public static SubqueryParts ParseSubquery(QueryModel queryModel, QueryParts parentQuery, bool canQueryInMemory, string contextName, QueryContext context)
{
var visitor = new SubqueryGeneratorQueryModelVisitor(parentQuery, canQueryInMemory, queryModel.SelectClause.Selector, contextName, context);
visitor.VisitQueryModel(queryModel);
return(visitor.QueryParts);
}
protected override Expression VisitSubQueryExpression(SubQueryExpression expression)
{
//TODO select, where?
var subquery = SubqueryGeneratorQueryModelVisitor.ParseSubquery(expression.QueryModel, QueryParts, false, ContextName, Context);
SqlExpression.AppendFormat("({0})", subquery.BuildSqlString(true));
return(expression);
}
protected override Expression VisitSubQueryExpression(SubQueryExpression expression)
{
var sqParts = new SubqueryParts(Query, expression.QueryModel.SelectClause.Selector, Query.ContextName, Query.Context.Select());
var sq = SubqueryGeneratorQueryModelVisitor.ParseSubquery(expression.QueryModel, sqParts, Query.ContextName, Query.Context.Select());
if (!Query.CanQueryInMemory)
{
Query.AddSelectPart(
null,
"(" + sq.BuildSqlString(true) + ")",
null,
expression.QueryModel.ResultTypeOverride ?? expression.QueryModel.SelectClause.Selector.Type,
null);
}
return(expression);
}
protected override Expression VisitSubQueryExpression(SubQueryExpression expression)
{
if (ProcessedExpressions.Contains(expression))
{
return(expression);
}
if (DataSources.Count == 0)
{
DataSources.Add(Query.MainFrom.FromExpression);
DataSources.AddRange(Query.Joins.Select(it => it.InnerSequence));
DataSources.AddRange(Query.AdditionalJoins.Select(it => it.FromExpression));
}
var model = expression.QueryModel;
if (model.BodyClauses.Count == 0 &&
DataSources.Contains(model.MainFromClause.FromExpression))
{
return(expression);
}
ProcessedExpressions.Add(expression);
foreach (var candidate in Query.ProjectionMatchers)
{
if (candidate.TryMatch(expression, Query, exp => VisitExpression(exp)))
{
return(expression);
}
}
var subquery = SubqueryGeneratorQueryModelVisitor.ParseSubquery(expression.QueryModel, Query, true, Query.ContextName, Query.Context.Select());
var cnt = Query.CurrentSelectIndex;
//TODO true or false
var sql = subquery.BuildSqlString(true);
var selector = model.SelectClause.Selector;
var projector = (IExecuteFunc)Activator.CreateInstance(typeof(GenericProjection <>).MakeGenericType(selector.Type), model);
var ssd = SelectSubqueryData.Create(Query, subquery);
if (subquery.ResultOperators.Any(it => it is FirstResultOperator))
{
//TODO fix later
Query.AddSelectPart(
expression.QueryModel.MainFromClause,
@"(SELECT ""{1}"" FROM ({2}) ""{1}"" WHERE RowNum = 1) AS ""{0}""".With(
"_first_or_default_" + cnt,
expression.QueryModel.MainFromClause.ItemName,
sql),
"_first_or_default_" + cnt,
expression.QueryModel.ResultTypeOverride,
(rom, dr) =>
{
if (dr.IsDBNull(cnt))
{
return(null);
}
var tuple = new[] { dr.GetValue(cnt).ToString() };
var result = ssd.ProcessRow(rom, tuple);
return(projector.Eval(result));
});
}
else
{
//TODO fix later
Query.AddSelectPart(
expression.QueryModel.MainFromClause,
@"(SELECT ARRAY_AGG(""{1}"") FROM ({2}) ""{1}"") AS ""{0}""".With(
"_subquery_" + cnt,
expression.QueryModel.MainFromClause.ItemName,
sql),
"_subquery_" + cnt,
expression.QueryModel.ResultTypeOverride,
(rom, dr) =>
{
//TODO fix later
return(null);
/*
* string[] array;
* if (dr.IsDBNull(cnt))
* array = new string[0];
* else
* {
* var value = dr.GetValue(cnt);
* array = value is string[] ? value as string[] : OracleRecordConverter.ParseArray(dr.GetString(cnt));
* }
* var resultItems = new List<ResultObjectMapping>();
* array.Foreach(it => resultItems.Add(ssd.ProcessRow(rom, it)));
* return projector.Process(resultItems);*/
});
}
return(expression);
}
public static SubqueryParts ParseSubquery(QueryModel queryModel, QueryParts parentQuery, bool canQueryInMemory, string contextName, QueryContext context)
{
var visitor = new SubqueryGeneratorQueryModelVisitor(parentQuery, canQueryInMemory, queryModel.SelectClause.Selector, contextName, context);
visitor.VisitQueryModel(queryModel);
return visitor.QueryParts;
}