add example

This commit is contained in:
Yasuhiro Matsumoto 2024-01-25 22:12:05 +09:00 committed by mattn
parent cdc8095814
commit 64bbe6202c
1 changed files with 81 additions and 0 deletions

81
_example/json/json.go Normal file
View File

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package main
import (
"database/sql"
"database/sql/driver"
"encoding/json"
"fmt"
_ "github.com/mattn/go-sqlite3"
"log"
"os"
)
type Tag struct {
Name string `json:"name"`
Country string `json:"country"`
}
func (t *Tag) Scan(value interface{}) error {
return json.Unmarshal([]byte(value.(string)), t)
}
func (t *Tag) Value() (driver.Value, error) {
b, err := json.Marshal(t)
return string(b), err
}
func main() {
os.Remove("./foo.db")
db, err := sql.Open("sqlite3", "./foo.db")
if err != nil {
log.Fatal(err)
}
defer db.Close()
_, err = db.Exec(`create table foo (tag jsonb)`)
if err != nil {
log.Fatal(err)
}
stmt, err := db.Prepare("insert into foo(tag) values(?)")
if err != nil {
log.Fatal(err)
}
defer stmt.Close()
_, err = stmt.Exec(`{"name": "mattn", "country": "japan"}`)
if err != nil {
log.Fatal(err)
}
_, err = stmt.Exec(`{"name": "michael", "country": "usa"}`)
if err != nil {
log.Fatal(err)
}
var country string
err = db.QueryRow("select tag->>'country' from foo where tag->>'name' = 'mattn'").Scan(&country)
if err != nil {
log.Fatal(err)
}
fmt.Println(country)
var tag Tag
err = db.QueryRow("select tag from foo where tag->>'name' = 'mattn'").Scan(&tag)
if err != nil {
log.Fatal(err)
}
fmt.Println(tag.Name)
tag.Country = "日本"
_, err = db.Exec(`update foo set tag = ? where tag->>'name' == 'mattn'`, &tag)
if err != nil {
log.Fatal(err)
}
err = db.QueryRow("select tag->>'country' from foo where tag->>'name' = 'mattn'").Scan(&country)
if err != nil {
log.Fatal(err)
}
fmt.Println(country)
}