protected override Expression VisitMember(MemberExpression m)
{
var source = Visit(m.Expression);
IProperty property;
// **fix** 解决无法返回两级以上关联对象的问题
// var ex = source as EntityExpression
// if (ex != null &&
if ((property = PropertyUnity.GetProperty(m.Expression.Type, m.Member.Name)) != null &&
property is RelationProperty)
{
var projection = (ProjectionExpression)Visit(QueryUtility.GetMemberExpression(source, property));
if (currentFrom != null && m.Member.GetMemberType().GetEnumerableType() == null)
{
// convert singleton associations directly to OUTER APPLY
projection = projection.AddOuterJoinTest();
var newFrom = new JoinExpression(JoinType.OuterApply, currentFrom, projection.Select, null);
currentFrom = newFrom;
return(projection.Projector);
}
return(projection);
}
var result = QueryBinder.BindMember(source, m.Member);
if (result is MemberExpression mex &&
mex.Member == m.Member &&
mex.Expression == m.Expression)
{
return(m);
}
return(result);
}
protected override Expression VisitBinary(BinaryExpression b)
{
var left = Visit(b.Left);
var right = Visit(b.Right);
if (left is NamedValueExpression nv0 && right is ColumnExpression c0)
{
left = QueryUtility.GetNamedValueExpression(nv0.Name, nv0.Value, (DbType)c0.MapInfo.DataType);
}
protected override ColumnAssignment VisitColumnAssignment(ColumnAssignment ca)
{
ca = base.VisitColumnAssignment(ca);
Expression expression = ca.Expression;
if (expression is NamedValueExpression nv)
{
expression = QueryUtility.GetNamedValueExpression(nv.Name, nv.Value, (DbType)ca.Column.MapInfo.DataType);
}
return(this.UpdateColumnAssignment(ca, ca.Column, expression));
}
protected override Expression VisitEntity(EntityExpression entity)
{
var init = entity.Expression as MemberInitExpression;
if (init != null)
{
var save = includeScope;
includeScope = new ScopedDictionary <IProperty, bool>(this.includeScope);
List <MemberBinding> newBindings = null;
foreach (var property in PropertyUnity.GetRelatedProperties(entity.Type))
{
PropertyInfo member;
if (property is IPropertyLazy && policy.IsIncluded(member = property.Info.ReflectionInfo))
{
if (includeScope.ContainsKey(property))
{
throw new NotSupportedException(string.Format("Cannot include '{0}.{1}' recursively.", property.Type, property.Name));
}
var me = QueryUtility.GetMemberExpression(init, property);
if (newBindings == null)
{
newBindings = new List <MemberBinding>(init.Bindings);
}
newBindings.Add(Expression.Bind(member, me));
}
}
if (newBindings != null)
{
entity = new EntityExpression(entity.Metadata, Expression.MemberInit(init.NewExpression, newBindings));
}
includeScope = save;
}
return(base.VisitEntity(entity));
}
protected override Expression VisitBinary(BinaryExpression b)
{
Expression left = this.Visit(b.Left);
Expression right = this.Visit(b.Right);
if (left.NodeType == (ExpressionType)DbExpressionType.NamedValue &&
right.NodeType == (ExpressionType)DbExpressionType.Column)
{
NamedValueExpression nv = (NamedValueExpression)left;
ColumnExpression c = (ColumnExpression)right;
left = QueryUtility.GetNamedValueExpression(nv.Name, nv.Value, (DbType)c.MapInfo.DataType);
}
else if (b.Right.NodeType == (ExpressionType)DbExpressionType.NamedValue &&
b.Left.NodeType == (ExpressionType)DbExpressionType.Column)
{
NamedValueExpression nv = (NamedValueExpression)right;
ColumnExpression c = (ColumnExpression)left;
right = QueryUtility.GetNamedValueExpression(nv.Name, nv.Value, (DbType)c.MapInfo.DataType);
}
return(b.Update(left, b.Conversion, right));
}