// Client = a.Client.CloudServer
private Expression VisitNavigation(MemberExpression node, bool visitNavigation)
{
string alias = string.Empty;
Type type = node.Type;
if (node.Acceptable())
{
// 例： Client = a.Client.CloudServer
// fix issue# Join 表达式显式指定导航属性时时，alias 为空
// fix issue# 多个导航属性时 AppendNullColumn 只解析当前表达式的
int index = 0;
int num = this.NavMembers != null ? this.NavMembers.Count : 0;
alias = this.VisitNavMember(node);
if (num != this.NavMembers.Count)
{
foreach (var kvp in NavMembers)
{
index += 1;
if (index < NavMembers.Count && index > num)
{
alias = _aliases.GetNavigationTableAlias(kvp.Key);
//navKey = kvp.Key;
//if (visitNavigation) AppendNullColumn(kvp.Value.Member, alias, navKey);
continue;
}
//navKey = kvp.Key;
alias = _aliases.GetNavigationTableAlias(kvp.Key);
type = kvp.Value.Type;
}
}
else
{
}
}
else
{
// 例： Client = b
alias = _aliases.GetTableAlias(node);
type = node.Type;
}
if (type.IsGenericType)
{
type = type.GetGenericArguments()[0];
}
this.VisitAllMember(type, alias);
if (visitNavigation)
{
AppendNullColumn(node.Member, alias);
}
return(node);
}
private static string GetTableAliasKey(Expression exp)
{
if (exp == null)
{
return(null);
}
Expression expression = exp.ReduceUnary();
//c
if (exp.CanEvaluate())
{
return(null);
}
// p
ParameterExpression paramExp = expression as ParameterExpression;
if (paramExp != null)
{
return(paramExp.Name);
}
// a=>a.Id
LambdaExpression lambdaExp = expression as LambdaExpression;
if (lambdaExp != null)
{
expression = lambdaExp.Body.ReduceUnary();
}
// a.Id
// t.a
// t.t.a
// t.a.Id
MemberExpression memExp = expression as MemberExpression;
if (memExp == null)
{
return(TableAliasCache.GetTableAliasKey(expression));
}
if (memExp.Acceptable())
{
return(TableAliasCache.GetTableAliasKey(memExp.Expression));
}
return(memExp.Member.Name);
}
// => Client = a.Client.CloudServer
private Expression VisitNavigation(MemberExpression node, bool visitNavigation, Expression pickExpression = null)
{
string alias = string.Empty;
Type type = node.Type;
if (node.Acceptable())
{
// 例： Client = a.Client.CloudServer
// fix issue# Join 表达式显式指定导航属性时时，alias 为空
// fix issue# 多个导航属性时 AppendNullColumn 只解析当前表达式的
int index = 0;
int num = this.NavMembers != null ? this.NavMembers.Count : 0;
alias = this.VisitNavMember(node);
if (num != this.NavMembers.Count)
{
foreach (var kvp in NavMembers)
{
index += 1;
if (index < NavMembers.Count && index > num)
{
alias = _aliases.GetNavigationTableAlias(kvp.Key);
}
else
{
alias = _aliases.GetNavigationTableAlias(kvp.Key);
type = kvp.Value.Type;
}
}
}
else
{
}
}
else
{
// 例： Client = b
alias = _aliases.GetTableAlias(node);
type = node.Type;
}
if (type.IsGenericType)
{
type = type.GetGenericArguments()[0];
}
if (pickExpression == null)
{
this.VisitAllMember(type, alias);
}
else
{
// Include 中选中的字段
Expression expr = pickExpression;
if (expr.NodeType == ExpressionType.Lambda)
{
expr = (pickExpression as LambdaExpression).Body;
}
if (expr.NodeType == ExpressionType.New)
{
var newExpression = expr as NewExpression;
for (int i = 0; i < newExpression.Arguments.Count; i++)
{
var memberExpression = newExpression.Arguments[i] as MemberExpression;
if (memberExpression == null)
{
throw new XFrameworkException("MemberExpression required at the {0} arguments.", i);
}
_builder.AppendMember(alias, memberExpression.Member.Name);
this.AddPickColumn(newExpression.Members != null ? newExpression.Members[i].Name : memberExpression.Member.Name);
}
}
else if (expr.NodeType == ExpressionType.MemberInit)
{
var initExpression = expr as MemberInitExpression;
for (int i = 0; i < initExpression.Bindings.Count; i++)
{
var binding = initExpression.Bindings[i] as MemberAssignment;
if (binding == null)
{
throw new XFrameworkException("Only 'MemberAssignment' binding supported.");
}
var memberExpression = binding.Expression as MemberExpression;
if (memberExpression == null)
{
throw new XFrameworkException("MemberExpression required at the {0} arguments.", i);
}
_builder.AppendMember(alias, memberExpression.Member.Name);
this.AddPickColumn(binding.Member.Name);
}
}
else
{
throw new NotSupportedException(string.Format("Include method not supporte {0}", expr.NodeType));
}
}
if (visitNavigation)
{
AddSplitOnColumn(node.Member, alias);
}
return(node);
}
