使用 pgx 从 Postgres 扫描 PostGIS 点时，接口 {} 是字符串

Question

我有一个buildings包含coordinate类型列的表的数据库GEOMETRY(POINT, 4326)。带着希望能读懂坐标，我写了如下代码：

    rows, err := db.pool.Query(context.Background(), `select "uuid", "coordinate" from "building"`)

    defer rows.Close()

    for rows.Next() {

        var uuid pgtype.UUID

        var coordinate postgis.Point

        err := rows.Scan(&uuid, &coordinate)

        if err != nil {

            return err

        }

        log.Println("~~~", coordinate.X, coordinate.Y)

    }

然后，我收到以下错误：

2020/08/22 18:32:32 [Recovery] 2020/08/22 - 18:32:32 panic recovered:

POST /get-state HTTP/1.1

Host: localhost:3000

Accept: */*

Accept-Encoding: gzip, deflate, br

Connection: keep-alive

Content-Length: 0

Postman-Token: 4e6f4dc7-9dc4-4cd4-a328-8da2bc86d43d

User-Agent: PostmanRuntime/7.26.3

interface conversion: interface {} is string, not []uint8

/usr/local/Cellar/go/1.14.6/libexec/src/runtime/iface.go:260 (0x100bd11)

    panicdottypeE: panic(&TypeAssertionError{iface, have, want, ""})

/Users/virtumonde/go/pkg/mod/github.com/cridenour/go-postgis@v1.0.0/decode.go:21 (0x10fda31)

    decode: ewkb, err := hex.DecodeString(string(value.([]byte)))

/Users/virtumonde/go/pkg/mod/github.com/cridenour/go-postgis@v1.0.0/point.go:48 (0x10fde58)

    (*Point).Scan: reader, err := decode(value)

/Users/virtumonde/go/pkg/mod/github.com/jackc/pgtype@v1.4.2/pgtype.go:590 (0x120ff39)

    scanPlanSQLScanner.Scan: return scanner.Scan(string(src))

/Users/virtumonde/go/pkg/mod/github.com/jackc/pgx/v4@v4.8.1/rows.go:220 (0x1627b2c)

    (*connRows).Scan: err := rows.scanPlans[i].Scan(ci, fieldDescriptions[i].DataTypeOID, fieldDescriptions[i].Format, values[i], dst)

/Users/virtumonde/go/pkg/mod/github.com/jackc/pgx/v4@v4.8.1/pgxpool/rows.go:70 (0x1634cd4)

    (*poolRows).Scan: err := rows.r.Scan(dest...)

先感谢您。任何的意见都将会有帮助。

Answer 1

import ("github.com/paulmach/orb/encoding/wkb") err := rows.Scan(&uuid, wkb.Scanner(&coordinate))