public static DbValue CHARINDEX(DbFunctionTools tools, DbFunctionArguments args)
{
string FunctionName = "CHARINDEX";
args.EnsureMinCount(FunctionName, 2);
int index = -1;
DbType arg0type;
ByteSlice arg0 = args[0].Eval(out arg0type);
DbType arg1type;
ByteSlice arg1 = args[1].Eval(out arg1type);
if (Types.IsNullValue(arg0) || Types.IsNullValue(arg1))
{
return(tools.AllocValue(index));
}
if (arg0type.ID != DbTypeID.CHARS)
{
args.Expected(FunctionName, 0, "input CHAR(n), got " + arg0type.Name.ToUpper());
return(null);
}
if (arg1type.ID != DbTypeID.CHARS)
{
args.Expected(FunctionName, 0, "input CHAR(n), got " + arg1type.Name.ToUpper());
return(null);
}
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());
return(null);
}
startIndex = tools.GetInt(arg2);
if (startIndex < 0)
{
startIndex = 0;
}
}
mstring word = tools.GetString(arg0);
mstring sentence = tools.GetString(arg1);
if (startIndex > sentence.Length - 1)
{
index = -1;
}
else if (startIndex == 0)
{
index = sentence.IndexOf(word);
}
else
{
mstring partsentence = sentence.SubstringM(startIndex);
int ix = partsentence.IndexOf(word);
if (ix == -1)
{
index = -1;
}
else
{
index = startIndex + ix;
}
}
return(tools.AllocValue(index));
}
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));
}
