RE: [sqlite] vxworks
We have been successfully been using sqlite in several flavors of Vxworks. I have ported it over to PPC604, X86, and PC_SIM. We had to do some kludging to get it to work concurrently and coherently. 1. We modified os.c and added a semaphore for the singleton file. 2. We wrote our own arbitration handle between processes so, if one data base is common across tasks, it needs arbitration and separate handles to it. 3. If you plan on using in memory databases we switched them over to a ram drive and it the rest of the arbitration works just fine. We have used this port successfully across several projects. Please let me know if this helps. Tezozomoc. Original Message Follows From: Martin Pfeifle <[EMAIL PROTECTED]> Reply-To: sqlite-users@sqlite.org To: sqlite-users@sqlite.org Subject: [sqlite] vxworks Date: Wed, 12 Oct 2005 15:01:32 +0200 (CEST) Hi, I am in deep trouble. I would like to use sqlite on vxworks. There are no fysnc, fcntl calls available which are used in os_unix.c. Can anybody help me? PLEASE! ___ Gesendet von Yahoo! Mail - Jetzt mit 1GB Speicher kostenlos - Hier anmelden: http://mail.yahoo.de
Re: [sqlite] preventing text to integer conversion of bind variables in perl
Please verify that they have implemented a 'natural sort' vs. a 'lexical sort' Tezo. Original Message Follows From: Darren Duncan <[EMAIL PROTECTED]> Reply-To: sqlite-users@sqlite.org To: sqlite-users@sqlite.org Subject: Re: [sqlite] preventing text to integer conversion of bind variables in perl Date: Wed, 15 Jun 2005 18:12:26 -0700 At 12:55 AM +0000 6/16/05, Mr. Tezozomoc wrote: sqlite is typeless I have addressed this issue in the following HOWTO: http://www.mail-archive.com/sqlite-users@sqlite.org/msg03205.html Please refer to it. Tezozomoc. I think not. From your own HOWTO: Assumption... this is based on SQLITE 2.8.6... forgive the aging.. I believe that this is out of date and not applicable. The SQLite 3.x line is not typeless and has distinct numerical and text and binary data types. Therefore it should be able to take columns declared as numbers and sort them as such. -- Darren Duncan
Re: [sqlite] preventing text to integer conversion of bind variables in perl
sqlite is typeless
I have addressed this issue in the following HOWTO:
http://www.mail-archive.com/sqlite-users@sqlite.org/msg03205.html
Please refer to it.
Tezozomoc.
Original Message Follows
From: Darren Duncan <[EMAIL PROTECTED]>
Reply-To: sqlite-users@sqlite.org
To: sqlite-users@sqlite.org, Matt Sergeant <[EMAIL PROTECTED]>
Subject: Re: [sqlite] preventing text to integer conversion of bind
variables in perl
Date: Wed, 15 Jun 2005 17:45:44 -0700
At 11:39 AM -0400 6/15/05, Matt Sergeant wrote:
I added it because of another bug report that was incorrectly sorting
integer columns based on text sort order. For example if you inserted:
("k1", 8);
("k2", 9);
("k3", 10);
("k4", 11);
and then asked for: SELECT * FROM t ORDER BY Column2
you get back:
k3, 10
k4, 11
k1, 8
k2, 9
Which seems obviously incorrect.
In answer to your question though, yes you can remove that bit of code, as
long as you're aware of the above side effect.
Well, if Column2 is explicitly defined as an integer, then it should always
sort as an integer, and making that work is the responsibility of SQLite
itself.
I see that preserving the input data in all situations where the declared
column type can handle it is of the utmost importance, and DBD::SQLite
should do this.
So I vote to remove any de-stringification code you have in DBD::SQLite.
To be honest I'm not entirely sure what the correct fix is - maybe ignore
the above bug and tell the requestor he has to: SELECT * FROM t ORDER BY
int(Column2)
Yes, go ahead and do that. Alternately, tell the person to use SQLite in
strict mode so that it only ever stores ints in int columns. Like most
databases do.
Matt, I would also appreciate it if a new DBD::SQLite was released asap that
embeds and is known to work well with the 3.2 series, specifically 3.2.2.
Thank you in advance.
-- Darren Duncan
[sqlite] Assert with sql 2.6.8....
I am getting this assert when I call my sqlite from a c++ program... i have if def for c extern all of the files and everything compiles... but I get this error... main.c Assert (iDb>=0 && iDbnDb)failed in file ../../sqlite/src/build.c at line 2154 Anybody have any ideas... what my problem is. Tezozomoc.
RE: [sqlite] Any successful VxWorks ports out there?
Does this mean that the in memory database can be accessed by more than one task without giving schema corruption? This is the problem I was having the 2.8.x... version... Tezo Original Message Follows From: "D. Richard Hipp" <[EMAIL PROTECTED]> Reply-To: sqlite-users@sqlite.org To: sqlite-users@sqlite.org Subject: RE: [sqlite] Any successful VxWorks ports out there? Date: Wed, 02 Mar 2005 15:13:18 -0500 On Wed, 2005-03-02 at 19:35 +0000, Mr. Tezozomoc wrote: > I have successfully port 2.8.15 to vxworks > The in memory database is very problematic > Note that the in-memory database for version 3.x is completely new and uses a different approach than the in-memory database in version 2.8.x. So whatever the problems were that Mr. Tezozomoc had, they may well be gone now. -- D. Richard Hipp <[EMAIL PROTECTED]>
RE: [sqlite] Any successful VxWorks ports out there?
I have successfully port 2.8.15 to vxworks I have ported over to PPC604 and PENTIUM The main catch here is the ... that there is no file locking in vxworks This is the major problem. You have to write your own wrapper to prevent multiple tasks accessing the database... I wrote my own busy handler that pends on the database when it is busy and throws 1 task delay... On a pentium 200 MHZ I was able to achieve extremely fast responses using pre-compile queries. Another big gotcha... is that sqlite uses a lot of Mallocs... this will cause problems in VXworks... eventually... the memory becomes fragmented and it cause problems... so I switched to using memory pools... this reduced this problem... The pure 'c' version is very easy to compile. The in memory database is very problematic If you want to do an in memory database and are going to access it with more than one task, i recommend the following I implemented a ramdrive and trick sqlite into thinking it is running from a real drive... This will give the best of both worlds without lossing to much performance Let me know if you need any more info... Tezo. Original Message Follows From: "Andrew Lukasik" <[EMAIL PROTECTED]> Reply-To: sqlite-users@sqlite.org To: "'sqlite-users@sqlite.org'" Subject: [sqlite] Any successful VxWorks ports out there? Date: Wed, 2 Mar 2005 14:19:49 -0500 I'm currently using SQLite on Linux but I'm considering a port to VxWorks. Has anyone done this successfully? Care to comment? I took a look thru the archives, there wasn't a whole lot there. I'd be interested in knowing: a) how difficult/lengthy was the port b) pitfalls/got-chas c) performance - does sqlite perform as well here as other known OS's? d) eperience w/ in-memory databases on VxWorks? e) other db alternatives you rejected, and why. Thanks, /Andrew Andrew J. Lukasik Nortel Networks Phone:(978)-288-6861, ESN 248-6861 Email: [EMAIL PROTECTED]
RE: [sqlite] Best way to check for existence of a table?
Try something like .
dba_int_t dba_check_table_exist (dba_void_t *hndArg, dba_char_t *table)
{
/**/
/* Local Variables:
*/
/**/
dba_handle_t*pHnd = (dba_handle_t *)hndArg;
dba_status_tstatus = DBA_TABLE_NOT_EXIST;
dba_result_tres, *pResult=&res;
dba_char_t statement[200];
dba_char_t *pErrMsg = NULL;
dba_int_t rc = 0;
dba_int_t time_delays = 0;
/**/
/* Function Body:
*/
/**/
if ( (pHnd != NULL) && (pHnd->magic == DBA_HANDLE_MAGIC) )
{
/* init sqlite database */
if( ( pHnd->db != NULL ) && (statement != NULL) )
{
pResult->result_table = NULL;
pResult->numrows = 0;
pResult->numcols = 0;
sprintf(statement,
"SELECT name FROM sqlite_master WHERE type='table' and
name='%s'",
table);
do {
rc = sqlite_get_table(pHnd->db,
statement,
&pResult->result_table,
&pResult->numrows,
&pResult->numcols,
&pErrMsg);
if ((rc==SQLITE_BUSY)||(rc==SQLITE_LOCKED)){
#ifdef _VXWORKS
taskDelay(DBA_DB_WAIT_TIME);
#endif
if (time_delays > DBA_DB_WAIT_MAX){
/* it looks like there might be a problem with db */
/* its time to bail */
rc = SQLITE_ERROR;
break;
}
time_delays++;
if(dba_debug){
#ifdef _VXWORKS
logMsg("%s: # of Delays
%d\n",__FUNCTION__,time_delays,0,0,0,0);
#endif
}
}
} while((rc==SQLITE_BUSY)||(rc==SQLITE_LOCKED));
if (pErrMsg != NULL)
{
if(dba_debug)
printf("dba_exec: %s\n", pErrMsg);
dba_free(pErrMsg);
}
if ( rc == SQLITE_OK )
{
if(pResult->numrows == 1){
status = DBA_TABLE_EXIST;
}
else {
status = DBA_TABLE_NOT_EXIST;
}
if(dba_debug){
printf("dba_exec: Exists =%s\n", table);
}
}
/* free if any rows */
dba_free_table (pResult);
} /* if( ( pHnd->db != NULL ) && (statement != NULL) ) */
} /* ( (pHnd != NULL) && (pHnd->magic == DBA_HANDLE_MAGIC) ) */
if (status == DBA_TABLE_EXIST){
return (status);
}
else {
return (rc);
}
/* return (status);*/
} /* end of dba_check_table_exist */
Original Message Follows
From: [EMAIL PROTECTED]
Reply-To: sqlite-users@sqlite.org
To: sqlite-users@sqlite.org
Subject: RE: [sqlite] Best way to check for existence of a table?
Date: Mon, 14 Feb 2005 15:35:53 -0500
did you try:
SELECT NULL FROM sqlite_master WHERE tbl_name = 'table';
Regards,
[EMAIL PROTECTED]
NCCI
Boca Raton, Florida
561.893.2415
greetings / avec mes meilleures salutations / Cordialmente
mit freundlichen Grüßen / Med vänlig hälsning
"Richard Boyd"
<[EMAIL PROTECTED]To:
.com>cc:
Subject: RE: [sqlite] Best
way to check for existence of a table?
02/14/2005 03:05
PM
Please respond to
sqlite-users
Thanks for the prompt reply...
I tried what you suggested and I always get the error message:
"SQL error: no such column: table32"
Whether the table exists or not, I always get returned value of 1 from
sqlite3_exec().
The exact command that I use is:
SELECT count(*) FROM sqlite_master WHERE name=table32 AND type='table';
I also tried single quotes around the table32 name:
SELECT count(*) FROM sqlite_master WHERE name='table32' AND type='table';
And get no errors whether the table exists or not
When I try the other method suggested ("SELECT NULL FROM sqlite_master
WHERE
tbl_name = 'your-table';") I don’t get any error messages whether the
table
exists or not. The return value is always 0.
I'm obviously missing where the error is being flagged, have you any more
pointers?
Sorry if I'm being dense here but I'm new to SQL databases.
Thanks again,
Richard.
-Original Message-
[sqlite] HOWTO: Overcome the single threadness of the in-memory database...
There is a systemic problem with sqlite and multi-thread access to the in memory database. 1. Create a RAM Drive. [OS specific, see your development software.] 2. Point database to the RAM Drive. You should not suffer too much speed degredation from the RAM Drive. 3. This will give you all the locking capabilities of the file system and over come single threadness. Tezozomoc.
Re: [sqlite] HOWTO: Adding Natural Sort To Sqlite Database...
The current implementation of SQlite resorts strcmp which does a lexicographical compare... for example consider the following items... Field NAME GPI_1 GPI_2 GPI_20 GPI_10 if I run the following sql statement SELECT * FROM list ORDER BY NAME I will get the following data sorted: GPI_1 GPI_10 GPI_2 GPI_20 Which is not really what I meant. If you patch sqlite for natural sort the same code will yield the following: GPI_1 GPI_2 GPI_10 GPI_20 This is what's called a natural sort.. its what we are used to as non computers... Tezozomoc. - Original Message - From: "gohaku" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: "tezozomoc" <[EMAIL PROTECTED]> Sent: Saturday, July 31, 2004 6:20 AM Subject: Re: [sqlite] HOWTO: Adding Natural Sort To Sqlite Database... > > On Jul 30, 2004, at 1:49 PM, tezozomoc wrote: > > > > > HOWTO: Adding Natural Sort To Sqlite Database... > > > > Assumption... this is based on SQLITE 2.8.6... forgive the aging.. > > > > > > I will make this very short and sweet... > > > > 1. Get the following two files: > > > > a.. strnatcmp.c, strnatcmp.h - the algorithm itself from > > a.. > > http://sourcefrog.net/projects/natsort/ > > > > add to your sqlite build project, I am using VxWorks, so the way that > > I did it will probably will not make sense... > > > > 2. Open util.c > > > > 3. Replace the following: > > > > This sounds great. can you give an SQL Statement example and explain > what was wrong with sqliteSortCompare? > > Thanks. > >
