sql server Geometry 類型操作 筆記

sqlGeometry 類型為sql server 2008之后的版本 新加的一種CLR擴展數據類型，為廣大sql server開發人員存儲幾何類型及空間運算提供極大的便利，下面說明geometry類型的具體操作

示例SQL語句代碼

IF OBJECT_ID ( 'dbo.SpatialTable', 'U' ) IS NOT NULL 
DROP TABLE dbo.SpatialTable;
GO

CREATE TABLE SpatialTable 
( id int IDENTITY (1,1),
GeomCol1 geometry, 
GeomCol2 AS GeomCol1.STAsText() );
GO

 

 

INSERT INTO SpatialTable (GeomCol1)
VALUES (geometry::STGeomFromText('LINESTRING (100 100, 20 180, 180 180)', 0));

INSERT INTO SpatialTable (GeomCol1)
VALUES (geometry::STGeomFromText('POLYGON ((0 0, 150 0, 150 150, 0 150, 0 0))', 0));
GO

INSERT INTO SpatialTable (GeomCol1)
VALUES(geometry::STGeomFromText('LINESTRING (116.387112 39.920977,116.385243 39.913063,116.394226 39.917988,116.401772 39.921364,116.41248 39.927893,116.387112 39.920977)', 4326))

　　

 

幾何類型操作

Database db = DatabaseFactory.CreateDatabase();
DbCommand dbCmd = db.GetSqlStringCommand("SELECT GeomCol1 FROM SpatialTable WHERE id=4");
using (IDataReader reader = db.ExecuteReader(dbCmd))
{
if (reader.Read())
{
SqlGeometry o = reader[0] as SqlGeometry;

}
}

SqlGeometry geo = SqlGeometry.Parse("POLYGON ((0 0, 150 0, 150 150, 0 150, 0 0))");
//DataSet ds = db.ExecuteDataSet(dbCmd);

//SqlGeometry geo = ds.Tables[0].Rows[0][1] as SqlGeometry;

//SqlDouble area = geo.STArea();

dbCmd = db.GetSqlStringCommand(@"INSERT INTO SpatialTable (GeomCol1) values(@p)");

//構建多邊形
SqlGeometryBuilder sb = new SqlGeometryBuilder();
sb.SetSrid(4326);
sb.BeginGeometry(OpenGisGeometryType.Polygon);
sb.BeginFigure(0, 0);
sb.AddLine(150, 0);
sb.AddLine(150, 150);
sb.AddLine(0, 150);
sb.AddLine(0, 0);
sb.EndFigure();
sb.EndGeometry();

dbCmd = db.GetSqlStringCommand(string.Format("INSERT INTO SpatialTable (GeomCol1) values(geometry::STGeomFromText('{0}', {1}))"
, sb.ConstructedGeometry.ToString(), 4326));
//db.AddInParameter(dbCmd, "@p", DbType.Binary, sb.ConstructedGeometry.STAsBinary().Buffer);

int cnt = db.ExecuteNonQuery(dbCmd);

 

　　

 

 

數據庫對數據進行過濾操作

SELECT c_geomCol.MakeValid().STCentroid().STAsText() FROM t_green_point
WHERE c_geomCol IS NOT NULL
--AND c_geomCol2<>'POLYGON EMPTY'
AND c_geomCol.STIsValid()=1

 

 

通過這個sql獲得系統的坐標系（Sql server中）：Select * from sys.spatial_reference_systems

 

 

//MultiPolygon 多個多邊形結合處理

SqlGeometryBuilder sb = new SqlGeometryBuilder(); //構造多個多邊形實例
sb.SetSrid(0);
sb.BeginGeometry(OpenGisGeometryType.MultiPolygon);

sb.BeginGeometry(OpenGisGeometryType.Polygon); //構造第一個多邊形
sb.BeginFigure(1, 1);
sb.AddLine(1, -1);
sb.AddLine(-1,-1);
sb.AddLine(-1,1);
sb.AddLine(1,1);
sb.EndFigure();
sb.EndGeometry();

sb.BeginGeometry(OpenGisGeometryType.Polygon); //構造第二個多邊形
sb.BeginFigure(1,1);
sb.AddLine(3,1);
sb.AddLine(3,3);
sb.AddLine(1,3);
sb.AddLine(1,1);
sb.EndFigure();
sb.EndGeometry();

sb.BeginGeometry(OpenGisGeometryType.Polygon); //構造第N個多邊形
sb.BeginFigure(4,4);
sb.AddLine(6,4);
sb.AddLine(6,6);
sb.AddLine(4,6);
sb.AddLine(4,4);
sb.EndFigure();
sb.EndGeometry();

sb.EndGeometry();

geo = sb.ConstructedGeometry;

//下面是解析代碼
int numGeometries = geo.STNumGeometries().Value; //有多少個多邊形

SqlGeometry geoN = null;

for (int i = 1; i <= numGeometries; i++)
{
geoN = geo.STGeometryN(i);//第幾個多邊形
for (int j = 1; j <= geoN.STNumPoints(); j++) //轉到百度地圖多邊形最后一個點可以去掉
{
point = geoN.STPointN(i);
Console.WriteLine("第{0}個多邊形，第{1}點,X={2},Y={3}", i, j, point.STX.Value, point.STY);
}

}

 

　　

 輸出結果：

 

 

參數化的SQL語句傳值

   DbCommand dbCmd = db.GetSqlStringCommand(@"INSERT INTO SpatialTable (GeomCol1) values(@p)");

  db.AddInParameter(dbCmd, "@p", DbType.Binary, sb.ConstructedGeometry.Serialize());

  int cnt = db.ExecuteNonQuery(dbCmd);

 

　　

判斷多邊形是否相交

 

DECLARE @bigGeo geometry= 'POLYGON((0 0, 3 0, 3 3, 0 3,0 0))'; 
DECLARE @smallGeo geometry='POLYGON((1 1 ,2 1,2 2,1 2,1 1))'; 
DECLARE @midGeo geometry='POLYGON((0 0, 1.5 0, 1.5 1.5, 0 1.5,0 0))'; 
DECLARE @Geo3 geometry='POLYGON((2 2, 3 2,3 3,2 3,2 2))'; 


SELECT @bigGeo.STIntersection(@smallGeo).STAsText()


SELECT @midGeo.STIntersection(@smallGeo).STIsEmpty()

SELECT @midGeo.STIntersection(@Geo3).STIsEmpty()

如果相交則結果不為空

 

 

參考資料：

  https://msdn.microsoft.com/zh-cn/library/bb964711.aspx   

  https://msdn.microsoft.com/zh-cn/library/ee642119.aspx

  https://msdn.microsoft.com/zh-cn/library/microsoft.sqlserver.types.sqlgeometrybuilder(v=sql.120).aspx

 

       

         空間數據類型相關Transact-SQL

          https://msdn.microsoft.com/zh-cn/library/cc280487(v=sql.120).aspx