private static bool CheckShortCircuitSum(SubQueryExpression expression, MainQueryParts queryParts, Action<Expression> visitExpression)
{
var subquery = SubqueryGeneratorQueryModelVisitor.ParseSubquery(expression.QueryModel, queryParts, true);
if (subquery.ShouldQueryInMemory)
{
throw new NotImplementedException("Unsupported subquery. Please provide more info about query.");
//return false;
}
var sql = subquery.BuildSqlString(false);
var cnt = queryParts.CurrentSelectIndex;
var selector = expression.QueryModel.SelectClause.Selector as MemberExpression;
if (selector == null)
return false;
var type = expression.QueryModel.ResultTypeOverride;
if (type.IsNullable())
type = type.GetGenericArguments()[0];
queryParts.AddSelectPart(
expression.QueryModel.MainFromClause,
@"(SELECT SUM((""{1}"").""{3}"") FROM ({2}) ""{1}"") AS ""{0}""".With(
"_subquery_" + cnt,
expression.QueryModel.MainFromClause.ItemName,
sql,
selector.Member.Name),
"_sum_" + cnt,
expression.QueryModel.ResultTypeOverride,
(_, dr) => dr.IsDBNull(cnt) ? 0 : Convert.ChangeType(dr.GetValue(cnt), type));
return true;
}
public bool TryMatch(Expression expression, MainQueryParts queryParts, Action<Expression> visitExpression)
{
var sq = expression as SubQueryExpression;
return sq != null
&& sq.QueryModel.ResultOperators.Count == 1
&& sq.QueryModel.ResultOperators[0] is SumResultOperator
&& CheckShortCircuitSum(sq, queryParts, visitExpression);
}
public SqlCommandData(MainQueryParts query)
{
this.Query = query;
Statement = query.BuildSqlString();
var mainIndex = query.Selects.FindIndex(it => it.QuerySource == query.MainFrom);
if (mainIndex > 0)
{
var main = query.Selects[mainIndex];
query.Selects.RemoveAt(mainIndex);
query.Selects.Insert(0, main);
}
}
private static bool CheckShortCircuitCount(SubQueryExpression expression, MainQueryParts queryParts, Action<Expression> visitExpression)
{
var subquery = SubqueryGeneratorQueryModelVisitor.ParseSubquery(expression.QueryModel, queryParts, true);
if (subquery.ShouldQueryInMemory)
{
throw new NotImplementedException("Unsupported subquery. Please provide more info about query.");
//return false;
}
var cnt = queryParts.CurrentSelectIndex;
var mq = subquery.MainFrom.FromExpression as QuerySourceReferenceExpression;
if (mq != null && subquery.Joins.Count == 0 && subquery.AdditionalJoins.Count == 0 && subquery.Conditions.Count == 0)
{
if (mq.ReferencedQuerySource.ItemType.IsGrouping())
{
queryParts.AddSelectPart(
expression.QueryModel.MainFromClause,
"ARRAY_UPPER(\"{0}\".\"Values\", 1) AS \"_count_helper_{1}\"".With(mq.ReferencedQuerySource.ItemName, cnt),
"_count_helper_" + cnt,
expression.QueryModel.ResultTypeOverride,
(_, dr) => dr.IsDBNull(cnt) ? 0 : Convert.ChangeType(dr.GetValue(cnt), expression.QueryModel.ResultTypeOverride));
return true;
}
}
var sql = subquery.BuildSqlString(false);
queryParts.AddSelectPart(
expression.QueryModel.MainFromClause,
@"(SELECT COUNT(""{1}"") FROM ({2}) ""{1}"") AS ""{0}"" ".With(
"_subquery_" + cnt,
expression.QueryModel.MainFromClause.ItemName,
sql),
"_count_" + cnt,
expression.QueryModel.ResultTypeOverride,
(_, dr) => dr.IsDBNull(cnt) ? 0 : Convert.ChangeType(dr.GetValue(cnt), expression.QueryModel.ResultTypeOverride));
return true;
}
public SqlGeneratorQueryModelVisitor(MainQueryParts queryParts)
{
Contract.Requires(queryParts != null);
this.QueryParts = queryParts;
}
