public override TResult ExecuteScalar <TResult>(Object dataContext, OeQueryContext queryContext)
{
Cache.OeCacheContext cacheContext = queryContext.CreateCacheContext();
Cache.OeQueryCacheItem?queryCacheItem = base.QueryCache.GetQuery(cacheContext);
InMemoryScalarExecutor <TResult> executor;
IReadOnlyList <Cache.OeQueryCacheDbParameterValue> parameterValues;
if (queryCacheItem == null)
{
var variableVisitor = new InMemoryConstantToVariableVisitor();
Expression expression = queryContext.CreateExpression(out IReadOnlyDictionary <ConstantExpression, ConstantNode> constants);
expression = variableVisitor.Translate(expression, constants);
expression = new OeSingleNavigationVisitor(queryContext.EdmModel).Visit(expression);
expression = new OeCollectionNavigationVisitor(queryContext.EdmModel).Visit(expression);
expression = new NullPropagationVisitor().Visit(expression);
expression = queryContext.TranslateSource(dataContext, expression);
var query = (Func <TResult>)Expression.Lambda(expression).Compile();
cacheContext = queryContext.CreateCacheContext(variableVisitor.ConstantToParameterMapper);
executor = new InMemoryScalarExecutor <TResult>(query, variableVisitor.ParameterValues, variableVisitor.Parameters);
base.QueryCache.AddQuery(cacheContext, (query, variableVisitor.Parameters), null, queryContext.EntryFactory);
parameterValues = variableVisitor.ParameterValues;
}
else
{
executor = (InMemoryScalarExecutor <TResult>)queryCacheItem.Query;
queryContext.EntryFactory = queryCacheItem.EntryFactory;
parameterValues = cacheContext.ParameterValues;
}
lock (executor)
{
for (int i = 0; i < parameterValues.Count; i++)
{
executor[parameterValues[i].ParameterName] = parameterValues[i].ParameterValue;
}
return(executor.Execute());
}
}
