private void ProcessChainedExpression(ChainedExpression chainedExpression, List <SearchParamTableExpression> tableExpressions, int chainLevel)
{
SearchParamTableExpressionQueryGenerator queryGenerator = chainedExpression.Expression.AcceptVisitor(_searchParamTableExpressionQueryGeneratorFactory, null);
Expression expressionOnTarget = queryGenerator == null ? chainedExpression.Expression : null;
var sqlChainLinkExpression = new SqlChainLinkExpression(
chainedExpression.ResourceTypes,
chainedExpression.ReferenceSearchParameter,
chainedExpression.TargetResourceTypes,
chainedExpression.Reversed,
expressionOnTarget: expressionOnTarget);
tableExpressions.Add(
new SearchParamTableExpression(
ChainLinkQueryGenerator.Instance,
sqlChainLinkExpression,
SearchParamTableExpressionKind.Chain,
chainLevel));
if (chainedExpression.Expression is ChainedExpression nestedChainedExpression)
{
ProcessChainedExpression(nestedChainedExpression, tableExpressions, chainLevel + 1);
}
else if (queryGenerator != null)
{
tableExpressions.Add(
new SearchParamTableExpression(
queryGenerator,
chainedExpression.Expression,
SearchParamTableExpressionKind.Normal,
chainLevel));
}
}
public virtual Expression VisitSqlChainLink(SqlChainLinkExpression sqlChainLinkExpression, TContext context)
{
Expression visitedExpressionOnSource = sqlChainLinkExpression.ExpressionOnSource?.AcceptVisitor(this, context);
Expression visitedExpressionOnTarget = sqlChainLinkExpression.ExpressionOnTarget?.AcceptVisitor(this, context);
if (ReferenceEquals(visitedExpressionOnSource, sqlChainLinkExpression.ExpressionOnSource) &&
ReferenceEquals(visitedExpressionOnTarget, sqlChainLinkExpression.ExpressionOnTarget))
{
return(sqlChainLinkExpression);
}
return(new SqlChainLinkExpression(
sqlChainLinkExpression.ResourceTypes,
sqlChainLinkExpression.ReferenceSearchParameter,
sqlChainLinkExpression.TargetResourceTypes,
sqlChainLinkExpression.Reversed,
visitedExpressionOnSource,
visitedExpressionOnTarget));
}
public override Expression VisitSqlRoot(SqlRootExpression expression, object context)
{
if (expression.SearchParamTableExpressions.Count == 0 || expression.ResourceTableExpressions.Count == 0 ||
expression.SearchParamTableExpressions.All(e => e.Kind == SearchParamTableExpressionKind.Include))
{
// if only Include expressions, the case is handled in IncludeMatchSeedRewriter
return(expression);
}
Expression extractedCommonResourceExpressions = null;
bool containsResourceExpressionFoundOnlyOnResourceTable = false;
for (int i = 0; i < expression.ResourceTableExpressions.Count; i++)
{
SearchParameterExpressionBase currentExpression = expression.ResourceTableExpressions[i];
if (currentExpression is SearchParameterExpression searchParameterExpression)
{
if (searchParameterExpression.Parameter.ColumnLocation().HasFlag(SearchParameterColumnLocation.SearchParamTable))
{
extractedCommonResourceExpressions = extractedCommonResourceExpressions == null ? (Expression)currentExpression : Expression.And(extractedCommonResourceExpressions, currentExpression);
}
else
{
containsResourceExpressionFoundOnlyOnResourceTable = true;
}
}
}
var newTableExpressions = new List <SearchParamTableExpression>(expression.SearchParamTableExpressions.Count);
if (containsResourceExpressionFoundOnlyOnResourceTable)
{
// There is a predicate over _id, which is on the Resource table but not on the search parameter tables.
// So the first table expression should be an "All" expression, where we restrict the resultset to resources with that ID.
newTableExpressions.Add(new SearchParamTableExpression(null, Expression.And(expression.ResourceTableExpressions), SearchParamTableExpressionKind.All));
}
foreach (var tableExpression in expression.SearchParamTableExpressions)
{
if (tableExpression.Kind == SearchParamTableExpressionKind.Include ||
(tableExpression.Kind == SearchParamTableExpressionKind.Normal && tableExpression.ChainLevel > 0) ||
(tableExpression.Kind == SearchParamTableExpressionKind.Chain && tableExpression.ChainLevel > 1))
{
// these predicates do not apply to referenced resources
newTableExpressions.Add(tableExpression);
}
else if (tableExpression.Kind == SearchParamTableExpressionKind.Chain)
{
var sqlChainLinkExpression = (SqlChainLinkExpression)tableExpression.Predicate;
Debug.Assert(sqlChainLinkExpression.ExpressionOnSource == null);
var newChainLinkExpression = new SqlChainLinkExpression(
sqlChainLinkExpression.ResourceTypes,
sqlChainLinkExpression.ReferenceSearchParameter,
sqlChainLinkExpression.TargetResourceTypes,
sqlChainLinkExpression.Reversed,
extractedCommonResourceExpressions,
sqlChainLinkExpression.ExpressionOnTarget);
newTableExpressions.Add(new SearchParamTableExpression(tableExpression.QueryGenerator, newChainLinkExpression, tableExpression.Kind, chainLevel: tableExpression.ChainLevel));
}
else
{
Expression predicate = tableExpression.Predicate == null
? extractedCommonResourceExpressions
: Expression.And(tableExpression.Predicate, extractedCommonResourceExpressions);
newTableExpressions.Add(new SearchParamTableExpression(tableExpression.QueryGenerator, predicate, tableExpression.Kind, tableExpression.ChainLevel));
}
}
return(new SqlRootExpression(newTableExpressions, Array.Empty <SearchParameterExpressionBase>()));
}
public virtual TOutput VisitSqlChainLink(SqlChainLinkExpression sqlChainLinkExpression, TContext context) => default;
