We can use conditional directives in C# that will be executed at the pre-compiler to allow us determine which code will be compiled or not: #if and #endif. To sue them, we need to define a symbol. What do you mean with a symbol? A symbol is like a variable that we will use for this purpose. You can declare one of those using #define or #undef and use it later to add some pre-compiler conditional directives. Let's see an example: [sourcecode language="csharp" wraplines="false"] #define DEVELOPMENT_MODE #undef PRODUCTION_MODE public class OleDB { public static OleDbDataReader ExecuteReader(string cmdText){ #if PRODUCTION_MODE srcDB = "c:\\server\\databases\\bd1.mdb"; #else srcDB = "c:\\bd1.mdb"; #endif } } [/sourcecode] As a mere example, see how we could use a pre-compiler directive to set the database source when we are…

Connecting OleDB in .Net is no different than connecting other database engines, you only need to use a Connection object, a Command object and then make the operations you were planning to do. First of all, you should import the libraries we need for connecting OleDB, so if for connecting to SQL Server you use System.Data.SQLServer, now you will use System.Data.OleDB: [sourcecode language="csharp" wraplines="false"] using System.Data.OleDb; [/sourcecode] Now we'll need a ConnectionString in which the connection details will be set, and which has a different structure for OleDB than for SQL Server. Provider=Microsoft.Jet.OLEDB.4.0;Data Source=DataBaseFileSource;User Id=Admin;Password='' And here we go: [sourcecode language="csharp" wraplines="false"] public static string srcDB = "c:\\development\databases\bd1.mdb"; public static OleDbDataReader ExecuteReader(string cmdText){ OleDbConnection conex = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + srcDB + ";User Id=Admin;Password=''"); conex.Open(); } [/sourcecode] As you can…

Inheritance is the posibility of making a class act as a child of another and inherite its parent methods and properties. So if you have a class called building with the property address and you make another class called flat, you can make flat a child of building and it will inherit the property address without having to declare it. To make flat inherit building you only need to do something like this: [sourcecode language="csharp" wraplines="false"] public class Flat : myClasses.Building { // Here goes the class code } [/sourcecode] Assuming that the class building is inside the namespace MyClasses. But flat will not inherit everything building has, the private methods or properties will not be inherited. Does this means I have to declare everything as public if I want…