/// <summary>
/// Order BY clause with prefSQL keywords (SUMRANK or BESTRANK)
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public override PrefSQLModel VisitOrderBySpecial(PrefSQLParser.OrderBySpecialContext context)
{
SQLCommon.Ordering ordering = SQLCommon.Ordering.AsIs;
if (context.op.Type == PrefSQLParser.K_SUMRANK)
{
ordering = SQLCommon.Ordering.RankingSummarize;
}
else if (context.op.Type == PrefSQLParser.K_BESTRANK)
{
ordering = SQLCommon.Ordering.RankingBestOf;
}
Model.Ordering = ordering;
return(base.VisitOrderBySpecial(context));
}
/// <summary>
/// Create the ORDER BY-Clause from the preference model
/// </summary>
/// <param name="model"></param>
/// <param name="type"></param>
/// <returns></returns>
public string GetSortClause(PrefSQLModel model, SQLCommon.Ordering type)
{
string strSQL = "";
switch (type)
{
case SQLCommon.Ordering.AttributePosition:
strSQL = GetSortAttributePositionClause(model);
break;
case SQLCommon.Ordering.RankingSummarize:
strSQL = GetSortRankingSumClause(model);
break;
case SQLCommon.Ordering.RankingBestOf:
strSQL = GetSortRankingBestOfClause(model);
break;
case SQLCommon.Ordering.AsIs:
strSQL = ""; //Return no ORDER BY Clause
break;
case SQLCommon.Ordering.Random:
strSQL = GetSortRandomClause();
break;
case SQLCommon.Ordering.EntropyFunction:
{
strSQL = GetSortEntropyValue(model);
break;
}
}
if (strSQL.Length > 0)
{
strSQL = " ORDER BY " + strSQL;
}
return(strSQL);
}
