C# DbFunctionTools.AllocNullValue方法代碼示例

本文整理匯總了C#中RDBMS_DBCORE.DbFunctionTools.AllocNullValue方法的典型用法代碼示例。如果您正苦於以下問題：C# DbFunctionTools.AllocNullValue方法的具體用法？C# DbFunctionTools.AllocNullValue怎麽用？C# DbFunctionTools.AllocNullValue使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類RDBMS_DBCORE.DbFunctionTools的用法示例。

在下文中一共展示了DbFunctionTools.AllocNullValue方法的15個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的C#代碼示例。

示例1: INSTR

        public static DbValue INSTR(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "INSTR";

            args.EnsureMinCount(FunctionName, 2);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg0type.Name.ToUpper());
            }

            DbType arg1type;
            ByteSlice arg1 = args[1].Eval(out arg1type);
            if (Types.IsNullValue(arg1))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg1type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg1type.Name.ToUpper());
            }

            int startIndex = 0;
            if (args.Length > 2)
            {
                DbType arg2type;
                ByteSlice arg2 = args[2].Eval(out arg2type);
                if (arg2type.ID != DbTypeID.INT)
                {
                    args.Expected(FunctionName, 0, "input INT, got " + arg2type.Name.ToUpper());
                }
                if (!Types.IsNullValue(arg2))
                {
                    startIndex = tools.GetInt(arg2);
                }
            }
            
            mstring sentence = tools.GetString(arg0);
            mstring word = tools.GetString(arg1);
            int index = -1;
            if (startIndex < sentence.Length)
            {
                if (startIndex > 0)
                {
                    sentence = sentence.SubstringM(startIndex);
                }
                index = sentence.IndexOf(word);
                if (index > -1)
                {
                    index += startIndex;
                }
            }
            return tools.AllocValue(index);
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:60，代碼來源:DbFunctions_INSTR.cs

示例2: ADD_MONTHS

        public static DbValue ADD_MONTHS(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "ADD_MONTHS";

            args.EnsureCount(FunctionName, 2);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.DATETIME)
            {
                args.Expected(FunctionName, 0, "input DATETIME, got " + arg0type.Name.ToUpper());
            }
            DbType arg1type;
            ByteSlice arg1 = args[1].Eval(out arg1type);
            if (Types.IsNullValue(arg1))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg1type.ID != DbTypeID.INT)
            {
                args.Expected(FunctionName, 0, "input INT, got " + arg1type.Name.ToUpper());
            }

            DateTime dt = tools.GetDateTime(arg0);
            int months = tools.GetInt(arg1);
            dt = dt.AddMonths(months);            
            return tools.AllocValue(dt);
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:32，代碼來源:DbFunctions_ADD_MONTHS.cs

示例3: _BITWISE

        private static DbValue _BITWISE(string aggregatorName, DbFunctionTools tools, DbAggregatorArguments args, int whatop)
        {
            if (args.Length == 0)
            {
                return tools.AllocNullValue();
            }

            DbType arg0type = DbType.PrepareNull();

            for (int iarg = 0; iarg < args.Length; iarg++)
            {
                args[iarg].EnsureCount(aggregatorName, 1);
                ByteSlice arg0 = args[iarg][0].Eval(out arg0type);
                if (Types.IsNullValue(arg0))
                {
                    return tools.AllocNullValue();
                }

                if (bitopbuf == null || bitopbuf.Length != arg0type.Size)
                {
                    bitopbuf = new byte[arg0type.Size];                   
                }

                if (iarg == 0)
                {
                    for (int ib = 0; ib < arg0.Length; ib++)
                    {
                        bitopbuf[ib] = arg0[ib];
                    }
                    continue;
                }

                for (int ib = 1; ib < arg0.Length; ib++)
                {
                    switch (whatop)
                    {
                        case 1:
                            bitopbuf[ib] = (byte)(bitopbuf[ib] & arg0[ib]);
                            break;
                        case 2:
                            bitopbuf[ib] = (byte)(bitopbuf[ib] | arg0[ib]);
                            break;
                        default:
                            bitopbuf[ib] = (byte)(bitopbuf[ib] ^ arg0[ib]);
                            break;
                    }
                }
            }
            ByteSlice bs = ByteSlice.Prepare(bitopbuf);
            return tools.AllocValue(bs, arg0type);
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:51，代碼來源:DbAggregators_BIT_AND.cs

示例4: MONTHS_BETWEEN

        public static DbValue MONTHS_BETWEEN(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "MONTHS_BETWEEN";

            args.EnsureCount(FunctionName, 2);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.DATETIME)
            {
                args.Expected(FunctionName, 0, "input DATETIME, got " + arg0type.Name.ToUpper());
            }
            DbType arg1type;
            ByteSlice arg1 = args[1].Eval(out arg1type);
            if (Types.IsNullValue(arg1))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg1type.ID != DbTypeID.DATETIME)
            {
                args.Expected(FunctionName, 0, "input DATETIME, got " + arg1type.Name.ToUpper());
            }

            DateTime dt0 = tools.GetDateTime(arg0);
            DateTime dt1 = tools.GetDateTime(arg1);
            int daysInMonth0 = DateTime.DaysInMonth(dt0.Year, dt0.Month);
            int daysInMonth1 = DateTime.DaysInMonth(dt1.Year, dt1.Month);
            double btw = 0;

            if (dt0.Year == dt1.Year && dt0.Month == dt1.Month) //same month and same year
            {
                btw = (double)(dt0.Day - dt1.Day) / (double)daysInMonth0;
            }
            else if (dt0.Day == daysInMonth0 && dt1.Day == daysInMonth1) //both fall on the last day of their months
            {
                btw = 12 * (dt0.Year - dt1.Year) + dt0.Month - dt1.Month;
            }
            else
            {
                TimeSpan sp = dt0 - dt1;
                btw = sp.TotalDays / 31d;
            }
            
            return tools.AllocValue(btw);
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:49，代碼來源:DbFunctions_MONTHS_BETWEEN.cs

示例5: SPACE

        public static DbValue SPACE(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "SPACE";

            args.EnsureCount(FunctionName, 1);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.INT)
            {
                args.Expected(FunctionName, 0, "input INT, got " + arg0type.Name.ToUpper());
                return null;
            }

            int len = tools.GetInt(arg0);
            if (len < 1)
            {
                return tools.AllocValue(mstring.Prepare(""));
            }
            else
            {
                mstring s = mstring.Prepare();

                for (int i = 0; i < len; i++)
                {
                    s = s.AppendM(" ");
                }

                return tools.AllocValue(s);
            }            
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:35，代碼來源:DbFunctions_SPACE.cs

示例6: ROUND

        public static DbValue ROUND(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "ROUND";

            args.EnsureCount(FunctionName, 2);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.DOUBLE)
            {
                args.Expected(FunctionName, 0, "input DOUBLE, got " + arg0type.Name.ToUpper());
            }

            DbType arg1type;
            ByteSlice arg1 = args[1].Eval(out arg1type);
            if (arg1type.ID != DbTypeID.INT)
            {
                args.Expected(FunctionName, 1, "digits INT, got " + arg1type.Name.ToUpper());
            }

            int digits = tools.GetInt(arg1);
            double x = tools.GetDouble(arg0);
            x = Math.Round(x, digits);
            return tools.AllocValue(x);
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:29，代碼來源:DbFunctions_ROUND.cs

示例7: REVERSE

        public static DbValue REVERSE(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "REVERSE";

            args.EnsureCount(FunctionName, 1);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg0type.Name.ToUpper());
            }

            mstring x = tools.GetString(arg0);

            mstring r = mstring.Prepare();

            for (int i = x.Length-1; i >= 0; i--)
            {
                r = r.AppendM(x.SubstringM(i, 1));
            }

            return tools.AllocValue(r);
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:28，代碼來源:DbFunctions_REVERSE.cs

示例8: SUBSTRING

        public static DbValue SUBSTRING(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "SUBSTRING";

            args.EnsureCount(FunctionName, 3);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg0type.Name.ToUpper());
                return null;
            }

            DbType arg1type;
            ByteSlice arg1 = args[1].Eval(out arg1type);
            if (arg1type.ID != DbTypeID.INT)
            {
                args.Expected(FunctionName, 1, "count INT, got " + arg1type.Name.ToUpper());
                return null;
            }

            DbType arg2type;
            ByteSlice arg2 = args[2].Eval(out arg2type);
            if (arg2type.ID != DbTypeID.INT)
            {
                args.Expected(FunctionName, 1, "count INT, got " + arg2type.Name.ToUpper());
                return null;
            }

            mstring x = tools.GetString(arg0);
            int startIndex = tools.GetInt(arg1);
            if (startIndex < 0)
            {
                startIndex = 0;
            }
            int len = tools.GetInt(arg2);
            if (len < 0)
            {
                throw new ArgumentException(FunctionName + " length cannot be negative");
            }

            if (startIndex + len > x.Length)
            {
                return tools.AllocValue(mstring.Prepare());
            }
            else
            {
                mstring sub = x.SubstringM(startIndex, len);
                return tools.AllocValue(sub);
            }
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:56，代碼來源:DbFunctions_SUBSTRING.cs

示例9: REPLACE

        public static DbValue REPLACE(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "REPLACE";

            args.EnsureCount(FunctionName, 3);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg0type.Name.ToUpper());
            }
            DbType arg1type;
            ByteSlice arg1 = args[1].Eval(out arg1type);
            if (Types.IsNullValue(arg1))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg1type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg1type.Name.ToUpper());
            }
            DbType arg2type;
            ByteSlice arg2 = args[2].Eval(out arg2type);
            if (Types.IsNullValue(arg2))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg2type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg2type.Name.ToUpper());
            }

            mstring sentence = tools.GetString(arg0);
            mstring word = tools.GetString(arg1);
            mstring replacement = tools.GetString(arg2);
            sentence = sentence.ReplaceM(ref word, ref replacement);
            return tools.AllocValue(sentence);
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:43，代碼來源:DbFunctions_REPLACE.cs

示例10: FIRST

        public static DbValue FIRST(DbFunctionTools tools, DbAggregatorArguments args)
        {
            string AggregatorName = "FIRST";

            if (args.Length > 0)
            {
                args[0].EnsureCount(AggregatorName, 1);
                return args[0][0];
            }
            else
            {
                return tools.AllocNullValue();
            }
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:14，代碼來源:DbAggregators_FIRST.cs

示例11: FORMAT

        public static DbValue FORMAT(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "FORMAT";

            args.EnsureCount(FunctionName, 2);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            DbType arg1type;
            ByteSlice arg1 = args[1].Eval(out arg1type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg0type.Name.ToUpper());
            }
            if (Types.IsNullValue(arg1))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }
            if (arg1type.ID != DbTypeID.DATETIME)
            {
                args.Expected(FunctionName, 0, "input DATETIME, got " + arg1type.Name.ToUpper());
            }

            string formatstr = tools.GetString(arg0).ToString();            
            DateTime dt = tools.GetDateTime(arg1);

            mstring result = mstring.Prepare(dt.ToString(formatstr));
            while (result.Length < 80)
            {
                result.MAppend('\0');
            }
            return tools.AllocValue(result);
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:37，代碼來源:DbFunctions_FORMAT.cs

示例12: LAST

        public static DbValue LAST(DbFunctionTools tools, DbAggregatorArguments args)
        {
            string AggregatorName = "LAST";

            if (args.Length > 0)
            {
                int lastindex = args.Length - 1;
                args[lastindex].EnsureCount(AggregatorName, 1);
                return args[lastindex][0];
            }
            else
            {
                return tools.AllocNullValue();
            }
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:15，代碼來源:DbAggregators_LAST.cs

示例13: MAX

        public static DbValue MAX(DbFunctionTools tools, DbAggregatorArguments args)
        {
            string AggregatorName = "MAX";

            DbValue highest = null;
            DbValue nullest = null;
            DbFunctionArguments compareargs = new DbFunctionArguments(new DbValue[2]);
            ImmediateValue argval = null;
            for (int iarg = 0; iarg < args.Length; iarg++)
            {
                args[iarg].EnsureCount(AggregatorName, 1);
                DbType arg0type;
                ByteSlice arg0 = args[iarg][0].Eval(out arg0type);
                if (Types.IsNullValue(arg0))
                {
                    if (null == nullest)
                    {
                        nullest = tools.AllocValue(arg0, arg0type);
                    }
                }
                else
                {
                    if (null == argval)
                    {
                        argval = tools.AllocValue(arg0type.ID);
                    }
                    argval.SetValue(arg0);
                    compareargs[0] = argval;
                    compareargs[1] = highest;
                    if (null == highest || tools.GetInt(DbFunctions.COMPARE(tools, compareargs)) > 0)
                    {
                        highest = argval; // Keep this one.
                        argval = null; // New one next time.
                    }
                }
            }
            if (null == highest)
            {
                if (null == nullest)
                {
                    return tools.AllocNullValue();
                }
                return nullest;
            }
            return highest;

        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:47，代碼來源:DbAggregators_MAX.cs

示例14: CHOOSERND

        public static DbValue CHOOSERND(DbFunctionTools tools, DbAggregatorArguments args)
        {
            string AggregatorName = "CHOOSERND";

            if (args.Length == 0)
            {
                return tools.AllocNullValue();
            }
            if (anyRnd == -1)
            {
                Random rnd = new Random(System.DateTime.Now.Millisecond / 2 + System.Diagnostics.Process.GetCurrentProcess().Id / 2);
                anyRnd = rnd.Next();
            }
            int index = anyRnd % args.Length;
            args[index].EnsureCount(AggregatorName, 1);
            return args[index][0];
        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:17，代碼來源:DbAggregators_CHOOSERND.cs

示例15: ABS

        public static DbValue ABS(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "ABS";

            args.EnsureCount(FunctionName, 1);

            DbType arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            if (Types.IsNullValue(arg0))
            {
                return tools.AllocNullValue(); // Give a null, take a null.
            }

            switch (arg0type.ID)
            {
                case DbTypeID.INT:
                    {
                        int x = tools.GetInt(arg0);
                        x = Math.Abs(x);
                        return tools.AllocValue(x);
                    }
                    break;

                case DbTypeID.LONG:
                    {
                        long x = tools.GetLong(arg0);
                        x = Math.Abs(x);
                        return tools.AllocValue(x);
                    }
                    break;

                case DbTypeID.DOUBLE:
                    {
                        double x = tools.GetDouble(arg0);
                        x = Math.Abs(x);
                        return tools.AllocValue(x);
                    }
                    break;

                default:
                    args.Expected(FunctionName, 0, "input INT, LONG or DOUBLE, got " + arg0type.Name.ToUpper());
                    return null; // Doesn't reach here.
            }

        }

開發者ID:erisonliang，項目名稱:qizmt，代碼行數:45，代碼來源:DbFunctions_ABS.cs

注：本文中的RDBMS_DBCORE.DbFunctionTools.AllocNullValue方法示例由純淨天空整理自Github/MSDocs等開源代碼及文檔管理平台，相關代碼片段篩選自各路編程大神貢獻的開源項目，源碼版權歸原作者所有，傳播和使用請參考對應項目的License；未經允許，請勿轉載。