public StarModel Refine(StarModel starModel)
{
FactTable fact = starModel.FactTable;
// Create new dimension
List <StarColumn> stringColumns = new List <StarColumn>();
if (fact.Columns.Count(x => x.DataType.IsString()) == 0)
{
return(starModel);
}
var surrogateKey = new StarColumn(1, "SurKey", new DataType(OleDbType.Integer), StarColumnType.Key | StarColumnType.SurrogateKey);
stringColumns.Add(surrogateKey);
var junkColumns = fact.Columns.Where(x => x.DataType.IsString()).Select(c => new JunkColumn(c));
stringColumns.AddRange(junkColumns);
JunkDimension dimension = new JunkDimension($"Junk_{fact.Name}", stringColumns, fact.TableReference);
surrogateKey.TableRef = dimension;
dimension.Constraints.PrimaryKey.Columns.Add(surrogateKey);
dimension.Constraints.Uniques.Add(new Unique(stringColumns));
// Fact relation to new dimension
var foreignColumn = new StarColumn(0, $"{dimension.Name}_Key", new DataType(OleDbType.Integer), StarColumnType.Key);
foreignColumn.TableRef = fact;
fact.Columns.Add(foreignColumn);
// Remove string columns from fact table
starModel.FactTable.Columns.RemoveAll(c => c.DataType.IsString());
StarRelation r = new StarRelation(dimension, starModel.FactTable, new List <StarColumn>()
{
surrogateKey
}, new List <StarColumn>()
{
foreignColumn
}, Cardinality.ManyToOne);
fact.Relations.Add(r);
dimension.Relations.Add(r);
starModel.Dimensions.Add(dimension);
return(starModel);
}
public override StarModel TranslateModel(StarModel starModel)
{
//All fact tables across all star models
FactTable factTable = starModel.FactTable;
List <Dimension> temporaryDimensions = starModel.Dimensions;
// Case 1, if dimensions have been found, simply flatten them
// Case 2, if dimensions have *not* been found, find all connected tables to the fact table and flatten them.
// Case 2
if (temporaryDimensions.Count == 0)
{
List <Table> tables =
factTable.TableReference.Relations
.Where(x => factTable.TableReference == x.LinkTable && x.Cardinality == Cardinality.ManyToOne &&
x.AnchorTable != factTable.TableReference)
.Select(x => x.AnchorTable)
.ToList();
temporaryDimensions = tables.Select(table => new Dimension(table)).ToList();
}
// Case 1
foreach (var dim in temporaryDimensions)
{
var tableRef = dim.TableReference;
var newColumns = Flatten(tableRef, new List <Table>()
{
tableRef
});
dim.Columns.AddRange(newColumns);
dim.Columns.ForEach(x => x.TableRef = dim);
}
factTable.Relations.Clear();
// Add relations from fact table to all dimensions
foreach (var dimension in temporaryDimensions)
{
var starRelation = new StarRelation(dimension, factTable, Cardinality.ManyToOne);
factTable.Relations.Add(starRelation);
dimension.Relations.Add(starRelation);
}
starModel.Dimensions.AddRange(temporaryDimensions);
return(starModel);
}
public StarModel Refine(StarModel starModel)
{
var factTable = starModel.FactTable;
// If any date/time dimension already exists
if (starModel.Dimensions.Any(d => d.Name.Contains("time") || d.Name.Contains("date")))
{
return(starModel);
}
// Create date and time dimension for model. These are also used for roleplaying
DateDimension actualDateDimension = CreateDateDimension();
TimeDimension actualTimeDimension = CreateTimeDimension();
// These can either be the actual dimension or roleplaying dimensions
DateDimension dateDimension = null;
TimeDimension timeDimension = null;
// Add a date and/or time dimension to all columns that can express date or time
foreach (var temporalColumn in factTable.Columns.Where(c => c.DataType.IsTemporal()).ToList())
{
// If date, only add date dimension, likewise with time. If a date/time dimension is already in use,
// then use that for roleplaying
switch (temporalColumn.DataType.Type)
{
case OleDbType.DBTime:
timeDimension = timeDimension != null ? new TimeDimension(actualTimeDimension) : actualTimeDimension;
break;
case OleDbType.Date:
case OleDbType.DBDate:
dateDimension = dateDimension != null ? new DateDimension(actualDateDimension) : actualDateDimension;
break;
case OleDbType.DBTimeStamp:
dateDimension = dateDimension != null ? new DateDimension(actualDateDimension) : actualDateDimension;
timeDimension = timeDimension != null ? new TimeDimension(actualTimeDimension) : actualTimeDimension;
break;
}
// If time dimension is set, then add it to the model and add a relation
if (timeDimension != null)
{
starModel.Dimensions.Add(timeDimension);
var timeForeignKey = new StarColumn(factTable.Columns.Count + 1, $"{temporalColumn.Name}_Time_Key", new DataType(OleDbType.Integer), StarColumnType.Key);
timeForeignKey.ColumnRef = temporalColumn.ColumnRef;
var relation = new StarRelation(timeDimension, factTable, new List <StarColumn> {
timeDimension.Columns[0]
}, new List <StarColumn> {
timeForeignKey
}, Cardinality.ManyToOne);
factTable.Relations.Add(relation);
timeDimension.Relations.Add(relation);
factTable.Columns.Add(timeForeignKey);
factTable.Constraints.PrimaryKey.Columns.Add(timeForeignKey);
}
// If date dimension is set, then add it to the model and add a relation
if (dateDimension != null)
{
starModel.Dimensions.Add(dateDimension);
var dateForeignKey = new StarColumn(factTable.Columns.Count + 1, $"{temporalColumn.Name}_Date_Key", new DataType(OleDbType.Integer), StarColumnType.Key);
dateForeignKey.ColumnRef = temporalColumn.ColumnRef;
var relation = new StarRelation(dateDimension, factTable, new List <StarColumn> {
dateDimension.Columns[0]
}, new List <StarColumn> {
dateForeignKey
}, Cardinality.ManyToOne);
factTable.Relations.Add(relation);
dateDimension.Relations.Add(relation);
factTable.Columns.Add(dateForeignKey);
factTable.Constraints.PrimaryKey.Columns.Add(dateForeignKey);
}
temporalColumn.ColumnType = StarColumnType.DescriptiveMeasure;
// Cleanup
factTable.Columns.Remove(temporalColumn);
}
return(starModel);
}
