I am new to ODP.net, usually using OracleClient of .NET framework. I try to execute this sql select SEARCH_CONDITION from user_constraints where constraint_type = 'C';
using OracleDataReader. When I try to retrieve all value of SEARCH_CONDITION column, it is empty. I tested with Oracle Sql Developer and it display something there.
I am using Oracle.DataAccess.dll 188.8.131.52 x64 for oracle 11g to access oracle 11g x64.
If you don't have a unique identifier in the SELECT list, you'll hit the following issue described in the doc:
To obtain data beyond the
InitialLONGFetchSize characters or bytes, one of the following must be in the select list:
NULLconstraint defined on it)
To be able to fetch the entire
RAW data without having a primary key column, a
ROWID, or unique columns in the select list, set the size of the
InitialLONGFetchSize property on the
OracleCommand object to equal or greater than the number of characters or bytes needed to be retrieved.
By default, InitialLONGFetchSize is zero. You can increase the property size on the OracleCommand (e.g. cmd.InitialLONGFetchSize = 1000) so that you can fetch the entire value without requiring a primary key or similar.