ORACLE这弱智错误把人气疯了！ - Oracle / 开发

写了个最简单的存储过程，就是按照地区从学生表里取出学号和姓名，如下：
create or replace PROCEDURE SP_SelectStudentByDq (dq_id IN VARCHAR2, CUR OUT SELECT_PACKAGE.RET_CUR)
AS
BEGIN
OPEN CUR FOR
select code, name from students where dq = dq_id;
END;

然后客户端C#调用
OracleCommand cmdToExecute = new OracleCommand();
cmdToExecute.CommandText = "SP_SelectStudentByDq";
cmdToExecute.CommandType = CommandType.StoredProcedure;
cmdToExecute.Connection = _mainConnection;
DataTable retTable = new DataTable();
OracleDataAdapter oAdapter = new OracleDataAdapter(cmdToExecute);

cmdToExecute.Parameters.Add(new OracleParameter("dq_id", OracleType.VarChar, 20, ParameterDirection.Input, false, 0, 0, "", DataRowVersion.Proposed, _dq));
cmdToExecute.Parameters.Add(new OracleParameter("CUR", OracleType.Cursor, 0, ParameterDirection.Output, false, 0, 0, "", DataRowVersion.Proposed, 0));

_mainConnection.Open();
oAdapter.Fill(retTable);
return retTable;
_mainConnection.Close();

传入地区参数，比如"11000000"（北京）、"21000000"（辽宁）怎么都取不出来值。
但是在存储过程里面写死：select code, name from students where dq = ‘21000000';马上就取出数据了。

或者，将存储过程修改为：select code, name from students where dq like dq_id;
传入"21000000%"或"11000000%"等也能对。