golang自訂資料類型查詢與插入postgresql中point資料,golangpostgresql
golang自訂資料類型查詢與插入postgresql中point資料
具體代碼如下:
package mainimport ( "bytes" "database/sql" "database/sql/driver" "fmt" _ "github.com/lib/pq" "strconv" "strings")// 自訂支援類型type Point struct { X float64 `json:"lat"` Y float64 `json:"lng"`}// 實現driver.Valuer介面func (p *Point) Value() (driver.Value, error) { buf := new(bytes.Buffer) fmt.Fprintf(buf, "(%f %f)", p.X, p.Y) return buf.Bytes(), nil}func (p *Point) String() string { return fmt.Sprintf("(%v %v)", p.X, p.Y)}// 實現sql.Scanner介面func (p *Point) Scan(val interface{}) (err error) { if bb, ok := val.([]uint8); ok { tmp := bb[1 : len(bb)-1] coors := strings.Split(string(tmp[:]), ",") if p.X, err = strconv.ParseFloat(coors[0], 64); err != nil { return err } if p.Y, err = strconv.ParseFloat(coors[1], 64); err != nil { return err } } return nil}type Agent struct { Id int `json:"id"` Name string `json:"name"` Code string `json:"code"` CS_NO string `json:"cs_no"` Channel_id int `json:"channel_id"` Address string `json:"address"` Coordinate *Point `json:"point"`}func main() { pgurl := fmt.Sprintf("postgres://%s:%s@%s:%s/%s?sslmode=disable", "postgres", "123456", "localhost", "5432", "people") db, err := sql.Open("postgres", pgurl) if err != nil { panic(fmt.Errorf("串連資料庫出錯:%v", err)) } querySql := `SELECT * FROM t_agent` rows, err := db.Query(querySql) if err != nil { panic(fmt.Errorf("查詢資料出錯:%v", err)) } for rows.Next() { agent := &Agent{Coordinate: &Point{}} err = rows.Scan(&agent.Id, &agent.Name, &agent.Code, &agent.CS_NO, &agent.Channel_id, &agent.Address, agent.Coordinate) fmt.Println(agent, err) } var id int err = db.QueryRow("INSERT INTO t_agent (name, code, cs_no, address, coordinate) VALUES($1,$2,$3,$4,$5) RETURNING id", "test1", "123457", "2", "111", "(12,43)").Scan(&id) fmt.Println("id:", id, "err:", err)}
欄位類型需要支援查詢的scan時,需要實現sql.Scanner介面
欄位類型需要支援插入時,需要實現driver.Valuer介面
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