//p=>p
//p=>p.t
//p=>p.Id
protected override Expression VisitLambda <T>(Expression <T> node)
{
LambdaExpression lambda = node as LambdaExpression;
if (lambda.Body.NodeType == ExpressionType.Parameter)
{
// 例： a=> a
Type type = lambda.Body.Type;
string alias = _aliases.GetTableAlias(lambda);
this.VisitAllMember(type, alias);
return(node);
}
else if (lambda.Body.CanEvaluate())
{
// 例：a=>1
base.Visit(lambda.Body.Evaluate());
// 选择字段
string newName = AddColumn(_columns, "__Constant__");
// 添加字段别名
_builder.AppendAs(newName);
return(node);
}
else if (lambda.Body.NodeType == ExpressionType.MemberAccess)
{
// 例： t=> t.a
// => SELECT a.ClientId
Type type = lambda.Body.Type;
return(TypeUtils.IsPrimitiveType(type)
? base.VisitLambda(node)
: this.VisitAllMember(type, _aliases.GetTableAlias(lambda.Body), node));
}
return(base.VisitLambda(node));
}
// 判定 MemberInit 绑定是否声明了一对多关系的导航
static bool CheckListNavigation <T>(MemberInitExpression node)
{
for (int i = 0; i < node.Bindings.Count; i++)
{
// primitive 类型
Type type = (node.Bindings[i].Member as System.Reflection.PropertyInfo).PropertyType;
if (TypeUtils.IsPrimitiveType(type))
{
continue;
}
// complex 类型
if (TypeUtils.IsCollectionType(type))
{
return(true);
}
MemberAssignment memberAssignment = node.Bindings[i] as MemberAssignment;
if (memberAssignment != null && memberAssignment.Expression.NodeType == ExpressionType.MemberInit)
{
MemberInitExpression initExpression = memberAssignment.Expression as MemberInitExpression;
bool checkListNavgation = CheckListNavigation <T>(initExpression);
if (checkListNavgation)
{
return(true);
}
}
}
return(false);
}
// 遍历New表达式的参数集
private Expression VisitNewImpl(NewExpression node)
{
for (int i = 0; i < node.Arguments.Count; i++)
{
Expression argument = node.Arguments[i];
Type type = argument.Type;
if (argument.NodeType == ExpressionType.Parameter)
{
//例： new Client(a)
string alias = _aliases.GetTableAlias(argument);
this.VisitAllMember(type, alias);
}
else if (argument.CanEvaluate())
{
//例： DateTime.Now
_builder.Append(argument.Evaluate().Value, node.Members[i], node.Type);
string newName = AddColumn(_columns, node.Members != null ? node.Members[i].Name : (argument as MemberExpression).Member.Name);
_builder.AppendAs(newName);
_builder.Append(',');
_builder.AppendNewLine();
}
else if (argument.NodeType == ExpressionType.MemberAccess || argument.NodeType == ExpressionType.Call)
{
if (TypeUtils.IsPrimitiveType(type))
{
// new Client(a.ClientId)
this.Visit(argument);
string newName = AddColumn(_columns, node.Members != null ? node.Members[i].Name : (argument as MemberExpression).Member.Name);
_builder.AppendAs(newName);
_builder.Append(',');
_builder.AppendNewLine();
}
else
{
this.VisitNavigation(argument as MemberExpression, false);
}
}
else
{
throw new XFrameworkException("VisitNewImpl: NodeType '{0}' not supported.", argument.NodeType);
}
base._visitedMember.Clear();
}
return(node);
}
///// <summary>
///// 获取XML类型的 SQL 片断
///// </summary>
//protected virtual string GetSqlValueByXml(object value, object dbType, int? size = null, int? precision = null, int? scale = null, ParameterDirection? direction = null)
//{
// return this.EscapeQuote(((SqlXml)value).Value, false, true);
//}
/// <summary>
/// 获取其它类型的 SQL 片断
/// </summary>
protected virtual string GetSqlValueByOther(object value, object dbType, int?size = null, int?precision = null, int?scale = null, ParameterDirection?direction = null)
{
if (value is byte[])
{
throw new NotSupportedException("System.Byte[] does not support serialization into strings.");
}
if (TypeUtils.IsPrimitiveType(value.GetType()))
{
return(value.ToString());
}
else
{
return(this.EscapeQuote(value.ToString(), false, false));
}
}
protected override Expression VisitMember(MemberExpression node)
{
// 1.<>h__TransparentIdentifier3.b.Client.ClientName
// 2.<>h__TransparentIdentifier3.b.Client.ClientName.Length
// 3.<>h__TransparentIdentifier3.b.Client.Address.AddressName
// 4.<>h__TransparentIdentifier3.b.ClientName
// <>h__TransparentIdentifier2.<>h__TransparentIdentifier3.b.ClientName
// <>h__TransparentIdentifier2.<>h__TransparentIdentifier3.b.Client.ClientName
// <>h__TransparentIdentifier2.<>h__TransparentIdentifier3.b.Client.Address.AddressName
// 5.b.ClientName
_visitedMember.Add(node);
if (node == null)
{
return(node);
}
// => a.ActiveDate == DateTime.Now => a.State == (byte)state
if (node.CanEvaluate())
{
return(this.VisitConstant(node.Evaluate()));
}
// => a.Name.Length
if (TypeUtils.IsPrimitiveType(node.Expression.Type))
{
return(_methodVisitor.VisitMemberMember(node));
}
// => <>h__3.b.ClientName
if (!node.Expression.Acceptable())
{
return(_builder.AppendMember(node, _aliases));
}
// => b.Client.Address.AddressName
this.VisitNavMember(node.Expression, node.Member.Name);
return(node);
}
// {new App() {Id = p.Id}}
private Expression VisitMemberInitImpl(MemberInitExpression node, bool topBinding)
{
// 如果有一对多的导航属性会产生嵌套的SQL，这时需要强制主表选择的列里面必须包含导航外键
// TODO #对 Bindings 进行排序，保证导航属性的赋值一定要最后面#
// 未实现，在书写表达式时人工保证 ##
if (node.NewExpression != null)
{
this.VisitNewImpl(node.NewExpression);
}
if (_navChainHopper.Count == 0)
{
_navChainHopper.Add(node.Type.Name);
}
for (int i = 0; i < node.Bindings.Count; i++)
{
MemberAssignment binding = node.Bindings[i] as MemberAssignment;
if (binding == null)
{
throw new XFrameworkException("Only 'MemberAssignment' binding supported.");
}
Type propertyType = (node.Bindings[i].Member as System.Reflection.PropertyInfo).PropertyType;
bool isNavigation = !TypeUtils.IsPrimitiveType(propertyType);
#region 一般属性
// 非导航属性
if (!isNavigation)
{
if (binding.Expression.CanEvaluate())
{
_builder.Append(binding.Expression.Evaluate().Value, binding.Member, node.Type);
}
else
{
base.VisitMemberBinding(binding);
}
// 选择字段
string newName = AddColumn(_columns, binding.Member.Name);
// 添加字段别名
_builder.AppendAs(newName);
_builder.Append(',');
_builder.AppendNewLine();
}
#endregion
#region 导航属性
else
{
// 非显式指定的导航属性需要有 ForeignKeyAttribute
if (binding.Expression.NodeType == ExpressionType.MemberAccess && binding.Expression.Acceptable())
{
TypeRuntimeInfo typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(binding.Member.DeclaringType);
var attribute = typeRuntime.GetInvokerAttribute <ForeignKeyAttribute>(binding.Member.Name);
if (attribute == null)
{
throw new XFrameworkException("Complex property {{{0}}} must mark 'ForeignKeyAttribute' ", binding.Member.Name);
}
}
// 生成导航属性描述集合，以类名.属性名做为键值
int n = _navChainHopper.Count;
string keyName = _navChainHopper.Count > 0 ? _navChainHopper[_navChainHopper.Count - 1] : string.Empty;
keyName = !string.IsNullOrEmpty(keyName) ? keyName + "." + binding.Member.Name : binding.Member.Name;
Navigation descriptor = new Navigation(keyName, binding.Member);
if (!_navigations.ContainsKey(keyName))
{
// fix issue# XC 列占一个位
descriptor.Start = _columns.Count;
descriptor.FieldCount = GetFieldCount(binding.Expression) + (binding.Expression.NodeType == ExpressionType.MemberAccess && binding.Expression.Acceptable() ? 1 : 0);
_navigations.Add(keyName, descriptor);
_navChainHopper.Add(keyName);
}
// 1.不显式指定导航属性，例：a.Client.ClientList
// 2.表达式里显式指定导航属性，例：b
if (binding.Expression.NodeType == ExpressionType.MemberAccess)
{
this.VisitNavigation(binding.Expression as MemberExpression, binding.Expression.Acceptable());
}
else if (binding.Expression.NodeType == ExpressionType.New)
{
this.VisitNewImpl(binding.Expression as NewExpression);
}
else if (binding.Expression.NodeType == ExpressionType.MemberInit)
{
this.VisitMemberInitImpl(binding.Expression as MemberInitExpression, false);
}
// 恢复访问链
// 在访问导航属性时可能是 Client.CloudServer，这时要恢复为 Client，以保证能访问 Client 的下一个导航属性
if (_navChainHopper.Count != n)
{
_navChainHopper.RemoveAt(_navChainHopper.Count - 1);
}
}
#endregion
base._visitedMember.Clear();
}
return(node);
}
/// <summary>
/// 将 <see cref="IDataRecord"/> 上的当前行反序列化为实体
/// </summary>
/// <param name="prevModel">前一行数据</param>
/// <param name="isThisLine">是否同一行数据</param>
internal T Deserialize(object prevModel, out bool isThisLine)
{
isThisLine = false;
#region 基元类型
string name = _reader.GetName(0);
if (TypeUtils.IsPrimitiveType(typeof(T)) || name == Constant.AUTOINCREMENTNAME)
{
if (_reader.IsDBNull(0))
{
return(default(T));
}
var obj = _reader.GetValue(0);
if (obj.GetType() != typeof(T))
{
// fix#Nullable<T> issue
if (!typeof(T).IsGenericType)
{
obj = Convert.ChangeType(obj, typeof(T));
}
else
{
Type g = typeof(T).GetGenericTypeDefinition();
if (g != typeof(Nullable <>))
{
throw new NotSupportedException(string.Format("type {0} not suppored.", g.FullName));
}
obj = Convert.ChangeType(obj, Nullable.GetUnderlyingType(typeof(T)));
}
}
return((T)obj);
}
#endregion
#region 动态类型
if (typeof(T) == typeof(ExpandoObject) || typeof(T) == typeof(object))
{
ExpandoObject obj = new ExpandoObject();
var result = ((IDictionary <string, object>)obj);
for (int i = 0; i < _reader.FieldCount; i++)
{
var value = _reader.GetValue(i);
if (value == DBNull.Value)
{
value = null;
}
result.Add(_reader.GetName(i), value);
}
return((dynamic)obj);
}
#endregion
#region 实体类型
T model = default(T);
TypeRuntimeInfo typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
if (_definition == null || _definition.Navigations == null || _definition.Navigations.Count == 0)
{
// 没有字段映射说明或者没有导航属性
if (_modelDeserializer == null)
{
_modelDeserializer = InternalTypeDeserializer.GetTypeDeserializer(typeof(T), _reader, _definition != null ? _definition.Columns : null, 0);
}
model = (T)_modelDeserializer(_reader);
}
else
{
// 第一层
if (_modelDeserializer == null)
{
_modelDeserializer = InternalTypeDeserializer.GetTypeDeserializer(typeof(T), _reader, _definition.Columns, 0, _definition.Navigations.MinIndex);
}
model = (T)_modelDeserializer(_reader);
// 若有 1:n 的导航属性，判断当前行数据与上一行数据是否相同
if (prevModel != null && _definition.HaveListNavigation)
{
isThisLine = true;
foreach (var key in typeRuntime.KeyInvokers)
{
var invoker = key.Value;
var value1 = invoker.Invoke(prevModel);
var value2 = invoker.Invoke(model);
isThisLine = isThisLine && value1.Equals(value2);
if (!isThisLine)
{
// fix issue#换行时清空上一行的导航键缓存
_listNavigationKeys.Clear();
break;
}
}
}
// 递归导航属性
this.Deserialize_Navigation(isThisLine ? prevModel : null, model, string.Empty, isThisLine);
}
return(model);
#endregion
}
// 构造由一对多关系产生的嵌套查询
static DbQueryableInfo_Select <TElement> TryBuilOuter <TElement>(DbQueryableInfo_Select <TElement> sQuery)
{
if (sQuery == null || sQuery.Select == null)
{
return(sQuery);
}
Expression select = sQuery.Select.Expressions[0];
List <DbExpression> include = sQuery.Include;
Type type = sQuery.FromType;
// 解析导航属性 如果有 一对多 的导航属性，那么查询的结果集的主记录将会有重复记录，这时就需要使用嵌套语义，先查主记录，再关联导航记录
bool checkListNavgation = false;
Expression expression = select;
LambdaExpression lambdaExpression = expression as LambdaExpression;
if (lambdaExpression != null)
{
expression = lambdaExpression.Body;
}
MemberInitExpression initExpression = expression as MemberInitExpression;
NewExpression newExpression = expression as NewExpression;
foreach (DbExpression d in include)
{
Expression exp = d.Expressions[0];
if (exp.NodeType == ExpressionType.Lambda)
{
exp = (exp as LambdaExpression).Body;
}
else if (exp.NodeType == ExpressionType.Call)
{
exp = (exp as MethodCallExpression).Object;
}
// Include 如果包含List<>泛型导航，则可以判定整个查询包含一对多的导航
//if (exp.Type.IsGenericType && exp.Type.GetGenericTypeDefinition() == typeof(List<>)) checkListNavgation = true;
if (TypeUtils.IsCollectionType(exp.Type))
{
checkListNavgation = true;
}
if (checkListNavgation)
{
break;
}
}
if (!checkListNavgation)
{
checkListNavgation = initExpression != null && CheckListNavigation <TElement>(initExpression);
}
if (checkListNavgation)
{
newExpression = initExpression != null ? initExpression.NewExpression : newExpression;
List <MemberBinding> bindings = new List <MemberBinding>();
if (initExpression != null)
{
bindings = initExpression.Bindings.ToList(x => x, x => TypeUtils.IsPrimitiveType((x.Member as System.Reflection.PropertyInfo).PropertyType));
}
if (newExpression != null || bindings.Count() > 0)
{
// 简化内层选择器，只选择最小字段，不选择导航字段，导航字段在外层加进去
initExpression = Expression.MemberInit(newExpression, bindings);
lambdaExpression = Expression.Lambda(initExpression, lambdaExpression.Parameters);
sQuery.Select = new DbExpression(DbExpressionType.Select, lambdaExpression);
}
sQuery.GenByListNavigation = true;
sQuery.Include = new List <DbExpression>();
var outQuery = new DbQueryableInfo_Select <TElement>();
outQuery.FromType = type;
outQuery.SubQueryInfo = sQuery;
outQuery.Join = new List <DbExpression>();
outQuery.OrderBy = new List <DbExpression>();
outQuery.Include = include;
outQuery.HaveListNavigation = true;
outQuery.Select = new DbExpression(DbExpressionType.Select, select);
if (sQuery.GroupBy != null)
{
// 查看外层是否需要重新构造选择器。如果有分组并且有聚合函数，则需要重新构造选择器。否则外层解析不了聚合函数
// demo=> line 640
bool newSelector = bindings.Any(x => ((MemberAssignment)x).Expression.NodeType == ExpressionType.Call) ||
newExpression.Arguments.Any(x => x.NodeType == ExpressionType.Call);
if (newSelector)
{
// 1对多导航嵌套查询外层的的第一个表别名固定t0，参数名可随意
ParameterExpression p = Expression.Parameter(newExpression.Type, "__g");
bindings = bindings.ToList(x => (MemberBinding)Expression.Bind(x.Member, Expression.MakeMemberAccess(p, x.Member)));
List <Expression> arguments = null;
if (newExpression.Members != null)
{
arguments = new List <Expression>(newExpression.Arguments.Count);
for (int i = 0; i < newExpression.Arguments.Count; i++)
{
var member = newExpression.Members[i];
var arg = Expression.MakeMemberAccess(p, member);
arguments.Add(arg);
}
}
newExpression = Expression.New(newExpression.Constructor, arguments, newExpression.Members);
initExpression = Expression.MemberInit(newExpression, bindings);
lambdaExpression = Expression.Lambda(initExpression, lambdaExpression.Parameters);
outQuery.Select = new DbExpression(DbExpressionType.Select, lambdaExpression);
}
}
sQuery = outQuery;
}
else if (sQuery.Union.Count > 0 && (sQuery.Take > 0 || sQuery.Skip > 0))
{
var outQuery = new DbQueryableInfo_Select <TElement>();
outQuery.FromType = type;
outQuery.Select = new DbExpression(DbExpressionType.Select, select);
outQuery.SubQueryInfo = sQuery;
outQuery.Skip = sQuery.Skip;
outQuery.Take = sQuery.Take;
outQuery.Join = new List <DbExpression>();
outQuery.OrderBy = new List <DbExpression>();
outQuery.OrderBy.AddRange(sQuery.OrderBy);
sQuery.OrderBy = new List <DbExpression>();
sQuery.Skip = 0;
sQuery.Take = 0;
sQuery = outQuery;
}
return(sQuery);
}