World: r3wp
[SQLite] C library embeddable DB .
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GiuseppeC 15-Oct-2008 [743x2] | It should be 0,5 KB per row. |
So the database will be around 250MB. Is SQL Lite disk based or could we instruct it to load the database in memory ? | |
Pekr 15-Oct-2008 [745] | IIRC it allows also in-memory tables, but not 100% sure ... |
Henrik 15-Oct-2008 [746] | The trouble for REBOL starts when you want to save the db to disk or load it into memory. You'll have to implement a clever algorithm to make it fast. |
Maarten 15-Oct-2008 [747x2] | I think you should try parse on a large file with /seek, just to test. Or load it in memory upfront, so you hav the cost once. |
I mean, 250Mb is not so much. Only 1000 times the rebol executable | |
Ashley 15-Oct-2008 [749] | RebDB is memory-based, or if your DB structure and access is simple enoiugh just use sorted blocks. You really only *need* a DB if you require a complex access API such as SQL. |
Robert 16-Oct-2008 [750] | SQLite can use in memory tables. If persistens is not an issue and you just need to query and not changes are necessary SQLite is a good catch. But if your queries are very simple lookup and don't change in structure load everything and write a simple accessor function. |
Ashley 17-Oct-2008 [751] | How would I add the following routine to sqlite.r: SQLITE_EXTERN const char sqlite3_version[]; I've tried: *version: make routine! [return: [string!]] *lib "sqlite3_version" but that doesn't seem to work. |
BrianH 17-Oct-2008 [752] | Routines only work for functions, not constants or variables. Is there a function that returns the value of that constant? |
Ashley 17-Oct-2008 [753] | const char *sqlite3_libversion(void); sqlite3_libversion() function returns a pointer to the sqlite3_version string constant. int sqlite3_libversion_number(void); sqlite3_libversion_number() interface returns an integer equal to SQLITE_VERSION_NUMBER. |
Robert 18-Oct-2008 [754x3] | What do you get back? This should work. |
Does the version number work? | |
call, I mean. | |
Ashley 18-Oct-2008 [757x2] | Got it, typo on my part. |
1.0.5 available at: http://www.dobeash.com/download.html Mac OS X now uses the v2 API and newer dylib path. SQLite/version now contains version number as a tuple! | |
BrianH 18-Oct-2008 [759] | What versions of SQLite does the new driver support? |
Ashley 18-Oct-2008 [760] | Versions 3.3.9 (first released 4-Jan-2007) onwards. Mac OS X used to ship with a really old version (3.0.8) dating from late 2004. |
Robert 19-Oct-2008 [761] | I'm currently using 3.6.3 and will update to 3.6.4 the newest release. |
sqlab 20-Oct-2008 [762x2] | Ashley, there is still a problem with Click/Button and over. The colour is irreversibly changing to the default in your demo |
sorry, wrong group. | |
Ashley 26-Nov-2008 [764] | 1.0.6 available at: http://www.dobeash.com/download.html Fixes finalize error as documented at: http://www.mtcnet.net/~henryvm/sqlite/ |
Robert 3-Dec-2008 [765x10] | Ashley, I just remembered that you can't call CONNECT/CREATE several times in one application. It gives the error "Database already connected" even if you use different file names. To open more than one database file you have to use the sql ATTACH command starting from the 2nd database file. |
I think makeing CONNECT handling this case implicit would make a lot of sense to make it simpler for users. So the programmer know, it's possible to alway call CONNECT/CREATE. What do you think? | |
BTW: I have this problem on Linux at the moment. The code runs with several calls on Windows. | |
Forget the last one. Doesn't work. | |
There is already a handler for this case but only if all databases are given upfront in a block. | |
And those files exist. | |
I now just commented the line that checks if a database is already connected. At least it now works but I'm not sure if this has some undesireable side-effects. | |
Ok, some more findings. I think the best way is to make a copy of the SQLite object for each database file. Than things are independent. The only thing to solve is to find an elegant way to select which SQLite object/connection to use without having to pre-fix all calls. | |
Any ideas for this? | |
Maybe something like a current database. | |
Ashley 3-Dec-2008 [775] | I'll look into it ... I like the idea of making this implicit. |
amacleod 3-Dec-2008 [776] | If I'm updating multiple fields is this the syntax? SQL reduce ["update books SET bk=?, chap=?, section=?, up_date=? WHERE id=?" book chapter section update id] I do not get an error but it does not seem to be updating all the fields. |
Robert 4-Dec-2008 [777] | Ashley, ok. Let's do it together, I can spend some time to discuss things and code some variants. |
Pekr 4-Dec-2008 [778] | Gyus, how to encrypt data in SQLite? I can't do it at app level (field storage level), as then SELECT would not work. Is the only solution to buy some SQLite variant, which encrypts at low level? |
Robert 4-Dec-2008 [779x2] | Yes. |
I did buy the extension. Works very well. | |
Pekr 4-Dec-2008 [781] | Any link? |
Sunanda 4-Dec-2008 [782] | Could you use (say) Truecrypt to host the data files on a encrypted partition? |
Pekr 4-Dec-2008 [783x2] | well, but at some point, you open-up that partition in order to be able to access it. The security is not there anymore. What I would like to have is direct SQLite low-level encryption, so that file might be visible to FS, but still encrypted. And your app provides password or something like that ... IIRC BrianH is using some such solution, I just don't remember its name. |
I am not hesitating to invest some money into it ... | |
Robert 4-Dec-2008 [785x2] | Look on the SQLite homepage under professional support. |
IIRC encryption costs $2000 | |
Pekr 4-Dec-2008 [787] | uff, so much? I expected something sub 500 ;-) |
Ashley 4-Dec-2008 [788] | Robert, I was thinking we can depreciate the /create refinement by making that implict as well ... and the change required to support additional CONNECTs after the first should be as simple as changing the line that reads: all [dbid sql-error "Already connected"] to something like: if all [dbid file? database] [ unless find file %/ [insert file what-dir] sql rejoin ["attach '" ... return ] which then raises the interesting question as to whether we should force database to be file! (so you'd have to attach multiple databases by issuing multiple CONNECTs ... it would certainly simply the CONNECT logic! ;) |
Robert 4-Dec-2008 [789x3] | I see one problem, if the to-be-opened database doesn't exists yet it needs to be created. This can only be done by a call to sqlite3_open and not via the ATTACH sql command. |
And than the returned DB handle has to be used for all actions against this database file. It's much like a file handler. | |
I see two options: 1. We enhance the driver to be able to handle more database handles at the same time. This needs a way to select a database handle as the current one. 2. We make the driver as a prototype object which carries everything for one database handle. Than we need a way how to state which instance to use. | |
amacleod 4-Dec-2008 [792] | Banging my head against a wall! This works: SQL reduce [{UPDATE notes SET note=?, up_date=? WHERE book=? AND chapter=? AND section=?} note_text now bk_tit/1 bk_tit/2 bk_tit/3] But this does not: SQL reduce ["Update fdbooks SET up_date=? WHERE ref_number=?" now ref] nor this: SQL reduce [{UPDATE notes SET note=?, up_date=? WHERE book=? AND chapter=? AND section=?} note_text now bk_tit/1 bk_tit/2 bk_tit/3] Any ideas? |
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