QODBC, QSqlQuery, out parameters of stored procedures

[rusvid]

I use the driver QODBC to connect to the database MS SQL Server. I execute a stored procedure. The stored procedure returns values through parameters. stored procedure always returns the empty string for parameters of type QString.
For example:

alter procedure [dbo].[fp_test]
( @Name varchar(50),
  @Value varchar(50) out,
  @Number int out
 )
as
set nocount on
Select @Value='test', @Number=123

alter procedure [dbo].[fp_test]
( @Name varchar(50),
  @Value varchar(50) out,
  @Number int out
 )
as
set nocount on
Select @Value='test', @Number=123

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QSqlQuery query;
//query.setForwardOnly(true);
query.prepare("{CALL fp_test(?,?,?)}");
query.addBindValue(strName);
query.addBindValue(strValue,QSql::Out);
query.addBindValue(n,QSql::Out);
if (!query.exec())
{ QMessageBox::information(0, QObject::tr("Error"), "Error");
   return 1;
}
 
strValue = query.boundValue(1).toString(); // "" :confused: - must be "test"
n = query.boundValue(2).toInt();;              // 123 - ok

QSqlQuery query;
//query.setForwardOnly(true);
query.prepare("{CALL fp_test(?,?,?)}");
query.addBindValue(strName);
query.addBindValue(strValue,QSql::Out);
query.addBindValue(n,QSql::Out);
if (!query.exec())
{ QMessageBox::information(0, QObject::tr("Error"), "Error");
   return 1;
}

strValue = query.boundValue(1).toString(); // "" :confused: - must be "test"
n = query.boundValue(2).toInt();;              // 123 - ok

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