private SqlSelect BuildUnionQuery(IndexInfo index)
{
ISqlQueryExpression result = null;
var baseQueries = index.UnderlyingIndexes.Select(BuildProviderQuery).ToList();
foreach (var select in baseQueries)
{
result = result == null
? (ISqlQueryExpression)select
: result.Union(select);
}
var unionRef = SqlDml.QueryRef(result);
var query = SqlDml.Select(unionRef);
query.Columns.AddRange(unionRef.Columns);
return(query);
}
