// The logic here uses unique preserving to support key inference, not the strictly stronger order preserving used for sargability
protected bool IsColumnReferencing(PlanNode node, ref string columnName)
{
StackColumnReferenceNode localNode = node as StackColumnReferenceNode;
if ((localNode != null) && (localNode.Location == 0))
{
columnName = localNode.Identifier;
return(true);
}
else if (node.IsUniquePreserving && (node.NodeCount == 1))
{
return(IsColumnReferencing(node.Nodes[0], ref columnName));
}
else
{
return(false);
}
}
protected void TranslateExpression(CatalogDevicePlan devicePlan, CatalogDevicePlanNode devicePlanNode, PlanNode planNode)
{
InstructionNodeBase instructionNode = planNode as InstructionNodeBase;
if (instructionNode != null)
{
if ((instructionNode.DataType != null) && (instructionNode.Operator != null))
{
switch (Schema.Object.Unqualify(instructionNode.Operator.OperatorName))
{
case Instructions.And:
case Instructions.Equal:
case Instructions.NotEqual:
case Instructions.Greater:
case Instructions.InclusiveGreater:
case Instructions.Less:
case Instructions.InclusiveLess:
case Instructions.Like:
TranslateExpression(devicePlan, devicePlanNode, instructionNode.Nodes[0]);
devicePlanNode.WhereCondition.AppendFormat(" {0} ", GetInstructionKeyword(Schema.Object.Unqualify(instructionNode.Operator.OperatorName)));
TranslateExpression(devicePlan, devicePlanNode, instructionNode.Nodes[1]);
return;
case "ReadValue": TranslateExpression(devicePlan, devicePlanNode, instructionNode.Nodes[0]); return;
default: devicePlan.IsSupported = false; return;
}
}
}
ValueNode valueNode = planNode as ValueNode;
if (valueNode != null)
{
TranslateScalarParameter(devicePlan, devicePlanNode, planNode);
return;
}
StackReferenceNode stackReferenceNode = planNode as StackReferenceNode;
if (stackReferenceNode != null)
{
TranslateScalarParameter(devicePlan, devicePlanNode, new StackReferenceNode(stackReferenceNode.DataType, stackReferenceNode.Location - 1));
return;
}
StackColumnReferenceNode stackColumnReferenceNode = planNode as StackColumnReferenceNode;
if (stackColumnReferenceNode != null)
{
if (stackColumnReferenceNode.Location == 0)
{
if (devicePlan.TableContext != null)
{
devicePlanNode.WhereCondition.Append(Schema.Object.EnsureUnrooted(MetaData.GetTag(devicePlan.TableContext.Columns[stackColumnReferenceNode.Identifier].MetaData, "Storage.Name", stackColumnReferenceNode.Identifier)));
}
else
{
devicePlanNode.WhereCondition.Append(Schema.Object.EnsureUnrooted(stackColumnReferenceNode.Identifier));
}
}
else
{
TranslateScalarParameter(devicePlan, devicePlanNode, new StackColumnReferenceNode(stackColumnReferenceNode.Identifier, stackColumnReferenceNode.DataType, stackColumnReferenceNode.Location - 1));
}
return;
}
devicePlan.IsSupported = false;
}
