protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall,
BuildInfo buildInfo)
{
var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0]));
var collectionSelector = (LambdaExpression)methodCall.Arguments[1].Unwrap();
var resultSelector = (LambdaExpression)methodCall.Arguments[2].Unwrap();
if (!sequence.Select.GroupBy.IsEmpty)
{
sequence = new SubQueryContext(sequence);
}
var context = new SelectManyContext(buildInfo.Parent, collectionSelector, sequence);
var expr = collectionSelector.Body.Unwrap();
var collectionInfo = new BuildInfo(context, expr, new SelectQuery());
var collection = builder.BuildSequence(collectionInfo);
var leftJoin = collection is DefaultIfEmptyBuilder.DefaultIfEmptyContext;
var sql = collection.Select;
var sequenceTables = new HashSet <ISqlTableSource>(sequence.Select.From.Tables.First.Value.GetTables());
var newQuery = sql != collectionInfo.SelectQuery &&
QueryVisitor.FindFirstOrDefault <ISelectQuery>(sql, e => e == collectionInfo.SelectQuery) ==
null;
var crossApply = null !=
QueryVisitor.FindFirstOrDefault <IQueryExpression>(
sql,
e =>
e.ElementType == EQueryElementType.TableSource &&
sequenceTables.Contains((ISqlTableSource)e) ||
e.ElementType == EQueryElementType.SqlField &&
sequenceTables.Contains(((ISqlField)e).Table) ||
e.ElementType == EQueryElementType.Column &&
sequenceTables.Contains(((IColumn)e).Parent));
var groupJoinSubQueryContext = collection as JoinBuilder.GroupJoinSubQueryContext;
if (groupJoinSubQueryContext != null)
{
var groupJoin = groupJoinSubQueryContext.GroupJoin;
var joinedTables = groupJoin.Select.From.Tables.First.Value.Joins.First.Value;
joinedTables.JoinType = EJoinType.Inner;
joinedTables.IsWeak = false;
}
if (newQuery)
{
context.Collection = new SubQueryContext(collection, sequence.Select, false);
return(new SelectContext(buildInfo.Parent, resultSelector, sequence, context));
}
if (!crossApply)
{
if (!leftJoin)
{
context.Collection = new SubQueryContext(collection, sequence.Select, true);
return(new SelectContext(buildInfo.Parent, resultSelector, sequence, context));
}
var join = SelectQuery.OuterApply(sql);
sequence.Select.From.Tables.First.Value.Joins.AddLast(join.JoinedTable);
context.Collection = new SubQueryContext(collection, sequence.Select, false);
return(new SelectContext(buildInfo.Parent, resultSelector, sequence, context));
}
var tableContext = collection as TableBuilder.TableContext;
if (tableContext != null)
{
var join = tableContext.SqlTable.TableArguments != null &&
tableContext.SqlTable.TableArguments.Count > 0
? (leftJoin
? SelectQuery.OuterApply(sql)
: SelectQuery.CrossApply(sql))
: (leftJoin
? SelectQuery.LeftJoin(sql)
: SelectQuery.InnerJoin(sql));
join.JoinedTable.Condition.Conditions.AddRange(sql.Where.Search.Conditions);
join.JoinedTable.CanConvertApply = false;
sql.Where.Search.Conditions.Clear();
var collectionParent = collection.Parent as TableBuilder.TableContext;
// Association.
//
if (collectionParent != null && collectionInfo.IsAssociationBuilt)
{
QueryVisitor.FindFirstOrDefault <ITableSource>(sequence.Select.From,
t => t.Source == collectionParent.SqlTable);
}
else
{
sequence.Select.From.Tables.First.Value.Joins.AddLast(join.JoinedTable);
}
context.Collection = new SubQueryContext(collection, sequence.Select, false);
return(new SelectContext(buildInfo.Parent, resultSelector, sequence, context));
}
else
{
var join = leftJoin
? SelectQuery.OuterApply(sql)
: SelectQuery.CrossApply(sql);
sequence.Select.From.Tables.First.Value.Joins.AddLast(join.JoinedTable);
context.Collection = new SubQueryContext(collection, sequence.Select, false);
return(new SelectContext(buildInfo.Parent, resultSelector, sequence, context));
}
}