Ejemplo n.º 1
0
        /// <summary>
        /// Visists Join clause in case of join with local collection
        /// </summary>
        private void VisitJoinWithLocalCollectionClause(JoinClause joinClause)
        {
            var type = joinClause.InnerSequence.Type;

            var itemType = EnumerableHelper.GetIEnumerableItemType(type);

            var sqlTypeName = SqlTypes.GetSqlTypeName(itemType);

            if (string.IsNullOrWhiteSpace(sqlTypeName))
            {
                throw new NotSupportedException("Not supported item type for Join with local collection: " + type.Name);
            }

            var    isOuter            = false;
            var    sequenceExpression = joinClause.InnerSequence;
            object values;

            var subQuery = sequenceExpression as SubQueryExpression;

            if (subQuery != null)
            {
                isOuter            = subQuery.QueryModel.ResultOperators.OfType <DefaultIfEmptyResultOperator>().Any();
                sequenceExpression = subQuery.QueryModel.MainFromClause.FromExpression;
            }

            switch (sequenceExpression.NodeType)
            {
            case ExpressionType.Constant:
                var constantValueType = ((ConstantExpression)sequenceExpression).Value.GetType();
                if (constantValueType.IsGenericType)
                {
                    isOuter = DefaultIfEmptyEnumeratorType == constantValueType.GetGenericTypeDefinition();
                }
                values = ExpressionWalker.EvaluateEnumerableValues(sequenceExpression);
                break;

            case ExpressionType.Parameter:
                values = ExpressionWalker.EvaluateExpression <object>(sequenceExpression);
                break;

            default:
                throw new NotSupportedException("Expression not supported for Join with local collection: "
                                                + sequenceExpression);
            }

            var tableAlias = _aliases.GetTableAlias(joinClause);
            var fieldAlias = _aliases.GetFieldAlias(joinClause.InnerKeySelector);

            _builder.AppendFormat("{0} join table ({1} {2} = ?) {3} on (",
                                  isOuter ? "left outer" : "inner",
                                  fieldAlias,
                                  sqlTypeName,
                                  tableAlias);

            Parameters.Add(values);
        }
Ejemplo n.º 2
0
        protected override Expression VisitConditional(ConditionalExpression expression)
        {
            ResultBuilder.Append("casewhen(");

            Visit(expression.Test);

            // Explicit type specification is required when all arguments of CASEWHEN are parameters
            ResultBuilder.Append(", cast(");
            Visit(expression.IfTrue);
            ResultBuilder.AppendFormat(" as {0}), ", SqlTypes.GetSqlTypeName(expression.Type) ?? "other");

            Visit(expression.IfFalse);
            ResultBuilder.Append(')');

            return(expression);
        }