// Gets the data source of a mapping
public static Wrapper getMappingDataSource(string targetField)
{
//Find the mapping, get the ID of the first source data source
DataTable mapping = MappingEngine.getMappingSource(targetField);
int sourceDataSource = (int)mapping.Rows[0]["SourceDataSource"];
return(getDataSourceWrapper(sourceDataSource));
}
//Query the virtual data source
public static Dictionary <Wrapper, DataTable> query(string query)
{
// Basic implementation
// Get the WHERE clause (this is all we are passing in for now)
List <string> qWhere = query.Split(' ').ToList <string>();
string qWhereField = qWhere[0];
string qWhereOperator = qWhere[1];
string qWhereValue = qWhere[2];
// Find the mapping for the WHERE field
DataTable mapping = MappingEngine.getMappingSource(qWhereField);
// Store the table ID
int whereSourceTable = (int)mapping.Rows[0]["SourceTable"];
// Store the datas source ID
int whereDataSource = (int)mapping.Rows[0]["SourceDataSource"];
// Build a dictionary to hold our results
Dictionary <Wrapper, DataTable> results = new Dictionary <Wrapper, DataTable>();
// We must now loop through all of our data sources and query them for their data
foreach (KeyValuePair <string, Wrapper> dataSource in Program.dataSources)
{
// Store the wrapper so it's easier to reference
Wrapper wrapper = dataSource.Value;
Dictionary <string, Dictionary <string, string> > where = null;
// Check if our mapping table contains this data source's ID
bool contains = mapping.AsEnumerable().Any(row => dataSource.Value.getID() == row.Field <int>("SourceDataSource"));
Console.WriteLine(contains);
// Does our WHERE apply to this data source?
if (dataSource.Value.getID() == whereDataSource)
{
// We need to build a WHERE clause for this data source
// Get the name of the table the WHERE applies to
string whereTableName = MappingEngine.getTableName(whereSourceTable);
// Build the WHERE clause dictionary
where = new Dictionary <string, Dictionary <string, string> >();
// Add the field name to the dictionary
where.Add(qWhereField, new Dictionary <string, string>());
// Add the operator and value to the dictionary for that field
where[qWhereField].Add("operator", qWhereOperator);
where[qWhereField].Add("value", qWhereValue);
}
// Generate a list of columns that we want from this data source, for now we just get them all
// TODO - Only get the columns we actually need (can we do this?)
List <string> columns = new List <string> {
"*"
};
// Generate a list of tables that we want for this data source, for now we just get all the mapped tables
// TODO - Only get tables we actually need (can we do this?)
DataTable mappedTables = MappingEngine.getMappedTables(wrapper);
List <string> tables = mappedTables.AsEnumerable().Select(row => row.Field <string>("Name")).ToList();
results[Program.dataSources[dataSource.Key]] = wrapper.queryWithWhere(columns, tables, where);
}
return(results);
}
