A very interesting discussion thread! Thanks to everyone who posted for
adding to my knowledge.
Bob Cochran
[EMAIL PROTECTED] wrote:
Matt Sergeant <[EMAIL PROTECTED]> wrote:
Perl has no concept of blobs. A scalar variable can be one of:
IV (integer)
UV (unsigned integer)
NV (double)
PV (string)
so a blob is just a string - but perl carries a length around with it
so you can have binary data in there.
SQLite does has a separate BLOB type. But for TEXT types, SQLite
still works like Perl and carries around a length so that the string
can have embedded '\000' characters. I just added a test to the
test suite to verify that this works.
Suppose you do this:
sqlite3_bind_text(pVm, 1, "abc\000xyz\000pq", 10, SQLITE_STATIC);
If this is part of an INSERT, say, then you will insert a 10-character
string that happens to contain a couple of extra \000 characters.
The statement:
SELECT length(x) FROM table;
will return 3 because the length() function is counting UTF-8 characters,
not bytes, and it will stop at the first '\000'. But if you say this:
SELECT length(cast(x AS blob)) FROM table;
you will get 10, because length() returns the number of bytes in a blob.
Similarly, if you say:
SELECT quote(x) FROM table;
you will get 'abc' as a reply. But if you say:
SELECT quote(cast(x AS blob)) FROM table;
then you will get X'6162630078797A007071' as the result. So you see,
all 10 bytes of the original string are still there.
So as far as I can tell, both SQLite and Perl are doing exactly what
they ought to be.
--
D. Richard Hipp <[EMAIL PROTECTED]>
