/// <summary>
/// Creates a new <see cref="AliasNode"/> to wrap the results of a subquery with a different alias
/// </summary>
/// <param name="select">The subquery to wrap the results of</param>
/// <param name="identifier">The alias to use for the subquery</param>
public AliasNode(SelectNode select, Identifier identifier)
{
ColumnSet.AddRange(select.ColumnSet);
Source = select.Source;
Alias = identifier.Value;
// Check for duplicate columns
var duplicateColumn = select.ColumnSet
.GroupBy(col => col.OutputColumn, StringComparer.OrdinalIgnoreCase)
.Where(g => g.Count() > 1)
.FirstOrDefault();
if (duplicateColumn != null)
{
throw new NotSupportedQueryFragmentException($"The column '{duplicateColumn.Key}' was specified multiple times", identifier);
}
}
public override IDataExecutionPlanNode FoldQuery(IDictionary <string, DataSource> dataSources, IQueryExecutionOptions options, IDictionary <string, Type> parameterTypes, IList <OptimizerHint> hints)
{
Source = Source.FoldQuery(dataSources, options, parameterTypes, hints);
Source.Parent = this;
SelectNode.FoldFetchXmlColumns(Source, ColumnSet, dataSources, parameterTypes);
SelectNode.ExpandWildcardColumns(Source, ColumnSet, dataSources, parameterTypes);
if (Source is FetchXmlScan fetchXml)
{
// Check if all the source and output column names match. If so, just change the alias of the source FetchXML
if (ColumnSet.All(col => col.SourceColumn == $"{fetchXml.Alias}.{col.OutputColumn}"))
{
fetchXml.Alias = Alias;
return(fetchXml);
}
}
return(this);
}
