C# Array as part of MySQL Select Statement?

Question

Ok heres my scenario - i want to query a local db and store the results of the GUID select query into an array.

i would then like to query the remote server to return a result set which show basically any new records

This is the query but obviously this only works on the same server.

SELECT  *
FROM    remotetable remote
WHERE   NOT EXISTS
        (
        SELECT  1
        FROM    localtable local
        WHERE   local.guid = remote.guid
        ) 

and insert the results of this query into my local db to consolidate it.

so it would be something like

ArrayList myArrayList = new ArrayList();
OdbcConnection local = new OdbcConnection("DSN=local");
local.Open();
OdbcCommand guidSelect = new OdbcCommand("SELECT GUID from localtable",local);
OdbcDataReader DbReader = guidSelect.ExecuteReader();
while (DbReader.Read())
{
String guid = (string)DbReader[0];
myArrayList.Add(guid);
}
local.Close();
OdbcConnection local = new OdbcConnection("DSN=remote");
"SELECT * FROM remotetable remote WHERE NOT EXISTS (SELECT  1 FROM"+ myArrayList() +" local       WHERE   local.guid = remote.guid) 

obviously this will not work as is but it should give a general overview what id like to accomplish

thanks in advance :)

Answer 1

The only way I know how to do this is to actually pass in a table of Guids like this:

string guids = "''" + string.Join("'',''", myArrayList) + "''"; 
string query = string.format("SELECT * FROM remotetable WHERE NOT id IN ({0})", guids);

In my opinion if you are trying to track for new records, you should just add a sequential column and then just grab everything higher than the MAX of that column on the local side.