How to get auto generated key when inserting using C#

Question

I inserted a row in a table in oracle 11g as follows:
public void add(Admin admin)
OracleConnection myOracleConnection =
new OracleConnection(connStr);
myOracleConnection.Open();
OracleCommand myOracleCommand = myOracleConnection.CreateCommand();
myOracleCommand.CommandText = "Insert into Admin values(adminSeq.nextVal,:name) returning admin_id into :adminId";
myOracleCommand.Parameters.Clear();
OracleParameter para=new OracleParameter(":adminId",ParameterDirection.Output);
myOracleCommand.Parameters.Add(para);
myOracleCommand.Parameters.Add(":name", admin.Name);
myOracleCommand.ExecuteNonQuery();
admin.AdminId = int.Parse(myOracleCommand.Parameters[":adminId"].Value.ToString());
I found a new row a ADMIN, but I can not get the PK when inserting. the value of "myOracleCommand.Parameters[":adminId"].Value" is always "OUTPUT" , any ideas?
Thank you.
Edited by: user11228816 on 2010-3-1 上午12:17

Answer 1

Does not seem to be an Oracle issue itself. Your approach is correct. E.g.
SQL> create table foo( id number, name varchar2(20) );
Table created.
SQL>
SQL> create sequence foo_id start with 1 increment by 1 nomaxvalue nocycle;
Sequence created.
SQL>
SQL> var id number
SQL> insert into foo values( foo_id.nextval, 'test1') returning id into :id;
1 row created.
SQL>
SQL> print id
        ID
         1
SQL>Check your bind calls. Is the bind name index value for example not perhaps +["adminId"]+ (no bind char marker)?
Also, the binding of the output parameter, i.e.
para=new OracleParameter(":adminId",ParameterDirection.Output);In OCI, when binding, one needs to specify the data type for the bind. When binding strings for example, the length also needs to be specified. This bind seems to be untyped. Yet, you apply a "+ToString()+" method to it when referencing it.. how would the Parameters class know its data type?
Can you do explicit data type binding in C#? If so, try and bind the parameter explicitly as an integer and reference it as an integer when getting its value.