How to correct this error?

PS C:\Users\dddd\go\src\Hdddd> go run main.go
*******browse Handler running*******
2022/11/14 14:01:44 http: panic serving 127.0.0.1:65343: runtime error: invalid memory address or nil pointer dereference
goroutine 26 [running]:
net/http.(*conn).serve.func1()
        C:/Program Files/Go/src/net/http/server.go:1850 +0xbf
panic({0x8d9fe0, 0xbd0880})
        C:/Program Files/Go/src/runtime/panic.go:890 +0x262
database/sql.(*DB).conn(0x0, {0x9cad70, 0xc00009e010}, 0x1)
        C:/Program Files/Go/src/database/sql/sql.go:1288 +0x53

  1  package main
  2  
  3  import (
  4  	"database/sql"
  5  	"fmt"
  6  	"html/template"
  7  	"net/http"
  8  
  9  	_ "github.com/go-sql-driver/mysql"
 10  )
 11  
 12  type Employee struct {
 13  	Id             int
 14  	EmpName        string
 15  	Designation    string
 16  	DepartmentName string
 17  	PhoneNumber    string
 18  	Emailid        string
 19  }
 20  
 21  var tpl *template.Template
 22  
 23  var db *sql.DB
 24  var err error
 25  
 26  func main() {
 27  
 28  	tpl, err = template.ParseGlob("templates/*.html")
 29  
 30  	if err != nil {
 31  		fmt.Println(err.Error())
 32  	}
 33  
 34  	db, err := sql.Open("mysql", "root:Hdddd&@tcp(localhost:3306)/Embloyees")
 35  
 36  	if err != nil {
 37  		fmt.Println(err.Error())
 38  
 39  	}
 40  	defer db.Close()
 41  	//mux := http.NewRouter()
 42  	http.HandleFunc("/insert", insertHandler)
 43  	http.HandleFunc("/browse", browseHandler)
 44  	http.HandleFunc("/update", updateHandler)
 45  	http.HandleFunc("/delete", deleteHandler)
 46  	http.HandleFunc("/", homePageHandler)
 47  	http.ListenAndServe("localhost:8080", nil)
 48  
 49  }
 50  
 51  func browseHandler(w http.ResponseWriter, r *http.Request) {
 52  
 53  	fmt.Println("*******browse Handler running*******")
 54  	rows, err := db.Query("SELECT * FROM NewEmployee")
 55  	if err != nil {
 56  		panic(err)
 57  	}
 58  	defer rows.Close()
 59  	var employee []Employee
 60  	for rows.Next() {
 61  		var e Employee
 62  
 63  		err = rows.Scan(&e.Id, &e.EmpName, &e.Designation, &e.DepartmentName, &e.PhoneNumber, &e.Emailid)
 64  		if err != nil {
 65  			panic(err)
 66  		}
 67  		employee = append(employee, e)
 68  	}
 69  	tpl.ExecuteTemplate(w, "select.html", employee)
 70  }
 71  
 72  func insertHandler(w http.ResponseWriter, r *http.Request) {
 73  
 74  	fmt.Println("*******insert Handler running*******")
 75  	if r.Method == "GET" {
 76  		tpl.ExecuteTemplate(w, "insert.html", nil)
 77  		return
 78  	}
 79  	r.ParseForm()
 80  
 81  	name := r.FormValue("EmpName")
 82  	designation := r.FormValue("Designation")
 83  	department := r.FormValue("DepartmentName")
 84  	phone := r.FormValue("PhoneNumber")
 85  	Email := r.FormValue("Emailid")
 86  
 87  	if name == "" || designation == "" || department == "" || phone == "" || Email == "" {
 88  		fmt.Println("Error inseerting row:")
 89  		tpl.ExecuteTemplate(w, "insert.html", "Error inserting data, please check all fields.")
 90  		return
 91  	}
 92  	var ins *sql.Stmt
 93  	ins, err := db.Prepare("INSERT INTO NewEmployee ('EmpName', 'Designation', 'DepartmentName','PhoneNumber','Emailid') VALUES (?, ?, ?,?,?);")
 94  
 95  	if err != nil {
 96  		panic(err)
 97  	}
 98  	defer ins.Close()
 99  
100  	res, err := ins.Exec(name, designation, department, phone, Email)
101  
102  	rowsAffec, _ := res.RowsAffected()
103  	if err != nil || rowsAffec != 1 {
104  		fmt.Println("Error inserting row:", err)
105  		tpl.ExecuteTemplate(w, "insert.html", "Error inserting data, please check all fields.")
106  		return
107  	}
108  	lastInserted, _ := res.LastInsertId()
109  	rowsAffected, _ := res.RowsAffected()
110  	fmt.Println("ID of last row inserted:", lastInserted)
111  	fmt.Println("number of rows affected:", rowsAffected)
112  	tpl.ExecuteTemplate(w, "insert.html", "Product Successfully Inserted")
113  }
114  func updateHandler(w http.ResponseWriter, r *http.Request) {
115  
116  	fmt.Println("*****updateHandler running*****")
117  	r.ParseForm()
118  	id := r.FormValue("idemployee")
119  	row := db.QueryRow("SELECT * FROM NewEmbloyee WHERE idemployee = ?;", id)
120  	var e Employee
121  
122  	err := row.Scan(&e.Id, &e.EmpName, &e.Designation, &e.DepartmentName, &e.PhoneNumber, &e.Emailid)
123  	if err != nil {
124  		fmt.Println(err)
125  		http.Redirect(w, r, "/browse", http.StatusMovedPermanently)
126  		return
127  	}
128  	tpl.ExecuteTemplate(w, "update.html", e)
129  }
130  
131  func deleteHandler(w http.ResponseWriter, r *http.Request) {
132  
133  	fmt.Println("*****deleteHandler running*****")
134  	r.ParseForm()
135  	id := r.FormValue("idemployee")
136  
137  	del, err := db.Prepare("DELETE FROM NewEmployee WHERE ('idemployee' = ?);")
138  	if err != nil {
139  		panic(err)
140  	}
141  	defer del.Close()
142  	var res sql.Result
143  	res, err = del.Exec(id)
144  	rowsAff, _ := res.RowsAffected()
145  	fmt.Println("rowsAff:", rowsAff)
146  
147  		if err != nil || rowsAff != 1 {
148  			fmt.Fprint(w, "Error deleting product")
149  			return
150  		}
151  		fmt.Println("err:", err)
152  		tpl.ExecuteTemplate(w, "result.html", "Product was Successfully Deleted")
153  	}
154  func homePageHandler(w http.ResponseWriter, r *http.Request) {
155  
156  	http.Redirect(w, r, "/browse", http.StatusMovedPermanently)
157  }