Re: [sqlite] Latin-1 characters cannot be supported for Unicode
On 6/7/2016 9:49 PM, Wang, Wei wrote: Thanks for your reply! But I found the Latin-1 encoded characters are listed in the Unicode chart. http://unicode.org/charts/PDF/U0080.pdf All the characters available in Latin-1 codepage are indeed also available in Unicode. However, the same character is represented by a different sequence of bytes when encoded in an ANSI codepage, in UTF-8, and in UTF-16. For example, character Ç (aka U+00C7) is represented by a single byte C7 in ANSI Latin-1 encoding, by two bytes C3 87 in UTF-8, and by two bytes C7 00 in UTF-16LE. I suggest you read http://www.joelonsoftware.com/articles/Unicode.html . -- Igor Tandetnik ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Latin-1 characters cannot be supported for Unicode
Thanks for your reply! But I found the Latin-1 encoded characters are listed in the Unicode chart. http://unicode.org/charts/PDF/U0080.pdf Best Regards, Wang Wei -Original Message- From: sqlite-users-boun...@mailinglists.sqlite.org [mailto:sqlite-users-boun...@mailinglists.sqlite.org] On Behalf Of Igor Tandetnik Sent: Tuesday, June 07, 2016 10:20 PM To: sqlite-users@mailinglists.sqlite.org Subject: Re: [sqlite] Latin-1 characters cannot be supported for Unicode On 6/7/2016 3:43 AM, Wang, Wei wrote: > I met a problem that was maybe caused by the encoding of SQLite. I inserted a > item which including some Latin1 characters like Ç and à into a table. Then > I opened the database with SQLite Developer. After I setting the encoding to > ANSI, the display and the query result for that table were OK. > However after I setting the encoding to Unicode, these Latin1 characters > could not be displayed normally, and could not be queried out. Please see the > attached pictures for the details. A byte sequence containing Latin-1-encoded characters Ç or à is not in fact a valid byte sequence in any Unicode encoding - neither UTF-8 nor UTF-16 nor any other. If you want Unicode data in your database, then store Unicode data, and not ANSI, in your database. -- Igor Tandetnik ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] SQL / SQLite for Beginners
That was what I was trying to say - thanks for the superior spelling. Also - for wee Java folks, I cobbled together a CRUD generator for SQLite last night: https://sourceforge.net/projects/sqlmate Also on: https://github.com/soft9000/SQLMate Sharing is caring, -Rn On Tue, Jun 7, 2016 at 12:24 AM, James K. Lowden wrote: > On Thu, 26 May 2016 10:54:30 -0400 > r.a.n...@gmail.com wrote: > > > FWIW, since it's inception, S.Q.L has been pronounced allot like > > CICS. > > This may be more true than you know. It's not too hard to find > old-timers who pronounce it "kicks". > > --jkl > > ___ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] UPDATE statement without FROM clause
Hi, of course there is in general a difference between syntax complexity and performance but unfortunately not in this case. And the „just“ is very often the most difficult part. Regards, Hartwig > Am 2016-06-07 um 07:39 schrieb James K. Lowden : > > On Sat, 4 Jun 2016 18:18:36 +0200 > skywind mailing lists wrote: > >> At the moment I have to run something like: >> >> UPDATE A SET item1=(SELECT B.item FROM B WHERE B.ID=A.ID),... >> itemN=... WHERE EXISTS (SELECT 1 FROM B WHERE B.ID=A.ID); >> >> Using a FROM clause I just need one scan through B (at least in >> principle). Now, I need N+1 scans. > > Nonsense. SQL provides no instruction to the implementation on how to > organize or traverse the data. SQLite is free to scan B once, twice, > or not at all. > > Syntax has nothing to do with performance. A correlated subquery is an > expression of logic; it's not meant to be taken literally, and often > isn't. This particular form "just" needs to be recognized by the > optimizer. > > --jkl > ___ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Latin-1 characters cannot be supported for Unicode
As already stated, this is not a problem of SQLite. SQLite assumes all input to be correctly encoded in UTF (unicode), the precise flavor of which may be set (once, between creating a db file and the first insert) by a pragma. If you insert ISO (latin) encoded strings, SQLite will faithfully reproduce the exact sequence of bytes presented on insert. As long as you use the same encoding to display the results, everything seems tob e ok, even though the byte sequence stored is technically worng. If you insist on interpreting these using a different encoding and without explicitly converting, then you will experience problems with characters that encode differently. -Ursprüngliche Nachricht- Von: sqlite-users-boun...@mailinglists.sqlite.org [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im Auftrag von Wang, Wei Gesendet: Dienstag, 07. Juni 2016 09:43 An: sqlite-users@mailinglists.sqlite.org Betreff: [sqlite] Latin-1 characters cannot be supported for Unicode Hi, I met a problem that was maybe caused by the encoding of SQLite. I inserted a item which including some Latin1 characters like Ç and à into a table. Then I opened the database with SQLite Developer. After I setting the encoding to ANSI, the display and the query result for that table were OK. However after I setting the encoding to Unicode, these Latin1 characters could not be displayed normally, and could not be queried out. Please see the attached pictures for the details. Best Regards, Wang Wei ___ Gunter Hick Software Engineer Scientific Games International GmbH FN 157284 a, HG Wien Klitschgasse 2-4, A-1130 Vienna, Austria Tel: +43 1 80100 0 E-Mail: h...@scigames.at This communication (including any attachments) is intended for the use of the intended recipient(s) only and may contain information that is confidential, privileged or legally protected. Any unauthorized use or dissemination of this communication is strictly prohibited. If you have received this communication in error, please immediately notify the sender by return e-mail message and delete all copies of the original communication. Thank you for your cooperation. ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Latin-1 characters cannot be supported for Unicode
On 7 Jun 2016, at 8:43am, Wang, Wei wrote: > Then I opened the database with SQLite Developer. SQLite Developer is not supported by the team which wrote SQLite. It's just a program which uses SQLite. If it allows you to pick character encoding then it is not correctly showing you the contents of your database so you should not necessarily trust what you see. If you want to see what's really in your database please use the SQLite shell tool, which was written by the team which wrote SQLite and is understood to be 100% correct. Simon. ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Latin-1 characters cannot be supported for Unicode
On 6/7/2016 3:43 AM, Wang, Wei wrote: I met a problem that was maybe caused by the encoding of SQLite. I inserted a item which including some Latin1 characters like Ç and à into a table. Then I opened the database with SQLite Developer. After I setting the encoding to ANSI, the display and the query result for that table were OK. However after I setting the encoding to Unicode, these Latin1 characters could not be displayed normally, and could not be queried out. Please see the attached pictures for the details. A byte sequence containing Latin-1-encoded characters Ç or à is not in fact a valid byte sequence in any Unicode encoding - neither UTF-8 nor UTF-16 nor any other. If you want Unicode data in your database, then store Unicode data, and not ANSI, in your database. -- Igor Tandetnik ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] [BugReport]Data changes cannot actually flush to disk
Dear SQLite developers, Sqlite version: 3.8.8.3 Linux version: 3.10.31-ltsi Problem: When update database and power off immediately, it cannnot actually make changes to database file in the disk. Although the HAVE_FDATASYNC comile-time option is true. If manually called sync() after executing a SQL statement, it does flush the database file to disk. I think the OSTRACE log can be helpful, so I toke it. Could you help to analyse it and tell me why fdatasync() doesn't work? LOCK154 SHARED was NONE(NONE,0) pid=2289 (unix) LOCK154 SHARED ok (unix) READ15416 24 0 LOCK154 RESERVED was SHARED(SHARED,1) pid=2289 (unix) LOCK154 RESERVED ok (unix) OPENX 168 /var/user/aaa/bbb.db-journal 0400102 OPEN168 /var/user/aaa/bbb.db-journal WRITE 168 512 0 0 WRITE 168 4 512 0 WRITE 168 1024 516 0 WRITE 168 41540 0 LOCK154 EXCLUSIVE was RESERVED(RESERVED,1) pid=2289 (unix) LOCK154 EXCLUSIVE ok (unix) WRITE 168 41544 0 WRITE 168 10241548 0 WRITE 168 42572 0 READ168 03072 0 SYNC168 DIRSYNC /var/user/aaa/bbb.db-journal (have_fullfsync=0 fullsync=0) OPENDIR 169 /var/user/aaa WRITE 16812 0 0 SYNC168 READ154 4 24 0 WRITE 154 1024 0 0 WRITE 154 1024 20480 0 SYNC154 CLOSE -1 UNLOCK 154 1 was 4(4,1) pid=2289 (unix) UNLOCK 154 0 was 1(1,1) pid=2289 (unix) Cordially yours LiuXiang ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] Latin-1 characters cannot be supported for Unicode
Hi, I met a problem that was maybe caused by the encoding of SQLite. I inserted a item which including some Latin1 characters like Ç and à into a table. Then I opened the database with SQLite Developer. After I setting the encoding to ANSI, the display and the query result for that table were OK. However after I setting the encoding to Unicode, these Latin1 characters could not be displayed normally, and could not be queried out. Please see the attached pictures for the details. Best Regards, Wang Wei ___ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
