Documentation
¶
Overview ¶
Package ewkb 实现了 扩展的著名二进制编码和解码。 See https://github.com/postgis/postgis/blob/2.1.0/doc/ZMSgeoms.txt.
如果你正在将几何图形编码成 EWKB ,并存进 PostgreSQL/PostGIS。你必须设置 binary_parameters=yes，在 你向 sql.Open传递的数据资源中
Example (Scan) ¶
type City struct {
Name string
Location ewkb.Point
}
db, mock, err := sqlmock.New()
if err != nil {
log.Fatal(err)
}
defer db.Close()
mock.ExpectQuery(`SELECT name, ST_AsEWKB\(location\) FROM cities WHERE name = \?;`).
WithArgs("London").
WillReturnRows(
sqlmock.NewRows([]string{"name", "location"}).
AddRow("London", geomtest.MustHexDecode("0101000020e610000052b81e85eb51c03f45f0bf95ecc04940")),
)
var c City
if err := db.QueryRow(`SELECT name, ST_AsEWKB(location) FROM cities WHERE name = ?;`, "London").Scan(&c.Name, &c.Location); err != nil {
log.Fatal(err)
}
fmt.Printf("Longitude: %v\n", c.Location.X())
fmt.Printf("Latitude: %v\n", c.Location.Y())
fmt.Printf("SRID: %v\n", c.Location.SRID())
Output: Longitude: 0.1275 Latitude: 51.50722 SRID: 4326
Example (Value) ¶
type City struct {
Name string
Location ewkb.Point
}
db, mock, err := sqlmock.New()
if err != nil {
log.Fatal(err)
}
defer db.Close()
mock.ExpectExec(`INSERT INTO cities \(name, location\) VALUES \(\?, \?\);`).
WithArgs("London", geomtest.MustHexDecode("0101000020e610000052b81e85eb51c03f45f0bf95ecc04940")).
WillReturnResult(sqlmock.NewResult(1, 1))
c := City{
Name: "London",
Location: ewkb.Point{geom.NewPoint(geom.XY).MustSetCoords(geom.Coord{0.1275, 51.50722}).SetSRID(4326)},
}
result, err := db.Exec(`INSERT INTO cities (name, location) VALUES (?, ?);`, c.Name, &c.Location)
if err != nil {
log.Fatal(err)
}
rowsAffected, _ := result.RowsAffected()
fmt.Printf("%d rows affected", rowsAffected)
Output: 1 rows affected
Index ¶
- Variables
- func Marshal(g geom.T, byteOrder binary.ByteOrder) ([]byte, error)
- func Read(r io.Reader) (geom.T, error)
- func Unmarshal(data []byte) (geom.T, error)
- func Write(w io.Writer, byteOrder binary.ByteOrder, g geom.T) error
- type ErrExpectedByteSlice
- type GeometryCollection
- type LineString
- type MultiLineString
- type MultiPoint
- type MultiPolygon
- type Point
- type Polygon
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( // XDR is big endian. XDR = wkbcommon.XDR // NDR is little endian. NDR = wkbcommon.NDR )
Functions ¶
Types ¶
type ErrExpectedByteSlice ¶
type ErrExpectedByteSlice struct {
Value interface{}
}
ErrExpectedByteSlice 将被返回,当 []byte 是正确的.
func (ErrExpectedByteSlice) Error ¶
func (e ErrExpectedByteSlice) Error() string
type GeometryCollection ¶
type GeometryCollection struct {
*geom.GeometryCollection
}
A GeometryCollection 是 WEKB 编码的几何图形集合，它实现了sql.Scanner 和 driver.Value 接口
func (*GeometryCollection) Scan ¶
func (gc *GeometryCollection) Scan(src interface{}) error
Scan scans from a []byte.
func (*GeometryCollection) Valid ¶
func (gc *GeometryCollection) Valid() bool
Valid returns true if gc has a value.
type LineString ¶
type LineString struct {
*geom.LineString
}
A LineString 是 EWKB编码的单线，它实现了sql.Scanner 和 driver.Value 接口
func (*LineString) Scan ¶
func (ls *LineString) Scan(src interface{}) error
Scan scans from a []byte.
type MultiLineString ¶
type MultiLineString struct {
*geom.MultiLineString
}
A MultiLineString 是 WEKB 编码的多线集合，它实现了sql.Scanner 和 driver.Value 接口
func (*MultiLineString) Scan ¶
func (mls *MultiLineString) Scan(src interface{}) error
Scan scans from a []byte.
func (*MultiLineString) Valid ¶
func (mls *MultiLineString) Valid() bool
Valid returns true if mls has a value.
type MultiPoint ¶
type MultiPoint struct {
*geom.MultiPoint
}
A MultiPoint 是 EWKB编码的多点集合，它实现了sql.Scanner 和 driver.Value 接口
func (*MultiPoint) Scan ¶
func (mp *MultiPoint) Scan(src interface{}) error
Scan scans from a []byte.
type MultiPolygon ¶
type MultiPolygon struct {
*geom.MultiPolygon
}
A MultiPolygon 是 WEKB 编码的多边行集合对象，它实现了sql.Scanner 和 driver.Value 接口
func (*MultiPolygon) Scan ¶
func (mp *MultiPolygon) Scan(src interface{}) error
Scan scans from a []byte.
func (*MultiPolygon) Valid ¶
func (mp *MultiPolygon) Valid() bool
Valid returns true if mp has a value.
type Point ¶
type Point struct {
*geom.Point
}
A Point 是 EWKB编码的 点，它实现了sql.Scanner 和 driver.Value 接口
Source Files