On 9/10/2012 1:22 PM,
kball...@kennethballard.com wrote:
Here's one that I wrote a while back:
void sqlite3_instr(sqlite3_context* pContext, int argc, sqlite3_value** argv)
{
const char *str1 = (const char *) sqlite3_value_text(argv[0]);
const char *str2 = (const char *) sqlite3_value_text(argv[1]);
char *p = strstr(str1, str2);
int nResult = 0;
if(p != NULL)
{
nResult = p - str1 + 1;
}
sqlite3_result_int(pContext, nResult);
}
This returns an offset in bytes, not in characters. I would expect a
reasonable instr() implementation to satisfy this identity:
substr(X, instr(X, Y), length(Y)) == Y
for all strings X and Y, or at least for those where Y does in fact
appear in X. I don't think yours would satisfy this condition for
strings containing non-ASCII characters.
One would probably want to study the implementation of substr and length
before implementing instr, to make sure the three play well together.
--
Igor Tandetnik
_______________________________________________
sqlite-users mailing list
sqlite-users@sqlite.org
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
