2217qr4z

1package main
2
3import (
4	"database/sql"
5	"fmt"
6	"log"
7
8	_ "github.com/mattn/go-sqlite3"
9)
10
11var DbConnection *sql.DB
12
13type Person struct {
14	Name string
15	Age  int
16}
17
18func main() {
19	DbConnection, _ := sql.Open("sqlite3", "./example.sql")
20	cmd := `CREATE TABLE IF NOT EXISTS person(
21				name STRING,
22				age INT)`
23
24	_, err := DbConnection.Exec(cmd)
25	if err != nil {
26		log.Fatal(err)
27	}
28
29	//cmd = "INSERT INTO person (name, age) VALUES (?, ?)"
30	//_, err = DbConnection.Exec(cmd, "Nancy", 20)
31	//if err != nil {
32	//	log.Fatal(err)
33	//}
34
35	//cmd = "UPDATE person SET age = ? WHERE name = ?"
36	//_, err = DbConnection.Exec(cmd, 25, "Mike")
37	//if err != nil {
38	//	log.Fatal(err)
39	//}
40
41	//cmd = "SELECT * FROM person"
42	//rows, _ := DbConnection.Query(cmd)
43	//defer rows.Close()
44	//// パターンとして覚えておく。
45	//var pp []Person
46	//for rows.Next() {
47	//	var p Person
48	//	err := rows.Scan(&p.Name, &p.Age)
49	//	if err != nil {
50	//		log.Println(err)
51	//	}
52	//	pp = append(pp ,p)
53	//}
54	//err = rows.Err()
55	//if err != nil {
56	//	log.Fatal(err)
57	//}
58	//for _, p := range pp {
59	//	fmt.Println(p.Name, p.Age)
60	//}
61
62	//cmd = "SELECT * FROM person where age = ?"
63	//row := DbConnection.QueryRow(cmd, 1000)
64	//var p Person
65	//err = row.Scan(&p.Name, p.Age)
66	//if err != nil {
67	//	if err == sql.ErrNoRows{
68	//		log.Println("No row")
69	//	}else {
70	//		log.Println(err)
71	//	}
72	//}
73	//fmt.Println(p.Name, p.Age)
74
75	//cmd = "DELETE FROM person WHERE name = ?"
76	//_, err = DbConnection.Exec(cmd, "Nancy")
77	//if err != nil {
78	//	log.Fatal(err)
79	//}
80
81	tableName := "person"
82	cmd = fmt.Sprintf("SELECT * FROM %s", tableName)
83	rows, _ := DbConnection.Query(cmd)
84	defer rows.Close()
85	var pp []Person
86	for rows.Next() {
87		var p Person
88		err := rows.Scan(&p.Name, &p.Age)
89		if err != nil {
90			log.Println(err)
91		}
92		pp = append(pp, p)
93	}
94	err = rows.Err()
95	if err != nil {
96		log.Fatal(err)
97	}
98	for _, p := range pp {
99		fmt.Println(p.Name, p.Age)
100	}
101}