Ejemplo n.º 1
0
 public ColValue(IValueContext Context, DbColumn col)
     : base(Context)
 {
     this.col = col;
 }
Ejemplo n.º 2
0
            // _ReadNextLiteral kept for SET
            static ByteSlice _ReadNextLiteral(PartReader input, DbColumn TypeHint)
            {
                string op;

                op = input.NextPart();
                if (op.Length > 0)
                {
                    if ('\'' == op[0])
                    {
                        if (op[op.Length - 1] == '\'')
                        {
                            if ("DateTime" == TypeHint.Type.Name)
                            {
                                DateTime dt = DateTime.Parse(op.Substring(1, op.Length - 2));
                                Int64 x = dt.Ticks;
                                List<byte> buf = new List<byte>(1 + 8);
                                buf.Add(0);
                                Entry.ToBytesAppend64(x, buf);
                                return ByteSlice.Prepare(buf);
                            }
                            else
                            {
                                string str = op.Substring(1, op.Length - 2).Replace("''", "'");
                                byte[] strbytes = System.Text.Encoding.Unicode.GetBytes(str);
                                //List<byte> buf = new List<byte>(1 + strbytes.Length);
                                List<byte> buf = new List<byte>(TypeHint.Type.Size);
                                buf.Add(0);
                                buf.AddRange(strbytes);
                                // Pad up the end of the char to be the whole column size.
                                while (buf.Count < TypeHint.Type.Size)
                                {
                                    buf.Add(0);
                                }
                                return ByteSlice.Prepare(buf);
                            }
                        }
                        else
                        {
                            throw new Exception("Unterminated string: " + op);
                        }
                    }
                    else if (char.IsDigit(op[0]))
                    {
                        return ByteSlice.Prepare(_NumberLiteralToType(op, TypeHint));
                    }
                    else if ("+" == op || "-" == op)
                    {
                        bool positive = "+" == op;
                        op = input.NextPart();
                        if (0 == op.Length)
                        {
                            throw new Exception("Expected number after sign");
                        }
                        return ByteSlice.Prepare(_NumberLiteralToType(positive ? op : ("-" + op), TypeHint));
                    }
                    else
                    {
                        throw new Exception("Misunderstood value: " + op);
                    }
                }
                return ByteSlice.Prepare(new byte[] { 0 });

            }
Ejemplo n.º 3
0
 int _IndexOfRowColType(string name)
 {
     return(DbColumn.IndexOf(ColumnTypes, name));
 }
Ejemplo n.º 4
0
 int IndexOfCol(string name)
 {
     return(DbColumn.IndexOf(cols, name));
 }
Ejemplo n.º 5
0
 // _ReadNextLiteral kept for _ReadNextLiteral
 static List<byte> _NumberLiteralToType(string sNum, DbColumn ci)
 {
     List<byte> buf;
     if ("int" == ci.Type.Name)
     {
         Int32 x = Int32.Parse(sNum);
         buf = new List<byte>(1 + 4);
         buf.Add(0);
         Entry.ToBytesAppend((Int32)Entry.ToUInt32(x), buf);
     }
     else if ("long" == ci.Type.Name)
     {
         Int64 x = Int64.Parse(sNum);
         buf = new List<byte>(1 + 8);
         buf.Add(0);
         Entry.ToBytesAppend64((Int64)Entry.ToUInt64(x), buf);
     }
     else if ("double" == ci.Type.Name)
     {
         double x = double.Parse(sNum);
         buf = new List<byte>(1 + 9);
         buf.Add(0);
         recordset rs = recordset.Prepare();
         rs.PutDouble(x);
         for (int id = 0; id < 9; id++)
         {
             buf.Add(0);
         }
         rs.GetBytes(buf, 1, 9);
     }
     else
     {
         // This type isn't comparable with a number!
         buf = new List<byte>(1);
         buf.Add(1); // Nullable byte; IsNull=true;
     }
     return buf;
 }
Ejemplo n.º 6
0
            public override void Map(ByteSlice row, MapOutput output)
            {
                if (null == TableName)
                {
                    InitFields();
                }

                // Operate on values!

                ByteSlice key;

                bool keep = null == filter || filter.TestRow(row);

                if (DeleteFromFilter)
                {
                    keep = !keep;
                }

                if (keep)
                {
                    if (KeyOn != null)
                    {
                        orderbuf.Clear();
                        for (int iob = 0; iob < KeyOn.Count; iob++)
                        {
                            GetKeyPart gkp = KeyOn[iob];
                            gkp(row, orderbuf);
                        }
#if DEBUG
                        string KeyOnStringValue = "<not evaluated yet>";
                        if (0 != ((orderbuf.Count - 1) % 2))
                        {
                            KeyOnStringValue = "<not a string>";
                        }
                        else
                        {
                            //KeyOnStringValue = System.Text.Encoding.Unicode.GetString(ByteSlice.Prepare(orderbuf, 1, orderbuf.Count - 1).ToBytes());
                            {
                                System.Text.Encoding ue = new System.Text.UnicodeEncoding(false, false, true); // throwOnInvalidBytes=true
                                try
                                {
                                    KeyOnStringValue = ue.GetString(ByteSlice.Prepare(orderbuf, 1, orderbuf.Count - 1).ToBytes());
                                }
                                catch
                                {
                                    KeyOnStringValue = "<not a string>";
                                }
                            }
                        }
#endif
                        while (orderbuf.Count < DSpace_KeyLength)
                        {
                            orderbuf.Add(0);
                        }
                        key = ByteSlice.Prepare(orderbuf);
                    }
                    else // Use default key.
                    {
                        orderbuf.Clear();
                        Entry.ToBytesAppend(defkey, orderbuf);
                        key    = ByteSlice.Prepare(orderbuf);
                        defkey = unchecked (defkey + DSpace_ProcessCount);
                    }

                    if (null != Updates)
                    {
                        updatebuf.Clear();
                        row.AppendTo(updatebuf);
                        for (int ui = 0; ui < Updates.Count; ui++)
                        {
                            UpdateField uf = Updates[ui];
                            DbColumn    ci = cols[uf.FieldIndex];
                            for (int i = 0; i < ci.Type.Size; i++)
                            {
                                updatebuf[ci.RowOffset + i] = uf.NewValue[i];
                            }
                        }
                        row = ByteSlice.Prepare(updatebuf);
                    }
                }
                else
                {
                    if (null == Updates)
                    {
                        if (null != ftools)
                        {
                            ftools.ResetBuffers();
                        }

                        return;
                    }

                    if (KeyOn != null)
                    {
                        key = row;
#if DEBUG
                        throw new Exception("DEBUG:  (!keep) && (KeyOn != null)");
#endif
                    }
                    else
                    {
                        // Use default key.
                        orderbuf.Clear();
                        Entry.ToBytesAppend(defkey, orderbuf);
                        key    = ByteSlice.Prepare(orderbuf);
                        defkey = unchecked (defkey + DSpace_ProcessCount);
                    }
                }

                // If WhatFunctions, might need all input fields, so keep them here and filter out unwanted stuff in reduce.
                if (null != Whats && !WhatFunctions)
                {
                    newfieldsbuf.Clear();
                    for (int iww = 0; iww < Whats.Count; iww++)
                    {
                        int wi = Whats[iww];
                        if (-1 == wi)
                        {
                            DbTypeID ltype;
                            if (null == ftools)
                            {
                                ftools = new DbFunctionTools();
                            }
                            List <byte> lbuf = ftools.AllocBuffer();
                            ByteSlice   cval = Types.LiteralToValueBuffer(awhat[iww], out ltype, lbuf);
                            int         Size = cval.Length;
#if DEBUG
                            if (Size != OutputColumnSizes[iww])
                            {
                                throw new Exception("DEBUG:  " + awhat[iww] + ": (Size{" + Size + "} != OutputColumnSizes[iww]{" + OutputColumnSizes[iww] + "})");
                            }
#endif
                            cval.AppendTo(newfieldsbuf);
                        }
                        else
                        {
                            DbColumn ci          = cols[wi];
                            int      StartOffset = ci.RowOffset;
                            int      Size        = ci.Type.Size;
#if DEBUG
                            if (Size != OutputColumnSizes[iww])
                            {
                                throw new Exception("DEBUG:  (Size != OutputColumnSizes[iww])");
                            }
#endif
                            ByteSlice cval = ByteSlice.Prepare(row, StartOffset, Size);
                            cval.AppendTo(newfieldsbuf);
                        }
                    }
                    row = ByteSlice.Prepare(newfieldsbuf);
                }

                output.Add(key, row);

                if (null != ftools)
                {
                    ftools.ResetBuffers();
                }
            }
Ejemplo n.º 7
0
            // _ReadNextLiteral kept for SET
            static ByteSlice _ReadNextLiteral(PartReader input, DbColumn TypeHint)
            {
                string op;

                op = input.NextPart();
                if (op.Length > 0)
                {
                    if ('\'' == op[0])
                    {
                        if (op[op.Length - 1] == '\'')
                        {
                            if ("DateTime" == TypeHint.Type.Name)
                            {
                                DateTime    dt  = DateTime.Parse(op.Substring(1, op.Length - 2));
                                Int64       x   = dt.Ticks;
                                List <byte> buf = new List <byte>(1 + 8);
                                buf.Add(0);
                                Entry.ToBytesAppend64(x, buf);
                                return(ByteSlice.Prepare(buf));
                            }
                            else
                            {
                                string str      = op.Substring(1, op.Length - 2).Replace("''", "'");
                                byte[] strbytes = System.Text.Encoding.Unicode.GetBytes(str);
                                //List<byte> buf = new List<byte>(1 + strbytes.Length);
                                List <byte> buf = new List <byte>(TypeHint.Type.Size);
                                buf.Add(0);
                                buf.AddRange(strbytes);
                                // Pad up the end of the char to be the whole column size.
                                while (buf.Count < TypeHint.Type.Size)
                                {
                                    buf.Add(0);
                                }
                                return(ByteSlice.Prepare(buf));
                            }
                        }
                        else
                        {
                            throw new Exception("Unterminated string: " + op);
                        }
                    }
                    else if (char.IsDigit(op[0]))
                    {
                        return(ByteSlice.Prepare(_NumberLiteralToType(op, TypeHint)));
                    }
                    else if ("+" == op || "-" == op)
                    {
                        bool positive = "+" == op;
                        op = input.NextPart();
                        if (0 == op.Length)
                        {
                            throw new Exception("Expected number after sign");
                        }
                        return(ByteSlice.Prepare(_NumberLiteralToType(positive ? op : ("-" + op), TypeHint)));
                    }
                    else
                    {
                        throw new Exception("Misunderstood value: " + op);
                    }
                }
                return(ByteSlice.Prepare(new byte[] { 0 }));
            }
Ejemplo n.º 8
0
 void LogFieldInfo(int fieldindex, DbColumn c, bool ShouldCleanName)
 {
     string cstype = QATypeToCSType(c.Type.Name);
     string name = c.ColumnName;
     if (ShouldCleanName)
     {
         name = CleanColumnName(name);
     }
     DSpace_Log("    <field index=\"" + fieldindex.ToString() + "\" name=\"" + name + "\" qatype=\"" + c.Type.Name + "\" cstype=\"" + cstype + "\" frontbytes=\"1\" bytes=\"" + (c.Type.Size - 1).ToString() + "\" backbytes=\"0\" />");
 }
Ejemplo n.º 9
0
        CallInfo _GetSelectPartCalls(ref string calls)
        {
            CallInfo ci = new CallInfo();
            {
                string colpart = Qa.NextPart(ref calls);
                if (0 == colpart.Length)
                {
                    throw new Exception("Expected value");
                }
                if ("-" == colpart || "+" == colpart)
                {
                    colpart += Qa.NextPart(ref calls);
                }
                string s;
                s = Qa.NextPart(ref calls);
                if ("(" == s)
                {
                    List <CallInfoArg> args = new List <CallInfoArg>(4);
                    {
                        string xcalls = calls;
                        if (")" == Qa.NextPart(ref xcalls))
                        {
                            calls   = xcalls;
                            ci.func = colpart;
                            ci.args = args;
                            return(ci);
                        }
                    }
                    for (; ;)
                    {
                        CallInfo    nestci = _GetSelectPartCalls(ref calls);
                        CallInfoArg arg    = new CallInfoArg();
                        if (nestci.func == null)
                        {
#if DEBUG
                            if (1 != nestci.args.Count)
                            {
                                throw new Exception("DEBUG:  (1 != nestci.args.Count)");
                            }
#endif
                            arg = nestci.args[0];
                        }
                        else
                        {
                            arg.nest = nestci;
                        }
                        args.Add(arg);
                        s = Qa.NextPart(ref calls);
                        if (0 == string.Compare("AS", s, true))
                        {
                            arg = new CallInfoArg();
                            {
                                StringBuilder sbas     = new StringBuilder();
                                int           asparens = 0;
                                for (; ;)
                                {
                                    s = Qa.NextPart(ref calls);
                                    if (0 == s.Length || "," == s)
                                    {
                                        //calls += s;
                                        break;
                                    }
                                    else if ("(" == s)
                                    {
                                        asparens++;
                                        sbas.Append(s);
                                    }
                                    else if (")" == s)
                                    {
                                        if (0 == asparens)
                                        {
                                            //calls += s;
                                            break;
                                        }
                                        asparens--;
                                        sbas.Append(s);
                                    }
                                    else
                                    {
                                        sbas.Append(s);
                                    }
                                }
                                if (0 == sbas.Length)
                                {
                                    throw new Exception("Expected type after AS");
                                }
                                {
                                    DbValue iterval = functools.AllocValue(mstring.Prepare("AS " + sbas.ToString()));
                                    // Need to copy the value out of the functools memory
                                    // so that it survives this map/reduce iteration...
                                    DbType      xtype;
                                    ByteSlice   iterbs = iterval.Eval(out xtype);
                                    List <byte> newbuf = new List <byte>(iterbs.Length);
                                    iterbs.AppendTo(newbuf);
                                    arg.value = new ImmediateValue(null, ByteSlice.Prepare(newbuf), xtype);
                                }
                                args.Add(arg);
                            }
                            //s = Qa.NextPart(ref calls);
                        }
                        if (s == ",")
                        {
                            continue;
                        }
                        if (s == ")")
                        {
                            string xnc = calls;
                            s = Qa.NextPart(ref xnc);
                            if (0 == s.Length || "," == s || ")" == s ||
                                0 == string.Compare(s, "AS", true))
                            {
                                ci.func = colpart;
                                ci.args = args;
                                return(ci);
                            }
                            else
                            {
                                throw new Exception("Unexpected: " + s);
                            }
                            break;
                        }
                        else
                        {
                            if (s.Length != 0)
                            {
                                throw new Exception("Unexpected: " + s);
                            }
                            throw new Exception("Unexpected end of select clause");
                        }
                    }
                    // Doesn't reach here.
                }
                else
                {
                    //if (0 == s.Length || "," == s || ")" == s)
                    {
                        calls = s + " " + calls; // Undo.
                        //ci.func = null;
                        CallInfoArg arg;
                        arg = new CallInfoArg();
                        //arg.s = colpart;
                        if (colpart.Length > 0 &&
                            (char.IsLetter(colpart[0]) || '_' == colpart[0]))
                        {
                            int icol = DbColumn.IndexOf(cols, colpart);
                            if (-1 == icol)
                            {
                                throw new Exception("No such column named " + colpart);
                            }
                            arg.value = new ColValue(this, cols[icol]);
                        }
                        else
                        {
                            DbTypeID  typeid;
                            ByteSlice bs = Types.LiteralToValue(colpart, out typeid);
                            arg.value = new ImmediateValue(null, bs, DbType.Prepare(bs.Length, typeid));
                        }
                        ci.args    = new CallInfoArg[1];
                        ci.args[0] = arg;
                        return(ci);
                    }

                    /*else
                     * {
                     *  throw new Exception("Unexpected: " + s);
                     * }*/
                }
            }
        }
Ejemplo n.º 10
0
            protected override void Run()
            {
                string QlLeftTableName  = DSpace_ExecArgs[0];
                string LeftTableName    = QlArgsUnescape(QlLeftTableName);
                string stype            = DSpace_ExecArgs[1];
                string QlRightTableName = DSpace_ExecArgs[2];
                string RightTableName   = QlArgsUnescape(QlRightTableName);
                string QlOn             = DSpace_ExecArgs[3];
                string On = QlArgsUnescape(QlOn);

                if (-1 != LeftTableName.IndexOf('\0'))
                {
                    throw new NotSupportedException("Cannot JOIN with multiple left tables: " + LeftTableName);
                }

                if (-1 != RightTableName.IndexOf('\0'))
                {
                    throw new NotSupportedException("Cannot JOIN with multiple right tables: " + RightTableName);
                }

                System.Xml.XmlDocument systables;
                using (GlobalCriticalSection.GetLock())
                {
                    systables = LoadSysTables_unlocked();
                }

                System.Xml.XmlElement xeLeftTable = FindTable(systables, LeftTableName);
                if (null == xeLeftTable)
                {
                    throw new Exception("Table (left) '" + LeftTableName + "' does not exist");
                }
                string sLeftRowSize           = xeLeftTable["size"].InnerText;
                int    LeftRowSize            = int.Parse(sLeftRowSize);
                string LeftDfsTableFilesInput = xeLeftTable["file"].InnerText + "@" + sLeftRowSize;

                if (LeftDfsTableFilesInput.StartsWith("qa://", true, null))
                {
                    throw new Exception("Cannot JOIN with system tables (left)");
                }

                System.Xml.XmlElement xeRightTable = FindTable(systables, RightTableName);
                if (null == xeRightTable)
                {
                    throw new Exception("Table (right) '" + RightTableName + "' does not exist");
                }
                string sRightRowSize           = xeRightTable["size"].InnerText;
                int    RightRowSize            = int.Parse(sRightRowSize);
                string RightDfsTableFilesInput = xeRightTable["file"].InnerText + "@" + sRightRowSize;

                if (RightDfsTableFilesInput.StartsWith("qa://", true, null))
                {
                    throw new Exception("Cannot JOIN with system tables (right)");
                }

                string DfsTableFilesInput = LeftDfsTableFilesInput + ";" + RightDfsTableFilesInput;

                string DfsOutputName = "dfs://RDBMS_JoinOn_" + Guid.NewGuid().ToString() + Qa.DFS_TEMP_FILE_MARKER;

                int DfsOutputRowSize = LeftRowSize + RightRowSize;

                string          LeftRowInfo;
                string          LeftDisplayInfo; // Display
                List <DbColumn> LeftCols       = new List <DbColumn>();
                List <string>   LeftColsWidths = new List <string>();
                {
                    StringBuilder sbRowInfo     = new StringBuilder();
                    StringBuilder sbDisplayInfo = new StringBuilder(); // Display
                    int           totsize       = 0;
                    string        xtablename    = xeLeftTable["name"].InnerText;
                    foreach (System.Xml.XmlNode xn in xeLeftTable.SelectNodes("column"))
                    {
                        if (0 != sbRowInfo.Length)
                        {
                            sbRowInfo.Append('\0');
                            sbDisplayInfo.Append(','); // Display
                        }
                        string stsize      = xn["bytes"].InnerText;
                        int    tsize       = int.Parse(stsize);
                        string RealColName = xn["name"].InnerText;
                        string UserColName = RealColName;
                        string xcolname;
                        if (-1 == UserColName.IndexOf('.'))
                        {
                            xcolname = xtablename + "." + UserColName;
                        }
                        else
                        {
                            xcolname = UserColName;
                        }
                        sbRowInfo.Append(xcolname); // Note: doesn't consider sub-select.
                        sbRowInfo.Append('=');
                        sbRowInfo.Append(stsize);
                        sbDisplayInfo.Append(xn["type"].InnerText); // Display
                        sbDisplayInfo.Append('=');                  // Display
                        sbDisplayInfo.Append(xn["dw"].InnerText);   // Display
                        LeftColsWidths.Add(xn["dw"].InnerText);
                        {
                            DbColumn c;
                            c.Type       = DbType.Prepare(xn["type"].InnerText, tsize);
                            c.RowOffset  = totsize;
                            c.ColumnName = xcolname;
                            LeftCols.Add(c);
                        }
                        totsize += tsize;
                    }
                    LeftRowInfo     = sbRowInfo.ToString();
                    LeftDisplayInfo = sbDisplayInfo.ToString(); // Display
                }

                string          RightRowInfo;
                string          RightDisplayInfo; // Display
                List <DbColumn> RightCols       = new List <DbColumn>();
                List <string>   RightColsWidths = new List <string>();
                {
                    StringBuilder sbRowInfo     = new StringBuilder();
                    StringBuilder sbDisplayInfo = new StringBuilder(); // Display
                    int           totsize       = 0;
                    string        xtablename    = xeRightTable["name"].InnerText;
                    foreach (System.Xml.XmlNode xn in xeRightTable.SelectNodes("column"))
                    {
                        if (0 != sbRowInfo.Length)
                        {
                            sbRowInfo.Append('\0');
                            sbDisplayInfo.Append(','); // Display
                        }
                        string stsize      = xn["bytes"].InnerText;
                        int    tsize       = int.Parse(stsize);
                        string RealColName = xn["name"].InnerText;
                        string UserColName = RealColName;
                        string xcolname;
                        if (-1 == UserColName.IndexOf('.'))
                        {
                            xcolname = xtablename + "." + UserColName;
                        }
                        else
                        {
                            xcolname = UserColName;
                        }
                        sbRowInfo.Append(xcolname); // Note: doesn't consider sub-select.
                        sbRowInfo.Append('=');
                        sbRowInfo.Append(stsize);
                        sbDisplayInfo.Append(xn["type"].InnerText); // Display
                        sbDisplayInfo.Append('=');                  // Display
                        sbDisplayInfo.Append(xn["dw"].InnerText);   // Display
                        RightColsWidths.Add(xn["dw"].InnerText);
                        {
                            DbColumn c;
                            c.Type       = DbType.Prepare(xn["type"].InnerText, tsize);
                            c.RowOffset  = totsize;
                            c.ColumnName = xcolname;
                            RightCols.Add(c);
                        }
                        totsize += tsize;
                    }
                    RightRowInfo     = sbRowInfo.ToString();
                    RightDisplayInfo = sbDisplayInfo.ToString(); // Display
                }

                string on1, onop, on2;
                {
                    string onargs = On;
                    on1  = Qa.NextPart(ref onargs);
                    onop = Qa.NextPart(ref onargs);
                    on2  = Qa.NextPart(ref onargs);
                    if (0 == on1.Length ||
                        0 == onop.Length ||
                        0 == on2.Length ||
                        0 != onargs.Trim().Length)
                    {
                        throw new Exception("Invalid ON expression for JOIN: " + On);
                    }
                }

                bool on1left;
                int  on1colindex;
                {
                    int on1colindexother;
                    on1colindex      = DbColumn.IndexOf(LeftCols, on1);
                    on1colindexother = DbColumn.IndexOf(RightCols, on1);
                    if (-1 != on1colindex)
                    {
                        if (-1 != on1colindexother)
                        {
                            throw new Exception("Column name " + on1 + " does not resolve to a single column (in left and right tables)");
                        }
                        else
                        {
                            on1left = true;
                        }
                    }
                    else
                    {
                        if (-1 != on1colindexother)
                        {
                            on1colindex = on1colindexother;
                            on1left     = false;
                        }
                        else
                        {
                            throw new Exception("No such column named " + on1);
                        }
                    }
                }

                bool on2left;
                int  on2colindex;

                {
                    int on2colindexother;
                    on2colindex      = DbColumn.IndexOf(LeftCols, on2);
                    on2colindexother = DbColumn.IndexOf(RightCols, on2);
                    if (-1 != on2colindex)
                    {
                        if (-1 != on2colindexother)
                        {
                            throw new Exception("Column name " + on2 + " does not resolve to a single column (in left and right tables)");
                        }
                        else
                        {
                            on2left = true;
                        }
                    }
                    else
                    {
                        if (-1 != on2colindexother)
                        {
                            on2colindex = on2colindexother;
                            on2left     = false;
                        }
                        else
                        {
                            throw new Exception("No such column named " + on2);
                        }
                    }
                }

                if ((on1left && on2left) ||
                    (!on1left && !on2left))
                {
                    string whicht;
                    if (on1left)
                    {
                        whicht = "(left) " + LeftTableName;
                    }
                    else
                    {
                        whicht = "(right) " + RightTableName;
                    }
                    throw new Exception("ON expression is comparing columns from the same table: "
                                        + on1 + " and " + on2 + " are both part of " + whicht);
                }

                // Order ON columns:
                if (!on1left)
                {
                    {
                        string onx = on1;
                        on1 = on2;
                        on2 = onx;
                    }
                    {
                        int onxcolindex = on1colindex;
                        on1colindex = on2colindex;
                        on2colindex = onxcolindex;
                    }
                    {
                        on1left = true;
                        on2left = false;
                    }
                    // Invert the operator..
                    switch (onop)
                    {
                    case "=":
                        //onop = "=";
                        break;

                    case "!=":
                        //onop = "!=";
                        break;

                    case "<":
                        onop = ">";
                        break;

                    case "<=":
                        onop = ">=";
                        break;

                    case ">":
                        onop = "<";
                        break;

                    case ">=":
                        onop = "<=";
                        break;

                    default:
                        throw new Exception("Unhandled ON operation: " + onop);
                    }
                    On   = on1 + " " + onop + " " + on2;
                    QlOn = QlArgsEscape(On);
                }

                DbColumn on1col;

                if (on1left)
                {
                    on1col = LeftCols[on1colindex];
                }
                else
                {
                    //on1col = RightCols[on1colindex];
                    throw new Exception("DEBUG:  PrepareJoinOn: (!on1left)");
                }
                if (on1col.Type.Size == 0 || on1col.Type.ID == DbTypeID.NULL)
                {
                    throw new Exception("Invalid column for ON expression: " + on1);
                }

                DbColumn on2col;

                if (on2left)
                {
                    //on2col = LeftCols[on2colindex];
                    throw new Exception("DEBUG:  PrepareJoinOn: (on2left)");
                }
                else
                {
                    on2col = RightCols[on2colindex];
                }
                if (on2col.Type.Size == 0 || on2col.Type.ID == DbTypeID.NULL)
                {
                    throw new Exception("Invalid column for ON expression: " + on2);
                }

                int KeyLength = on1col.Type.Size;

                if (on2col.Type.Size > KeyLength)
                {
                    KeyLength = on2col.Type.Size;
                }

                {
                    MapReduceCall mrc = GetMapReduceCallJoinOn(DfsTableFilesInput);
                    mrc.OverrideOutputMethod = "grouped";
                    mrc.OverrideInput        = DfsTableFilesInput;
                    mrc.OverrideOutput       = DfsOutputName + "@" + DfsOutputRowSize;
                    mrc.OverrideKeyLength    = KeyLength;
                    if (RDBMS_DBCORE.Qa.FaultTolerantExecution)
                    {
                        mrc.OverrideFaultTolerantExecutionMode = "enabled";
                    }
                    mrc.Call("\"" + QlLeftTableName + "\" " + stype + " \"" + QlRightTableName
                             + "\" \"" + QlOn
                             + "\" \"" + on1col.RowOffset + "," + on1col.Type.Size + "=" + QlArgsEscape(on1col.Type.Name)
                             + "\" \"" + on2col.RowOffset + "," + on2col.Type.Size + "=" + QlArgsEscape(on2col.Type.Name)
                             + "\" \"" + DfsTableFilesInput
                             + "\"");
                }

                {
                    PrepareSelect.queryresults qr      = new PrepareSelect.queryresults();
                    List <DbColumn>            AllCols = new List <DbColumn>(LeftCols.Count + RightCols.Count);
                    AllCols.AddRange(LeftCols);
                    AllCols.AddRange(RightCols);
                    qr.SetFields(AllCols);
                    qr.temptable  = DfsOutputName;
                    qr.recordsize = LeftRowSize + RightRowSize;
                    string sPartCount = Shell("dspace countparts \"" + DfsOutputName + "\"").Split('\n')[0].Trim();
                    qr.parts = int.Parse(sPartCount);
                    string sDfsOutputSize = Shell("dspace filesize \"" + DfsOutputName + "\"").Split('\n')[0].Trim();
                    long   DfsOutputSize  = long.Parse(sDfsOutputSize);
                    long   NumRowsOutput  = DfsOutputSize / qr.recordsize;
                    qr.recordcount = NumRowsOutput;

                    DSpace_Log(PrepareSelect.SetQueryResults(qr));
                }
            }