0x00 引言

再简单的事情，也需要有人去做。

0x01 代码

  1. package main
  3. import (
  4. 	"database/sql"
  5. 	"fmt"
  6. 	_ "github.com/mattn/go-sqlite3"
  7. 	"os"
  8. )
  10. func main() {
  12. 	type Person struct {
  13. 		name string
  14. 		age int
  15. 	}
  17. 	person := Person{"mike",18}
  18. 	fmt.Println(person)
  20. 	os.Remove("./foo.db")
  21. 	db, err := sql.Open("sqlite3", "./foo.db")
  22. 	checkErr(err)
  23. 	defer db.Close()
  24. 	//插入数据
  25. 	_, err = db.Exec("create table userinfo (uid text not null primary key, username text, departname text, created text)")
  26. 	checkErr(err)
  28. 	stmt, err := db.Prepare("INSERT INTO userinfo(uid, username, departname, created) values(?,?,?,?)")
  29. 	checkErr(err)
  30. 	defer stmt.Close()
  31. 	res, err := stmt.Exec("1", "astaxie", "研发部门", "2012-12-09")
  32. 	checkErr(err)
  33. 	id, err := res.LastInsertId()
  34. 	checkErr(err)
  35. 	fmt.Println(id)
  37. 	//更新数据
  38. 	stmt, err = db.Prepare("update userinfo set username=? where uid=?")
  39. 	checkErr(err)
  40. 	defer stmt.Close()
  41. 	res, err = stmt.Exec("astaxieupdate", id)
  42. 	checkErr(err)
  43. 	affect, err := res.RowsAffected()
  44. 	checkErr(err)
  45. 	fmt.Println(affect)
  47. 	//查询数据
  48. 	rows, err := db.Query("SELECT * FROM userinfo")
  49. 	checkErr(err)
  50. 	defer rows.Close()
  51. 	for rows.Next() {
  52. 		var uid int
  53. 		var username string
  54. 		var department string
  55. 		var created string
  56. 		err = rows.Scan(&uid, &username, &department, &created)
  57. 		checkErr(err)
  58. 		fmt.Println(uid)
  59. 		fmt.Println(username)
  60. 		fmt.Println(department)
  61. 		fmt.Println(created)
  62. 	}
  64. 	//删除数据
  65. 	stmt, err = db.Prepare("delete from userinfo where uid=?")
  66. 	checkErr(err)
  67. 	defer stmt.Close()
  68. 	res, err = stmt.Exec(id)
  69. 	checkErr(err)
  70. 	affect, err = res.RowsAffected()
  71. 	checkErr(err)
  72. 	fmt.Println(affect)
  73. 	db.Close()
  74. }
  76. func checkErr(err error) {
  77. 	if err != nil {
  78. 		panic(err)
  79. 	}
  80. }

0x02 错误处理

Golang 的这种检查错误的代码太多了，过度重复，一点都不优雅。Golang 2 对这种情况进行了改善。draft 给出的例子如下：

  1. func main() {
  2. 	hex, err := ioutil.ReadAll(os.Stdin)
  3. 	if err != nil {
  4. 		log.Fatal(err)
  5. 	}
  7. 	data, err := parseHexdump(string(hex))
  8. 	if err != nil {
  9. 		log.Fatal(err)
  10. 	}
  12. 	os.Stdout.Write(data)
  13. }

Golang 2的写法如下：

  1. func main() {
  2. 	handle err {
  3. 		log.Fatal(err)
  4. 	}
  6. 	hex := check ioutil.ReadAll(os.Stdin)
  7. 	data := check parseHexdump(string(hex))
  8. 	os.Stdout.Write(data)
  9. }

0x03 UPDATE

  1. 2019-01-15