c＃Dapper中的dbms_output.Put_line

Question

I need return a variable oracle to C#, however I use Dapper, so exist a way to receive a output by dapper?

I tried like this

ORACLE    ...
            ,NULL                                                               /*CLIENTE_GRUPO_CPF*/
            ,'P'                                                                /*LOTE_PRODUCAO_PEDIDO*/
            ,'N'                                                                /*LIBERACAO_COMERCIAL*/
            ,NULL                                                               /*USUARIO_LIB_COMERCIAL*/
            ,NULL                                                               /*DATA_LIB_COMERCIAL*/
            ,NULL                                                               /*HORA_LIB_COMERCIAL*/
            ,'L'                                                                );
    COMMIT;
    dbms_output.put_line(var_zi_controle_id);
    END ;


C#  
var id = conn.QueryFirstOrDefault<int>(sql);

but this way the answer is 0.

Answer 1

Using dbms_output.put_line(var_zi_controle_id); to Output a variable is incorrect, this would not work with programming languages / database driver like ODP.Net, this is for console printing and verification.

Dapper consist of set of extension methods which extends IDbConnection interface of ADO.Net, internally for Oracle you would fill in ODP.Net - OracleConnection object, now when you check the ODP.Net guide for calling any of the PL SQL Stored procedures, you have following options:

1. Bind a Output or Return parameter and fill the parameter in the PL SQL procedure. Using Dapper, you need DynamicParameter for binding parameters beside Input like Output / Return
2. Other option is way you are currently trying, you are expecting Select statement to return the value as integer, so what you need is Select var_zi_controle_id in the procedure, which will come as a QueryResult, but still you would need a Type T, which contains an integer value, here you would get a Type / class with one integer property var_zi_controle_id . Query<T> though returns IEnumerable<T>

My Preferred way would be adding the Output parameter, assign in the Stored Procedureand retrieve value, check the links underneath for good reference. A simple example would be:

 var dynamicParameters = new DynamicParameters();
 dynamicParameters.Add("var_zi_controle_id",0,DbType.Int32,ParameterDirection.Output)

Parameter Direction options InputOutput and ReturnValue can also be used, but ReturnValue needs explicit return value from the procedure

// Execute the Stored Procedure

conn.Execute(@"ProcedureName", dynamicParameters, commandType: CommandType.StoredProcedure);

// Fetch O/p Parameter Value from dynamicParameters

var id = dynamicParameters.Get<int>("var_zi_controle_id");

Its important that Output parameter var_zi_controle_id , which bind to the stored procedure is set, before the call returns, for value to be fetched

OracleCommand SQL Parameters Binding

https://docs.oracle.com/database/121/ODPNT/OracleCommandClass.htm#ODPNT458

https://docs.oracle.com/cd/E11882_01/win.112/e23174/OracleParameterClass.htm#ODPNT1722