public static DbValue MUL(DbFunctionTools tools, DbFunctionArguments args)
{
string FunctionName = "MUL";
args.EnsureCount(FunctionName, 2);
DbType arg0type;
ByteSlice arg0 = args[0].Eval(out arg0type);
if (Types.IsNullValue(arg0))
{
return(tools.AllocValue(arg0, arg0type)); // Give a null, take a null.
}
DbType arg1type;
ByteSlice arg1 = args[1].Eval(out arg1type);
if (Types.IsNullValue(arg1))
{
return(tools.AllocValue(arg1, arg1type)); // Give a null, take a null.
}
switch (arg0type.ID)
{
case DbTypeID.INT:
{
int x = tools.GetInt(arg0);
switch (arg1type.ID)
{
case DbTypeID.INT:
{
int y = tools.GetInt(arg1);
return(tools.AllocValue(x * y));
}
break;
case DbTypeID.LONG:
{
long y = tools.GetLong(arg1);
return(tools.AllocValue(x * y));
}
break;
case DbTypeID.DOUBLE:
{
double y = tools.GetDouble(arg1);
return(tools.AllocValue(x * y));
}
break;
default:
args.Expected(FunctionName, 1, "input INT, LONG or DOUBLE, got " + arg1type.Name.ToUpper());
return(null); // Doesn't reach here.
}
}
break;
case DbTypeID.LONG:
{
long x = tools.GetLong(arg0);
switch (arg1type.ID)
{
case DbTypeID.INT:
{
int y = tools.GetInt(arg1);
return(tools.AllocValue(x * y));
}
break;
case DbTypeID.LONG:
{
long y = tools.GetLong(arg1);
return(tools.AllocValue(x * y));
}
break;
case DbTypeID.DOUBLE:
{
double y = tools.GetDouble(arg1);
return(tools.AllocValue(x * y));
}
break;
default:
args.Expected(FunctionName, 1, "input INT, LONG or DOUBLE, got " + arg1type.Name.ToUpper());
return(null); // Doesn't reach here.
}
}
break;
case DbTypeID.DOUBLE:
{
double x = tools.GetDouble(arg0);
switch (arg1type.ID)
{
case DbTypeID.INT:
{
int y = tools.GetInt(arg1);
return(tools.AllocValue(x * y));
}
break;
case DbTypeID.LONG:
{
long y = tools.GetLong(arg1);
return(tools.AllocValue(x * y));
}
break;
case DbTypeID.DOUBLE:
{
double y = tools.GetDouble(arg1);
return(tools.AllocValue(x * y));
}
break;
default:
args.Expected(FunctionName, 1, "input INT, LONG or DOUBLE, got " + arg1type.Name.ToUpper());
return(null); // Doesn't reach here.
}
}
break;
default:
args.Expected(FunctionName, 0, "input INT, LONG or DOUBLE, got " + arg0type.Name.ToUpper());
return(null); // Doesn't reach here.
}
}
DbValue ExpressionToDbValue(string value, Types.ExpressionType etype)
{
switch(etype)
{
case Types.ExpressionType.FUNCTION:
{
int ilp = value.IndexOf('(');
#if DEBUG
if (-1 == ilp)
{
throw new Exception("DEBUG: ExpressionToDbValue: function expects (");
}
if (!value.EndsWith(")"))
{
throw new Exception("DEBUG: ExpressionToDbValue: function expects )");
}
#endif
string fname = value.Substring(0, ilp);
string sargs = value.Substring(ilp + 1, value.Length - ilp - 1 - 1);
List<DbValue> args = new List<DbValue>();
StringPartReader argsparser = new StringPartReader(sargs);
if (argsparser.PeekPart().Length != 0)
{
for (; ; )
{
if (0 == string.Compare("AS", argsparser.PeekPart(), true))
{
argsparser.NextPart(); // Eat "AS".
{
StringBuilder sbas = new StringBuilder();
int asparens = 0;
for (; ; )
{
string s = argsparser.PeekPart();
if (0 == s.Length || "," == s)
{
break;
}
else if ("(" == s)
{
asparens++;
sbas.Append(argsparser.NextPart());
}
else if (")" == s)
{
if (0 == asparens)
{
break;
}
asparens--;
sbas.Append(argsparser.NextPart());
}
else
{
sbas.Append(argsparser.NextPart());
}
}
if (0 == sbas.Length)
{
throw new Exception("Expected type after AS");
}
args.Add(ExpressionToDbValue("'AS " + sbas.Replace("'", "''") + "'",
Types.ExpressionType.AS));
}
}
else
{
string argvalue;
Types.ExpressionType argetype;
argvalue = Types.ReadNextBasicExpression(argsparser, out argetype);
args.Add(ExpressionToDbValue(argvalue, argetype));
}
{
string s = argsparser.PeekPart();
if (s != ",")
{
if (0 == string.Compare("AS", s, true))
{
continue;
}
if (s.Length != 0)
{
throw new Exception("Unexpected in function arguments: " + argsparser.RemainingString);
}
break;
}
}
argsparser.NextPart(); // Eat the ','.
}
}
return new FuncEvalValue(this, fname, args);
}
break;
case Types.ExpressionType.NAME:
{
int FieldIndex = _IndexOfRowColType_ensure(value);
return new ColValue(this, ColumnTypes[FieldIndex]);
}
break;
case Types.ExpressionType.NUMBER:
case Types.ExpressionType.STRING:
case Types.ExpressionType.AS:
case Types.ExpressionType.NULL:
{
DbTypeID id;
ByteSlice bs = Types.LiteralToValue(value, out id);
return new ImmediateValue(this, bs, DbType.Prepare(bs.Length, id));
}
break;
default:
throw new Exception("Unexpected value: " + value);
}
}
public static DbValue IIF(DbFunctionTools tools, DbFunctionArguments args)
{
string FunctionName = "IIF";
args.EnsureCount(FunctionName, 3);
DbType arg0type;
ByteSlice arg0 = args[0].Eval(out arg0type);
DbType arg1type;
ByteSlice arg1 = args[1].Eval(out arg1type);
DbType arg2type;
ByteSlice arg2 = args[2].Eval(out arg2type);
bool truecond;
if (Types.IsNullValue(arg0))
{
truecond = false;
}
else if (DbTypeID.INT == arg0type.ID)
{
truecond = 0 != tools.GetInt(arg0);
}
else if (DbTypeID.LONG == arg0type.ID)
{
truecond = 0 != tools.GetLong(arg0);
}
else if (DbTypeID.DOUBLE == arg0type.ID)
{
truecond = 0 != tools.GetDouble(arg0);
}
else
{
bool allzero = true;
for (int i = 1; i < arg0.Length; i++)
{
if (arg0[i] != 0)
{
allzero = false;
break;
}
}
truecond = !allzero;
}
byte[] resultbuf = new byte[arg1.Length > arg2.Length ? arg1.Length : arg2.Length];
DbType resulttype;
if (truecond)
{
resulttype = DbType.Prepare(resultbuf.Length, arg1type.ID);
for (int i = 0; i < arg1.Length; i++)
{
resultbuf[i] = arg1[i];
}
}
else
{
resulttype = DbType.Prepare(resultbuf.Length, arg2type.ID);
for (int i = 0; i < arg2.Length; i++)
{
resultbuf[i] = arg2[i];
}
}
return(tools.AllocValue(ByteSlice.Prepare(resultbuf), resulttype));
}
