internal override SqlExpression VisitOptionalValue(SqlOptionalValue sov)
            {
                SqlExpression hasValue = this.VisitExpression(sov.HasValue);
                SqlExpression value    = this.VisitExpression(sov.Value);

                return(new SqlOptionalValue(hasValue, value));
            }
Пример #2
0
            internal override SqlExpression VisitOptionalValue(SqlOptionalValue sov)
            {
                bool saveCanJoin = this.canJoin;

                this.canJoin = false;
                try {
                    return(base.VisitOptionalValue(sov));
                }
                finally {
                    this.canJoin = saveCanJoin;
                }
            }
Пример #3
0
            private void FlattenGroupByExpression(List <SqlExpression> exprs, SqlExpression expr)
            {
                SqlNew sn = expr as SqlNew;

                if (sn != null)
                {
                    foreach (SqlMemberAssign ma in sn.Members)
                    {
                        this.FlattenGroupByExpression(exprs, ma.Expression);
                    }
                    foreach (SqlExpression arg in sn.Args)
                    {
                        this.FlattenGroupByExpression(exprs, arg);
                    }
                }
                else if (expr.NodeType == SqlNodeType.TypeCase)
                {
                    SqlTypeCase tc = (SqlTypeCase)expr;
                    this.FlattenGroupByExpression(exprs, tc.Discriminator);
                    foreach (SqlTypeCaseWhen when in tc.Whens)
                    {
                        this.FlattenGroupByExpression(exprs, when.TypeBinding);
                    }
                }
                else if (expr.NodeType == SqlNodeType.Link)
                {
                    SqlLink link = (SqlLink)expr;
                    if (link.Expansion != null)
                    {
                        this.FlattenGroupByExpression(exprs, link.Expansion);
                    }
                    else
                    {
                        foreach (SqlExpression key in link.KeyExpressions)
                        {
                            this.FlattenGroupByExpression(exprs, key);
                        }
                    }
                }
                else if (expr.NodeType == SqlNodeType.OptionalValue)
                {
                    SqlOptionalValue sop = (SqlOptionalValue)expr;
                    this.FlattenGroupByExpression(exprs, sop.HasValue);
                    this.FlattenGroupByExpression(exprs, sop.Value);
                }
                else if (expr.NodeType == SqlNodeType.OuterJoinedValue)
                {
                    this.FlattenGroupByExpression(exprs, ((SqlUnary)expr).Operand);
                }
                else if (expr.NodeType == SqlNodeType.DiscriminatedType)
                {
                    SqlDiscriminatedType dt = (SqlDiscriminatedType)expr;
                    this.FlattenGroupByExpression(exprs, dt.Discriminator);
                }
                else
                {
                    // this expression should have been 'pushed-down' in SqlBinder, so we
                    // should only find column-references & expr-sets unless the expression could not
                    // be columnized (in which case it was a bad group-by expression.)
                    if (expr.NodeType != SqlNodeType.ColumnRef &&
                        expr.NodeType != SqlNodeType.ExprSet)
                    {
                        if (!expr.SqlType.CanBeColumn)
                        {
                            throw Error.InvalidGroupByExpressionType(expr.SqlType.ToQueryString());
                        }
                        throw Error.InvalidGroupByExpression();
                    }
                    exprs.Add(expr);
                }
            }
Пример #4
0
 internal virtual SqlExpression VisitOptionalValue(SqlOptionalValue sov)
 {
     sov.HasValue = this.VisitExpression(sov.HasValue);
     sov.Value    = this.VisitExpression(sov.Value);
     return(sov);
 }
Пример #5
0
        internal static bool AreEqual(SqlNode node1, SqlNode node2)
        {
            if (node1 == node2)
            {
                return(true);
            }
            if (node1 == null || node2 == null)
            {
                return(false);
            }

            if (node1.NodeType == SqlNodeType.SimpleCase)
            {
                node1 = UnwrapTrivialCaseExpression((SqlSimpleCase)node1);
            }

            if (node2.NodeType == SqlNodeType.SimpleCase)
            {
                node2 = UnwrapTrivialCaseExpression((SqlSimpleCase)node2);
            }

            if (node1.NodeType != node2.NodeType)
            {
                // allow expression sets to compare against single expressions
                if (node1.NodeType == SqlNodeType.ExprSet)
                {
                    SqlExprSet eset = (SqlExprSet)node1;
                    for (int i = 0, n = eset.Expressions.Count; i < n; i++)
                    {
                        if (AreEqual(eset.Expressions[i], node2))
                        {
                            return(true);
                        }
                    }
                }
                else if (node2.NodeType == SqlNodeType.ExprSet)
                {
                    SqlExprSet eset = (SqlExprSet)node2;
                    for (int i = 0, n = eset.Expressions.Count; i < n; i++)
                    {
                        if (AreEqual(node1, eset.Expressions[i]))
                        {
                            return(true);
                        }
                    }
                }
                return(false);
            }
            if (node1.Equals(node2))
            {
                return(true);
            }

            switch (node1.NodeType)
            {
            case SqlNodeType.Not:
            case SqlNodeType.Not2V:
            case SqlNodeType.Negate:
            case SqlNodeType.BitNot:
            case SqlNodeType.IsNull:
            case SqlNodeType.IsNotNull:
            case SqlNodeType.Count:
            case SqlNodeType.Max:
            case SqlNodeType.Min:
            case SqlNodeType.Sum:
            case SqlNodeType.Avg:
            case SqlNodeType.Stddev:
            case SqlNodeType.ValueOf:
            case SqlNodeType.OuterJoinedValue:
            case SqlNodeType.ClrLength:
                return(AreEqual(((SqlUnary)node1).Operand, ((SqlUnary)node2).Operand));

            case SqlNodeType.Add:
            case SqlNodeType.Sub:
            case SqlNodeType.Mul:
            case SqlNodeType.Div:
            case SqlNodeType.Mod:
            case SqlNodeType.BitAnd:
            case SqlNodeType.BitOr:
            case SqlNodeType.BitXor:
            case SqlNodeType.And:
            case SqlNodeType.Or:
            case SqlNodeType.GE:
            case SqlNodeType.GT:
            case SqlNodeType.LE:
            case SqlNodeType.LT:
            case SqlNodeType.EQ:
            case SqlNodeType.NE:
            case SqlNodeType.EQ2V:
            case SqlNodeType.NE2V:
            case SqlNodeType.Concat:
                SqlBinary firstNode  = (SqlBinary)node1;
                SqlBinary secondNode = (SqlBinary)node2;
                return(AreEqual(firstNode.Left, secondNode.Left) &&
                       AreEqual(firstNode.Right, secondNode.Right));

            case SqlNodeType.Convert:
            case SqlNodeType.Treat: {
                SqlUnary sun1 = (SqlUnary)node1;
                SqlUnary sun2 = (SqlUnary)node2;
                return(sun1.ClrType == sun2.ClrType && sun1.SqlType == sun2.SqlType && AreEqual(sun1.Operand, sun2.Operand));
            }

            case SqlNodeType.Between: {
                SqlBetween b1 = (SqlBetween)node1;
                SqlBetween b2 = (SqlBetween)node1;
                return(AreEqual(b1.Expression, b2.Expression) &&
                       AreEqual(b1.Start, b2.Start) &&
                       AreEqual(b1.End, b2.End));
            }

            case SqlNodeType.Parameter:
                return(node1 == node2);

            case SqlNodeType.Alias:
                return(AreEqual(((SqlAlias)node1).Node, ((SqlAlias)node2).Node));

            case SqlNodeType.AliasRef:
                return(AreEqual(((SqlAliasRef)node1).Alias, ((SqlAliasRef)node2).Alias));

            case SqlNodeType.Column:
                SqlColumn col1 = (SqlColumn)node1;
                SqlColumn col2 = (SqlColumn)node2;
                return(col1 == col2 || (col1.Expression != null && col2.Expression != null && AreEqual(col1.Expression, col2.Expression)));

            case SqlNodeType.Table:
                return(((SqlTable)node1).MetaTable == ((SqlTable)node2).MetaTable);

            case SqlNodeType.Member:
                return((((SqlMember)node1).Member == ((SqlMember)node2).Member) &&
                       AreEqual(((SqlMember)node1).Expression, ((SqlMember)node2).Expression));

            case SqlNodeType.ColumnRef:
                SqlColumnRef cref1 = (SqlColumnRef)node1;
                SqlColumnRef cref2 = (SqlColumnRef)node2;
                return(GetBaseColumn(cref1) == GetBaseColumn(cref2));

            case SqlNodeType.Value:
                return(Object.Equals(((SqlValue)node1).Value, ((SqlValue)node2).Value));

            case SqlNodeType.TypeCase: {
                SqlTypeCase c1 = (SqlTypeCase)node1;
                SqlTypeCase c2 = (SqlTypeCase)node2;
                if (!AreEqual(c1.Discriminator, c2.Discriminator))
                {
                    return(false);
                }
                if (c1.Whens.Count != c2.Whens.Count)
                {
                    return(false);
                }
                for (int i = 0, c = c1.Whens.Count; i < c; ++i)
                {
                    if (!AreEqual(c1.Whens[i].Match, c2.Whens[i].Match))
                    {
                        return(false);
                    }
                    if (!AreEqual(c1.Whens[i].TypeBinding, c2.Whens[i].TypeBinding))
                    {
                        return(false);
                    }
                }

                return(true);
            }

            case SqlNodeType.SearchedCase: {
                SqlSearchedCase c1 = (SqlSearchedCase)node1;
                SqlSearchedCase c2 = (SqlSearchedCase)node2;
                if (c1.Whens.Count != c2.Whens.Count)
                {
                    return(false);
                }
                for (int i = 0, n = c1.Whens.Count; i < n; i++)
                {
                    if (!AreEqual(c1.Whens[i].Match, c2.Whens[i].Match) ||
                        !AreEqual(c1.Whens[i].Value, c2.Whens[i].Value))
                    {
                        return(false);
                    }
                }
                return(AreEqual(c1.Else, c2.Else));
            }

            case SqlNodeType.ClientCase: {
                SqlClientCase c1 = (SqlClientCase)node1;
                SqlClientCase c2 = (SqlClientCase)node2;
                if (c1.Whens.Count != c2.Whens.Count)
                {
                    return(false);
                }
                for (int i = 0, n = c1.Whens.Count; i < n; i++)
                {
                    if (!AreEqual(c1.Whens[i].Match, c2.Whens[i].Match) ||
                        !AreEqual(c1.Whens[i].Value, c2.Whens[i].Value))
                    {
                        return(false);
                    }
                }
                return(true);
            }

            case SqlNodeType.DiscriminatedType: {
                SqlDiscriminatedType dt1 = (SqlDiscriminatedType)node1;
                SqlDiscriminatedType dt2 = (SqlDiscriminatedType)node2;
                return(AreEqual(dt1.Discriminator, dt2.Discriminator));
            }

            case SqlNodeType.SimpleCase: {
                SqlSimpleCase c1 = (SqlSimpleCase)node1;
                SqlSimpleCase c2 = (SqlSimpleCase)node2;
                if (c1.Whens.Count != c2.Whens.Count)
                {
                    return(false);
                }
                for (int i = 0, n = c1.Whens.Count; i < n; i++)
                {
                    if (!AreEqual(c1.Whens[i].Match, c2.Whens[i].Match) ||
                        !AreEqual(c1.Whens[i].Value, c2.Whens[i].Value))
                    {
                        return(false);
                    }
                }
                return(true);
            }

            case SqlNodeType.Like: {
                SqlLike like1 = (SqlLike)node1;
                SqlLike like2 = (SqlLike)node2;
                return(AreEqual(like1.Expression, like2.Expression) &&
                       AreEqual(like1.Pattern, like2.Pattern) &&
                       AreEqual(like1.Escape, like2.Escape));
            }

            case SqlNodeType.Variable: {
                SqlVariable v1 = (SqlVariable)node1;
                SqlVariable v2 = (SqlVariable)node2;
                return(v1.Name == v2.Name);
            }

            case SqlNodeType.FunctionCall: {
                SqlFunctionCall f1 = (SqlFunctionCall)node1;
                SqlFunctionCall f2 = (SqlFunctionCall)node2;
                if (f1.Name != f2.Name)
                {
                    return(false);
                }
                if (f1.Arguments.Count != f2.Arguments.Count)
                {
                    return(false);
                }
                for (int i = 0, n = f1.Arguments.Count; i < n; i++)
                {
                    if (!AreEqual(f1.Arguments[i], f2.Arguments[i]))
                    {
                        return(false);
                    }
                }
                return(true);
            }

            case SqlNodeType.Link: {
                SqlLink l1 = (SqlLink)node1;
                SqlLink l2 = (SqlLink)node2;
                if (!MetaPosition.AreSameMember(l1.Member.Member, l2.Member.Member))
                {
                    return(false);
                }
                if (!AreEqual(l1.Expansion, l2.Expansion))
                {
                    return(false);
                }
                if (l1.KeyExpressions.Count != l2.KeyExpressions.Count)
                {
                    return(false);
                }
                for (int i = 0, c = l1.KeyExpressions.Count; i < c; ++i)
                {
                    if (!AreEqual(l1.KeyExpressions[i], l2.KeyExpressions[i]))
                    {
                        return(false);
                    }
                }
                return(true);
            }

            case SqlNodeType.ExprSet:
                SqlExprSet es1 = (SqlExprSet)node1;
                SqlExprSet es2 = (SqlExprSet)node2;
                if (es1.Expressions.Count != es2.Expressions.Count)
                {
                    return(false);
                }
                for (int i = 0, n = es1.Expressions.Count; i < n; i++)
                {
                    if (!AreEqual(es1.Expressions[i], es2.Expressions[i]))
                    {
                        return(false);
                    }
                }
                return(true);

            case SqlNodeType.OptionalValue:
                SqlOptionalValue ov1 = (SqlOptionalValue)node1;
                SqlOptionalValue ov2 = (SqlOptionalValue)node2;
                return(AreEqual(ov1.Value, ov2.Value));

            case SqlNodeType.Row:
            case SqlNodeType.UserQuery:
            case SqlNodeType.StoredProcedureCall:
            case SqlNodeType.UserRow:
            case SqlNodeType.UserColumn:
            case SqlNodeType.Multiset:
            case SqlNodeType.ScalarSubSelect:
            case SqlNodeType.Element:
            case SqlNodeType.Exists:
            case SqlNodeType.Join:
            case SqlNodeType.Select:
            case SqlNodeType.New:
            case SqlNodeType.ClientQuery:
            case SqlNodeType.ClientArray:
            case SqlNodeType.Insert:
            case SqlNodeType.Update:
            case SqlNodeType.Delete:
            case SqlNodeType.MemberAssign:
            case SqlNodeType.Assign:
            case SqlNodeType.Block:
            case SqlNodeType.Union:
            case SqlNodeType.DoNotVisit:
            case SqlNodeType.MethodCall:
            case SqlNodeType.Nop:
            default:
                return(false);
            }
        }
Пример #6
0
            private SqlExpression ExpandTogether(List <SqlExpression> exprs)
            {
                switch (exprs[0].NodeType)
                {
                case SqlNodeType.MethodCall: {
                    SqlMethodCall[] mcs = new SqlMethodCall[exprs.Count];
                    for (int i = 0; i < mcs.Length; ++i)
                    {
                        mcs[i] = (SqlMethodCall)exprs[i];
                    }

                    List <SqlExpression> expandedArgs = new List <SqlExpression>();

                    for (int i = 0; i < mcs[0].Arguments.Count; ++i)
                    {
                        List <SqlExpression> args = new List <SqlExpression>();
                        for (int j = 0; j < mcs.Length; ++j)
                        {
                            args.Add(mcs[j].Arguments[i]);
                        }
                        SqlExpression expanded = this.ExpandTogether(args);
                        expandedArgs.Add(expanded);
                    }
                    return(factory.MethodCall(mcs[0].Method, mcs[0].Object, expandedArgs.ToArray(), mcs[0].SourceExpression));
                }

                case SqlNodeType.ClientCase: {
                    // Are they all the same?
                    SqlClientCase[] scs = new SqlClientCase[exprs.Count];
                    scs[0] = (SqlClientCase)exprs[0];
                    for (int i = 1; i < scs.Length; ++i)
                    {
                        scs[i] = (SqlClientCase)exprs[i];
                    }

                    // Expand expressions together.
                    List <SqlExpression> expressions = new List <SqlExpression>();
                    for (int i = 0; i < scs.Length; ++i)
                    {
                        expressions.Add(scs[i].Expression);
                    }
                    SqlExpression expression = this.ExpandTogether(expressions);

                    // Expand individual expressions together.
                    List <SqlClientWhen> whens = new List <SqlClientWhen>();
                    for (int i = 0; i < scs[0].Whens.Count; ++i)
                    {
                        List <SqlExpression> scos = new List <SqlExpression>();
                        for (int j = 0; j < scs.Length; ++j)
                        {
                            SqlClientWhen when = scs[j].Whens[i];
                            scos.Add(when.Value);
                        }
                        whens.Add(new SqlClientWhen(scs[0].Whens[i].Match, this.ExpandTogether(scos)));
                    }

                    return(new SqlClientCase(scs[0].ClrType, expression, whens, scs[0].SourceExpression));
                }

                case SqlNodeType.TypeCase: {
                    // Are they all the same?
                    SqlTypeCase[] tcs = new SqlTypeCase[exprs.Count];
                    tcs[0] = (SqlTypeCase)exprs[0];
                    for (int i = 1; i < tcs.Length; ++i)
                    {
                        tcs[i] = (SqlTypeCase)exprs[i];
                    }

                    // Expand discriminators together.
                    List <SqlExpression> discriminators = new List <SqlExpression>();
                    for (int i = 0; i < tcs.Length; ++i)
                    {
                        discriminators.Add(tcs[i].Discriminator);
                    }
                    SqlExpression discriminator = this.ExpandTogether(discriminators);
                    // Write expanded discriminators back in.
                    for (int i = 0; i < tcs.Length; ++i)
                    {
                        tcs[i].Discriminator = discriminators[i];
                    }
                    // Expand individual type bindings together.
                    List <SqlTypeCaseWhen> whens = new List <SqlTypeCaseWhen>();
                    for (int i = 0; i < tcs[0].Whens.Count; ++i)
                    {
                        List <SqlExpression> scos = new List <SqlExpression>();
                        for (int j = 0; j < tcs.Length; ++j)
                        {
                            SqlTypeCaseWhen when = tcs[j].Whens[i];
                            scos.Add(when.TypeBinding);
                        }
                        SqlExpression expanded = this.ExpandTogether(scos);
                        whens.Add(new SqlTypeCaseWhen(tcs[0].Whens[i].Match, expanded));
                    }

                    return(factory.TypeCase(tcs[0].ClrType, tcs[0].RowType, discriminator, whens, tcs[0].SourceExpression));
                }

                case SqlNodeType.New: {
                    // first verify all are similar client objects...
                    SqlNew[] cobs = new SqlNew[exprs.Count];
                    cobs[0] = (SqlNew)exprs[0];
                    for (int i = 1, n = exprs.Count; i < n; i++)
                    {
                        if (exprs[i] == null || exprs[i].NodeType != SqlNodeType.New)
                        {
                            throw Error.UnionIncompatibleConstruction();
                        }
                        cobs[i] = (SqlNew)exprs[1];
                        if (cobs[i].Members.Count != cobs[0].Members.Count)
                        {
                            throw Error.UnionDifferentMembers();
                        }
                        for (int m = 0, mn = cobs[0].Members.Count; m < mn; m++)
                        {
                            if (cobs[i].Members[m].Member != cobs[0].Members[m].Member)
                            {
                                throw Error.UnionDifferentMemberOrder();
                            }
                        }
                    }
                    SqlMemberAssign[] bindings = new SqlMemberAssign[cobs[0].Members.Count];
                    for (int m = 0, mn = bindings.Length; m < mn; m++)
                    {
                        List <SqlExpression> mexprs = new List <SqlExpression>();
                        for (int i = 0, n = exprs.Count; i < n; i++)
                        {
                            mexprs.Add(cobs[i].Members[m].Expression);
                        }
                        bindings[m] = new SqlMemberAssign(cobs[0].Members[m].Member, this.ExpandTogether(mexprs));
                        for (int i = 0, n = exprs.Count; i < n; i++)
                        {
                            cobs[i].Members[m].Expression = mexprs[i];
                        }
                    }
                    SqlExpression[] arguments = new SqlExpression[cobs[0].Args.Count];
                    for (int m = 0, mn = arguments.Length; m < mn; ++m)
                    {
                        List <SqlExpression> mexprs = new List <SqlExpression>();
                        for (int i = 0, n = exprs.Count; i < n; i++)
                        {
                            mexprs.Add(cobs[i].Args[m]);
                        }
                        arguments[m] = ExpandTogether(mexprs);
                    }
                    return(factory.New(cobs[0].MetaType, cobs[0].Constructor, arguments, cobs[0].ArgMembers, bindings, exprs[0].SourceExpression));
                }

                case SqlNodeType.Link: {
                    SqlLink[] links = new SqlLink[exprs.Count];
                    links[0] = (SqlLink)exprs[0];
                    for (int i = 1, n = exprs.Count; i < n; i++)
                    {
                        if (exprs[i] == null || exprs[i].NodeType != SqlNodeType.Link)
                        {
                            throw Error.UnionIncompatibleConstruction();
                        }
                        links[i] = (SqlLink)exprs[i];
                        if (links[i].KeyExpressions.Count != links[0].KeyExpressions.Count ||
                            links[i].Member != links[0].Member ||
                            (links[i].Expansion != null) != (links[0].Expansion != null))
                        {
                            throw Error.UnionIncompatibleConstruction();
                        }
                    }
                    SqlExpression[]      kexprs = new SqlExpression[links[0].KeyExpressions.Count];
                    List <SqlExpression> lexprs = new List <SqlExpression>();
                    for (int k = 0, nk = links[0].KeyExpressions.Count; k < nk; k++)
                    {
                        lexprs.Clear();
                        for (int i = 0, n = exprs.Count; i < n; i++)
                        {
                            lexprs.Add(links[i].KeyExpressions[k]);
                        }
                        kexprs[k] = this.ExpandTogether(lexprs);
                        for (int i = 0, n = exprs.Count; i < n; i++)
                        {
                            links[i].KeyExpressions[k] = lexprs[i];
                        }
                    }
                    SqlExpression expansion = null;
                    if (links[0].Expansion != null)
                    {
                        lexprs.Clear();
                        for (int i = 0, n = exprs.Count; i < n; i++)
                        {
                            lexprs.Add(links[i].Expansion);
                        }
                        expansion = this.ExpandTogether(lexprs);
                        for (int i = 0, n = exprs.Count; i < n; i++)
                        {
                            links[i].Expansion = lexprs[i];
                        }
                    }
                    return(new SqlLink(links[0].Id, links[0].RowType, links[0].ClrType, links[0].SqlType, links[0].Expression, links[0].Member, kexprs, expansion, links[0].SourceExpression));
                }

                case SqlNodeType.Value: {
                    /*
                     * ExprSet of all literals of the same value reduce to just a single literal.
                     */
                    SqlValue val0 = (SqlValue)exprs[0];
                    for (int i = 1; i < exprs.Count; ++i)
                    {
                        SqlValue val = (SqlValue)exprs[i];
                        if (!object.Equals(val.Value, val0.Value))
                        {
                            return(this.ExpandIntoExprSet(exprs));
                        }
                    }
                    return(val0);
                }

                case SqlNodeType.OptionalValue: {
                    if (exprs[0].SqlType.CanBeColumn)
                    {
                        goto default;
                    }
                    List <SqlExpression> hvals = new List <SqlExpression>(exprs.Count);
                    List <SqlExpression> vals  = new List <SqlExpression>(exprs.Count);
                    for (int i = 0, n = exprs.Count; i < n; i++)
                    {
                        if (exprs[i] == null || exprs[i].NodeType != SqlNodeType.OptionalValue)
                        {
                            throw Error.UnionIncompatibleConstruction();
                        }
                        SqlOptionalValue sov = (SqlOptionalValue)exprs[i];
                        hvals.Add(sov.HasValue);
                        vals.Add(sov.Value);
                    }
                    return(new SqlOptionalValue(this.ExpandTogether(hvals), this.ExpandTogether(vals)));
                }

                case SqlNodeType.OuterJoinedValue: {
                    if (exprs[0].SqlType.CanBeColumn)
                    {
                        goto default;
                    }
                    List <SqlExpression> values = new List <SqlExpression>(exprs.Count);
                    for (int i = 0, n = exprs.Count; i < n; i++)
                    {
                        if (exprs[i] == null || exprs[i].NodeType != SqlNodeType.OuterJoinedValue)
                        {
                            throw Error.UnionIncompatibleConstruction();
                        }
                        SqlUnary su = (SqlUnary)exprs[i];
                        values.Add(su.Operand);
                    }
                    return(factory.Unary(SqlNodeType.OuterJoinedValue, this.ExpandTogether(values)));
                }

                case SqlNodeType.DiscriminatedType: {
                    SqlDiscriminatedType sdt0 = (SqlDiscriminatedType)exprs[0];
                    List <SqlExpression> foos = new List <SqlExpression>(exprs.Count);
                    foos.Add(sdt0.Discriminator);
                    for (int i = 1, n = exprs.Count; i < n; i++)
                    {
                        SqlDiscriminatedType sdtN = (SqlDiscriminatedType)exprs[i];
                        if (sdtN.TargetType != sdt0.TargetType)
                        {
                            throw Error.UnionIncompatibleConstruction();
                        }
                        foos.Add(sdtN.Discriminator);
                    }
                    return(factory.DiscriminatedType(this.ExpandTogether(foos), ((SqlDiscriminatedType)exprs[0]).TargetType));
                }

                case SqlNodeType.ClientQuery:
                case SqlNodeType.Multiset:
                case SqlNodeType.Element:
                case SqlNodeType.Grouping:
                    throw Error.UnionWithHierarchy();

                default:
                    return(this.ExpandIntoExprSet(exprs));
                }
            }
 internal override SqlExpression VisitOptionalValue(SqlOptionalValue sov)
 {
     sov.HasValue = this.VisitNamedExpression(sov.HasValue, "test");
     sov.Value    = this.VisitExpression(sov.Value);
     return(sov);
 }