protected override IEnumerable <Entity> ExecuteInternal(IDictionary <string, DataSource> dataSources, IQueryExecutionOptions options, IDictionary <string, Type> parameterTypes, IDictionary <string, object> parameterValues)
{
var leftSchema = LeftSource.GetSchema(dataSources, parameterTypes);
var innerParameterTypes = GetInnerParameterTypes(leftSchema, parameterTypes);
if (OuterReferences != null)
{
if (parameterTypes == null)
{
innerParameterTypes = new Dictionary <string, Type>();
}
else
{
innerParameterTypes = new Dictionary <string, Type>(parameterTypes);
}
foreach (var kvp in OuterReferences)
{
innerParameterTypes[kvp.Value] = leftSchema.Schema[kvp.Key];
}
}
var rightSchema = RightSource.GetSchema(dataSources, innerParameterTypes);
var mergedSchema = GetSchema(dataSources, parameterTypes, true);
var joinCondition = JoinCondition?.Compile(mergedSchema, parameterTypes);
foreach (var left in LeftSource.Execute(dataSources, options, parameterTypes, parameterValues))
{
var innerParameters = parameterValues;
if (OuterReferences != null)
{
if (parameterValues == null)
{
innerParameters = new Dictionary <string, object>();
}
else
{
innerParameters = new Dictionary <string, object>(parameterValues);
}
foreach (var kvp in OuterReferences)
{
left.Attributes.TryGetValue(kvp.Key, out var outerValue);
innerParameters[kvp.Value] = outerValue;
}
}
var hasRight = false;
foreach (var right in RightSource.Execute(dataSources, options, innerParameterTypes, innerParameters))
{
var merged = Merge(left, leftSchema, right, rightSchema);
if (joinCondition == null || joinCondition(merged, parameterValues, options))
{
yield return(merged);
}
hasRight = true;
if (SemiJoin)
{
break;
}
}
if (!hasRight && JoinType == QualifiedJoinType.LeftOuter)
{
yield return(Merge(left, leftSchema, null, rightSchema));
}
}
}
