", aa) } time.Sleep(time.Second * 1) fmt.Println("work id:", aa) if aa == 9999 { gocheck2() } <-sem return "ok" } func gocheck2() { over <- true } func main() { for i := 0; i < 10000; i++ { go work(i) } <-over } 请这里的高手帮帮忙