changing variable types of a function of a derived class

[mrclash]

Hello,

I have a class that uses some variables to access a sql database, and I
want to make a derived class that inherits all the methods of this
class, because the derived one will do exactly the same process that
the parent one, but with a postgres database, thus I've got to use
diferent type variables to acces the database.

There's one big function in the class that does all the DB stuff, and I
want to know if there's any way to inherit the function but with only
changing the type of some vars inside this function.

Thanks!

Sergi

 

[Glenn]

Sergi

Is this what your trying to achieve...

abstract class MyBaseClass
{
private IDbConnection _connection;
public virtual IDbConnection Connection
{
get { return _connection; }
set { _connection = value; }
}

public MyBaseClass()
{
Connection = CreateConnection();
}

protected abstract IDbConnection CreateConnection();

public virtual void DoSomeSql()
{
if ( Connection.State != ConnectionState.Open )
{
Connection.Open();
}
using ( IDbCommand command = Connection.CreateCommand() )
{
//If it's parameterised sql you'll need to check what the placeholders
should be for the DB type
//@=sql server, ?=odbc, :=oracle
command.CommandText = "SELECT * FROM T_SOME_DATA";

using ( IDataReader reader = command.ExecuteReader() )
{
while ( reader.Read() )
{
//DoSomething
}
}
}
}
}
class MyOracleVersion : MyBaseClass
{
protected override IDbConnection CreateConnection()
{
return new OracleConnection( "Data Source=emp;user
id=scott;password=tiger" );
}
}
class MySqlServerVersion : MyBaseClass
{
protected override IDbConnection CreateConnection()
{
return new SqlConnection( "How should I know this, I use Oracle" );
}
}

HTH

Glenn

 

[mrclash]

Yeah, this is it! I didn't knew of the IDbConnection interface.

Thanks a lot, and thanks to answer such a newbie question.

Sergi