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Dual-coding for SQL and SQL CE

I'm looking at options to make an application suitable for both MS SQL and SQL CE. The installer will choose whether they are using it single-PC or networked and, if single-PC, I don't want them to have to go through having to install SQL Express.

Problem I'm finding with .NET is that, whilst support for the two DB engines is very good, the SQL and SQLCE objects are different, so everything has to be coded twice, using the two sets of objects.

Can anyone suggest any techniques to build a class that can be told which DB engine to use, but still present a common object to the rest of the application.

Alternatively are there any 3rd party libraries that will do the job?

Jim

Meir Rivkin

can u give an example of a difference?
if you mean something like sqlceCommand and SqlCommand, then you half right.
all u need to duplicate is the DB API layer.
depends on your business, create a shared interface which each of your SQL-type model is implement, so any change should be made in the future won't affect your DB layer.
for instance:

interface IDBLayer
{
DataTable ExecuteProcedure(string procedure, IDictionary<string,string> parameters);
}

public class SqlCEDBLayer:IDBLayer{
DataTable ExecuteProcedure(string constring, string procedure, IDictionary<string,string> parameters){
using (SqlCeConnection connect = new SqlCeConnection(constring))
{
  connect.Open();
SqlCeCommand cmd = connect.CreateCommand();
cmd.CommandText = procedure;
cmd.CommandType = CommandType.StoreProcedure;

foreach (var key in parameters.Keys){
    cmd.Parameters.Add(key);
    cmd.Parameters[key].Value = parameters[key];    
}

SqlCeDataReader rdr = cmd.ExecuteReader();
}
}

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Meir Rivkin

for start create function for running a query with/without parameters, and running stored procedure with/without parameters for SQL and SQLCE.

that should cover most of your business needs.

Member_2_2131373

ASKER

can u give an example of a difference?

For each operation, I have to code for either SQL or SQLCe objects, code snippit as an example below.

        If mySQLType = "SQL" Then
            Using myConnection As New SqlConnection("{connection string}")
                Using myCommand As New SqlCommand("{SQL}", myConnection)
                    Using myRead As SqlDataReader = myCommand.ExecuteReader()
                        'Do something with the result
                    End Using
                End Using
            End Using
        End If

        If mySQLType = "SQLCe" Then
            Using myConnection As New SqlCeConnection("{connection string}")
                Using myCommand As New SqlCeCommand("{SQL}", myConnection)
                    Using myRead As SqlCeDataReader = myCommand.ExecuteReader()
                        'Do something with the result
                    End Using
                End Using
            End Using
        End If

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Problem is that the resultant data (in this example, DataReader) also has to be handled using the relevant object, so pretty much everything that accesses the data has to be dual-coded.

An ideal would be to be able to replace the connection, command, datareader, dataset objects with myConnection, myCommand etc. and have a single type returned irrespective of what actual type is required for physical DB access.

Meir Rivkin

Did u read my prev comment?
This is exactly what iv'e demonstrate in the example code i posted.
If u want ill attach the interfaces and classes involved just to make it more clear 4u

Member_2_2131373

ASKER

Hi sedgwick,

Yes I did read your original post and really don't understand what you are referring to, the code you posted appears to me to be a function that runs a command against the SQLCe objects.

I've obviously missed something fundamental!

ASKER CERTIFIED SOLUTION

Meir Rivkin

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