string BuildGroupBy(Query query, ISqlExpressionBuilder sqlBuilder)
{
if (query.Fields == null || query.Fields.Length == 0 || !query.Fields.Any(isAggregateField))
{
return(null);
}
var groupByCols = new StringBuilder();
foreach (var qField in query.Fields)
{
if (!isAggregateField(qField))
{
var f = qField;
if (FieldMapping != null && FieldMapping.ContainsKey(f.Name))
{
f = new QField(f.Name, FieldMapping[f.Name]);
}
if (groupByCols.Length > 0)
{
groupByCols.Append(',');
}
groupByCols.Append(sqlBuilder.BuildValue((IQueryValue)f));
}
}
return(groupByCols.Length > 0 ? groupByCols.ToString() : null);
bool isAggregateField(QField fld)
{
if (fld is QAggregateField)
{
return(true);
}
// special handling for count(*)
if (fld.Expression != null && fld.Expression.ToLower() == QField.Count.Expression)
{
return(true);
}
return(false);
}
}
string BuildSelectColumns(Query query, ISqlExpressionBuilder sqlBuilder)
{
// Compose fields part
if (query.Fields == null || query.Fields.Length == 0)
{
return(ApplyFieldMapping("*"));
}
var columns = new StringBuilder();
foreach (var qField in query.Fields)
{
var f = qField;
if (FieldMapping != null && FieldMapping.ContainsKey(f.Name))
{
f = new QField(f.Name, FieldMapping[f.Name]);
}
var fld = sqlBuilder.BuildValue((IQueryValue)f);
if (fld != f.Name && f.Expression != null) // use "as" only for expression-fields
// special handling for 'count(*)' mapping
{
if (f.Expression.ToLower() == "count(*)")
{
fld = ApplyFieldMapping("count(*)");
}
fld = String.IsNullOrEmpty(f.Name) ? fld : String.Format("{0} as {1}", fld, sqlBuilder.BuildValue((QField)f.Name));
}
if (columns.Length > 0)
{
columns.Append(',');
}
columns.Append(fld);
}
return(columns.ToString());
}