private static string ResolveParameterExpression(ParameterExpression expression)
{
var parameterType = (expression as ParameterExpression).Type;
var typeMapping_parameterType = DbTypeMapping.TypeMapping(parameterType);
if (typeMapping_parameterType.Equals(DbTypeMapping.List_UserType))
{
if (!types.Contains(parameterType))
{
types.Add(parameterType);
}
return(null);
}
else if (typeMapping_parameterType.Equals(DbTypeMapping.UserType))
{
CreateJoin(parameterType.Name + "." + new ModelUtil(parameterType).PrimaryKeyPropertyName);
if (!types.Contains(parameterType))
{
types.Add(parameterType);
}
return((expression as ParameterExpression).Type.Name);
}
else
{
return(null);
}
}
public List <TModel> SelectModels <TModel>(Expression expression)
{
LambdaTranslator.MappingDataSet = MappingDataSet;
TranslatorResult res = LambdaTranslator.ResolveExpression(expression, true);
List <RelationModel> relations = new List <RelationModel>();
List <string> tables = new List <string>();
//遍历所有涉及到的关系
foreach (var type in res.Types)
{
if (DbTypeMapping.TypeMapping(type).Equals(DbTypeMapping.UserType))
{
var rls = MappingDataSet.GetRelation(type.Name);
relations.Add(rls);
tables.Add(rls.TbName);
}
else if (DbTypeMapping.TypeMapping(type).Equals(DbTypeMapping.List_UserType))
{
//建立新的查询，
}
}
var selectSql = Select.From(tables);
foreach (var r in relations)
{
foreach (var c in r.Columns)
{
selectSql.AddColumns(r.TbName + "." + c.ColumnName + " as " + r.TbName + "_" + c.ColumnName);
}
}
selectSql.SetWhere(res.GetWhere());
string sql_str = selectSql.ToSql().ToString();
var dataSet = GetDataSet(selectSql.ToSql());
var tabless = dataSet.Tables;
return(null);
}
public static string ResolveMemberExpression(MemberExpression expression)
{
//展开成员表达式
if (!expressionCatches.Keys.Contains(expression.ToString()))
{
var memberType = expression.Type;
var typeMapping_rightType = DbTypeMapping.TypeMapping(memberType);
if (typeMapping_rightType.Equals(DbTypeMapping.List_UserType))
{
//如果成员表达式的右边是集合类型
if (!types.Contains(memberType))
{
types.Add(memberType);
}
expressionCatches.Add(expression.ToString(), null);
return(null);
}
else if (typeMapping_rightType.Equals(DbTypeMapping.UserType))
{
//如果成员表达式的右边是用户类型
CreateJoin(memberType.Name + "." + new ModelUtil(memberType).PrimaryKeyPropertyName); //构造多关系连接
if (!types.Contains(memberType))
{
types.Add(memberType);
}
if (expression.Expression.NodeType == ExpressionType.Parameter)
{
ResolveParameterExpression(expression.Expression as ParameterExpression);
}
else if (expression.Expression.NodeType == ExpressionType.MemberAccess)
{
ResolveMemberExpression(expression.Expression as MemberExpression);
}
expressionCatches.Add(expression.ToString(), null);
return(null);
}
else
{
//如果成员表达式的右边是值类型
var memberName = expression.Member.Name;
string RelationName = null;
if (expression.Expression.NodeType == ExpressionType.Parameter)
{
RelationName = ResolveParameterExpression(expression.Expression as ParameterExpression);
}
else if (expression.Expression.NodeType == ExpressionType.MemberAccess)
{
RelationName = (expression.Expression as MemberExpression).Type.Name;
ResolveMemberExpression(expression.Expression as MemberExpression);
}
expressionCatches.Add(expression.ToString(), RelationName + "." + memberName);
return(RelationName + "." + memberName);
}
}
else
{
return(expressionCatches[expression.ToString()]);
}
}