public object Translate(TranslationContext context, ASTNode node)
{
var result = new SQLModel.TableExpression();
var sqlContext = (SQLTranslationContext)context;
result.TableName = sqlContext.GetExpressionObjectName(String.Format("{0}.{1}", node.GetAttribute<string>("libraryName", sqlContext.ArtifactName), node.GetAttribute<string>("name")));
// If the expression being referenced is scalar, it will be automatically promoted to a query by the expression def translation
// In this case, it must be demoted back to a scalar expression with a subquery access.
if (!(node.ResultType is ListType) && !(node.ResultType is ObjectType))
{
var selectExpression = new SQLModel.SelectExpression();
selectExpression.SelectClause = new SQLModel.SelectClause();
selectExpression.SelectClause.Columns.Add(new SQLModel.ColumnExpression(new SQLModel.QualifiedFieldExpression("value")));
selectExpression.FromClause = new SQLModel.CalculusFromClause(new SQLModel.TableSpecifier(result));
// If the result type is also boolean, the expression will be converted to a 1 or 0, so it must be demoted back to an actual boolean-valued expression
if (DataTypes.Equal(node.ResultType, DataTypes.Boolean))
{
return SQLTranslationUtilities.DemoteBooleanValuedExpression(selectExpression);
}
return selectExpression;
}
return result;
}
public object Translate(TranslationContext context, ASTNode node)
{
var result = new SQLModel.TableExpression();
// TODO: Handle Cardinality
// TODO: Handle whether we are in a FromClause context.
var sqlContext = (SQLTranslationContext)context;
result.TableName = sqlContext.GetExpressionObjectName(String.Format("{0}.{1}", node.GetAttribute<string>("libraryName", sqlContext.ArtifactName), node.GetAttribute<string>("name")));
return result;
}
public object Translate(TranslationContext context, ASTNode node)
{
var requestListType = node.ResultType as ListType;
var requestType = (requestListType == null ? node.ResultType : requestListType.ElementType) as ObjectType;
if (requestType == null)
{
throw new InvalidOperationException(String.Format("Unable to determine request type from source type: '{0}'.", node.ResultType.Name));
}
Model.Expression condition = null;
// Translate Codes
var codes = node.Children.Where(n => n.Name == "codes").FirstOrDefault();
if (codes != null)
{
var codesResult = context.TranslateNode(codes);
// codesResult will be a select statement returning the list of codes
// So the retrieve must include a where condition limiting the code property to the set of codes (same as InValueSet translation)
var codeExpression = SQLTranslationUtilities.ResolvePath(node.GetAttribute<string>("codeProperty"), "T");
var selectExpression = (SQLModel.SelectExpression)codesResult; // This assumes the codes element is a ValueSetRef...
selectExpression.WhereClause.Expression =
new Model.BinaryExpression
(
selectExpression.WhereClause.Expression,
"iAnd",
new Model.BinaryExpression(codeExpression, "iEqual", new SQLModel.QualifiedFieldExpression("Code", "VS"))
);
var codeCondition = new Model.UnaryExpression("iExists", selectExpression);
if (condition != null)
{
condition = new Model.BinaryExpression(condition, "iAnd", codeCondition);
}
else
{
condition = codeCondition;
}
}
// Translate DateRange
var dateRange = node.Children.Where(n => n.Name == "dateRange").FirstOrDefault();
if (dateRange != null)
{
var dateRangeResult = context.TranslateNode(dateRange);
var dateExpression = SQLTranslationUtilities.ResolvePath(node.GetAttribute<string>("dateProperty"), "T");
// dateRangeResult will be an interval-valued expression
// So the retrieve must include a where condition limiting the date range property to the interval (same as In(date, interval) translation)
var dateRangeCondition = new Model.BetweenExpression();
dateRangeCondition.Expression = dateExpression;
// TODO:
//dateRangeCondition.LowerExpression = // dateRangeResult.Low...
//dateRangeCondition.UpperExpression = // dateRangeResult.High...
//if (condition != null)
//{
// condition = new Model.BinaryExpression(condition, "iAnd", dateRangeCondition);
//}
//else
//{
// condition = codeCondition;
//}
}
// For FHIR, there will also potentially need to be profile filters...
// This depends on how the FHIR model is realized within the SQL structures...
var inQueryContext = ((SQLTranslationContext)context).InQueryContext();
// Within a Query Context, a retrieve is part of a FromClause
var tableExpression = new SQLModel.TableExpression(requestType.Name);
if (inQueryContext && (condition == null))
{
return tableExpression;
}
else
{
var selectExpression = new SQLModel.SelectExpression();
selectExpression.SelectClause = new SQLModel.SelectClause();
selectExpression.SelectClause.Distinct = false;
selectExpression.SelectClause.NonProject = true;
selectExpression.FromClause = new SQLModel.CalculusFromClause(new SQLModel.TableSpecifier(tableExpression, "T"));
if (condition != null)
{
selectExpression.WhereClause = new SQLModel.WhereClause();
selectExpression.WhereClause.Expression = condition;
}
return selectExpression;
}
}
