/// <summary>
/// Join,并返回筛选值
/// </summary>
/// <typeparam name="TInner">关联类型</typeparam>
/// <param name="expression">关关表达式</param>
/// <param name="resultSelector">返回值</param>
/// <param name="joinType">join类型,默认Left</param>
/// <returns></returns>
public LambdaQuery <T> Join <TInner>(
Expression <Func <T, TInner, bool> > expression,
Expression <Func <T, TInner, object> > resultSelector, JoinType joinType = JoinType.Left) where TInner : IModel, new()
{
var innerType = typeof(TInner);
//TypeCache.SetDBAdapterCache(innerType, dBAdapter);
string condition = FormatJoinExpression(expression);
var allFilds1 = TypeCache.GetProperties(typeof(T), true);
var allFilds2 = TypeCache.GetProperties(innerType, true);
var dic = new Dictionary <string, Type>();
foreach (var item in resultSelector.Parameters)
{
dic.Add(item.Name, item.Type);
}
QueryFields.Clear();
List <Attribute.FieldAttribute> resultFields = new List <Attribute.FieldAttribute>();
var newExpression = resultSelector.Body as NewExpression;
int i = 0;
foreach (var item in newExpression.Arguments)
{
var arry = item.ToString().Split('.');
var aliasName = arry[0]; //like a
var type1 = dic[aliasName];
aliasName = GetPrefix(type1); //前缀
Attribute.FieldAttribute f;
string name = newExpression.Members[i].Name;
if (type1 == innerType)//关联
{
//f = allFilds2.Find(b => b.Name == arry[1]);
f = allFilds2[arry[1]];
f.AliasesName = name;
if (resultFields.Find(b => b.ToString() == f.ToString()) != null)
{
throw new Exception("不能指定多次相同的字段" + f.Name);
}
resultFields.Add(f);
}
else//自已
{
//f = allFilds1.Find(b => b.Name == arry[1]);
f = allFilds1[arry[1]];
if (QueryFields.Find(b => b.ToString() == f.ToString()) != null)
{
throw new Exception("不能指定多次相同的字段" + f.Name);
}
f.AliasesName = name;
f.SetFieldQueryScript(GetPrefix(), true, true);
QueryFields.Add(f);
}
i += 1;
}
AddInnerRelation(innerType, condition, resultFields, true, joinType);
return(this);
}
public void AddFieldMapping(string field, int location)
{
if (QueryFields == null)
{
QueryFields = new Dictionary <string, int>();
}
field = field.Split('.').Last().Replace("\"", "").ToUpper();
if (!QueryFields.ContainsKey(field))
{
QueryFields.Add(field, location);
}
}
