Oracle spatial数据读取

Question

我安装了oracle client在机器上，也安装了oracle odac在本机上，现在连接oracle能读出数据来，但是就是读取空间数据不可以..
SdoGeometry p;
if (reader.IsDBNull(0))
        p = SdoGeometry.Null;
else
       p = (SdoGeometry)reader.GetValue(0);
//这里就报Custom type mapping for 'dataSource='ORCL'//schemaName='MDSYS' typeName='SDO_GEOMETRY'' is not //specified or is invalid.
请问应该怎么办呢？（sample里的类都拷贝过来了）
导进来的数据都是sdo_geometry，类型怎么才能读进来呢？
麻烦大家帮忙～～

Answer 1

"Column Name" "Data Type" "Nullable" "Data Default" "COLUMN ID" "Primary Key" "COMMENTS"
"GID" "NUMBER(38,0)" "No" "" "1" "1" ""
"POLYGON_ID" "NUMBER" "Yes" "" "2" "" ""
"POLYGON_NM" "VARCHAR2(80 BYTE)" "Yes" "" "3" "" ""
"NM_LANGCD" "VARCHAR2(3 BYTE)" "Yes" "" "4" "" ""
"FEAT_TYPE" "VARCHAR2(40 BYTE)" "Yes" "" "5" "" ""
"DETAIL_CTY" "VARCHAR2(1 BYTE)" "Yes" "" "6" "" ""
"FEAT_COD" "NUMBER" "Yes" "" "7" "" ""
"DISP_CLASS" "VARCHAR2(1 BYTE)" "Yes" "" "8" "" ""
"GEOM" "SDO_GEOMETRY" "Yes" "" "9" "" ""就这个sdo_geometry读起来有毛病，剩下的都没问题。vs在执行到p = (SdoGeometry)reader.GetValue(0); 时报错(如顶楼)

Answer 2

会不会跟OracleObjectMappingAttribute有关系？那个应该如何使用呢？

Answer 3

晕，最后查了csdn的帖子，用xml就能读出来
http://topic.csdn.net/t/20050404/22/3908754.html
但是问题是为什么getvalue就不行呢？有人能给解释一下么？