public virtual GeneralQueryState AsSubQueryState()
{
DbSqlQueryExpression sqlQuery = this.CreateSqlQuery();
DbSubQueryExpression subQuery = new DbSubQueryExpression(sqlQuery);
ResultElement result = new ResultElement();
DbTableSegment tableSeg = new DbTableSegment(subQuery, result.GenerateUniqueTableAlias());
DbFromTableExpression fromTable = new DbFromTableExpression(tableSeg);
result.FromTable = fromTable;
DbTable table = new DbTable(tableSeg.Alias);
//TODO 根据旧的生成新 MappingMembers
IMappingObjectExpression newMoe = this.Result.MappingObjectExpression.ToNewObjectExpression(sqlQuery, table);
result.MappingObjectExpression = newMoe;
//得将 subQuery.SqlQuery.Orders 告诉 以下创建的 result
//将 orderPart 传递下去
if (this.Result.OrderSegments.Count > 0)
{
for (int i = 0; i < this.Result.OrderSegments.Count; i++)
{
DbOrderSegment orderPart = this.Result.OrderSegments[i];
DbExpression orderExp = orderPart.DbExpression;
string alias = null;
DbColumnSegment columnExpression = sqlQuery.ColumnSegments.Where(a => DbExpressionEqualityComparer.EqualsCompare(orderExp, a.Body)).FirstOrDefault();
// 对于重复的则不需要往 sqlQuery.Columns 重复添加了
if (columnExpression != null)
{
alias = columnExpression.Alias;
}
else
{
alias = Utils.GenerateUniqueColumnAlias(sqlQuery);
DbColumnSegment columnSeg = new DbColumnSegment(orderExp, alias);
sqlQuery.ColumnSegments.Add(columnSeg);
}
DbColumnAccessExpression columnAccessExpression = new DbColumnAccessExpression(orderExp.Type, table, alias);
result.OrderSegments.Add(new DbOrderSegment(columnAccessExpression, orderPart.OrderType));
}
}
result.IsOrderSegmentsFromSubQuery = true;
GeneralQueryState queryState = new GeneralQueryState(result);
return(queryState);
}
protected static DbOrderSegment VisistOrderExpression(List <IMappingObjectExpression> moeList, OrderExpression orderExp)
{
DbExpression dbExpression = GeneralExpressionVisitor.VisitPredicate(orderExp.Expression, moeList);
OrderType orderType;
if (orderExp.NodeType == QueryExpressionType.OrderBy || orderExp.NodeType == QueryExpressionType.ThenBy)
{
orderType = OrderType.Asc;
}
else if (orderExp.NodeType == QueryExpressionType.OrderByDesc || orderExp.NodeType == QueryExpressionType.ThenByDesc)
{
orderType = OrderType.Desc;
}
else
{
throw new NotSupportedException(orderExp.NodeType.ToString());
}
DbOrderSegment orderSeg = new DbOrderSegment(dbExpression, orderType);
return(orderSeg);
}
protected static DbOrderSegment VisistOrderExpression(List<IMappingObjectExpression> moeList, OrderExpression orderExp)
{
DbExpression dbExpression = GeneralExpressionVisitor.VisitPredicate(orderExp.Expression, moeList);
OrderType orderType;
if (orderExp.NodeType == QueryExpressionType.OrderBy || orderExp.NodeType == QueryExpressionType.ThenBy)
{
orderType = OrderType.Asc;
}
else if (orderExp.NodeType == QueryExpressionType.OrderByDesc || orderExp.NodeType == QueryExpressionType.ThenByDesc)
{
orderType = OrderType.Desc;
}
else
throw new NotSupportedException(orderExp.NodeType.ToString());
DbOrderSegment orderSeg = new DbOrderSegment(dbExpression, orderType);
return orderSeg;
}