Re: [sqlite] Am I understanding Blobs correctly?
Mike McGonagle wrote: > I have never used Blobs before, and in reading some of the literature, > I am just a bit confused. From what I am understanding, I get the > impression that a Blob is no more than the binary data from a disk > file, stored as a string of bytes in a field of the database. > > Basically, I am trying to write some multimedia stuff, and as such, > was thinking that I need to write some "filters" that access specific > types of data (a wav file, or a MIDI file, or etc.). If this is the > case, it almost sounds like it would be better to store the filename > for the data, and then let the system take care of reading the > particular format of the data. A blob in the general sense is a lump of data that is undifferentiated (eg into characters or digits or fields etc) as far as the DBMS is concerned, just a string of bits; it serves as a catch all when you want to store anything that isn't better served by some more specialized type like text or number. Others already mentioned some advantages of storing these in the database rather than the file system, for example making it easier to organize and you don't have to worry about addressing schemes etc like filenames, or rather you sort of do but a database gives you a lot more flexibility. One big thing that wasn't mentioned is that storing things in a database can often give you improved reliability. For example, if you have several changes to your data you want to make atomically, which includes your blob data, then simply marking all the changes as a transaction means the DBMS worries about making everything atomic, and you don't have the extra book keeping and hassle of doing that yourself, as you would if you have pieces in the file system. Now that's not to say that some file systems aren't transactional; some are, but most and typical ones are't, and many that say they are only make meta-data atomic not changes to the file content itself. -- Darren Duncan ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Am I understanding Blobs correctly?
On Jan 27, 2009, at 8:56 AM, Roger Binns wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA1 > > Mike McGonagle wrote: >> From what I am understanding, I get the >> impression that a Blob is no more than the binary data > > Binary large object. I came across this the other day: http://www.cvalde.net/misc/blob_true_history.htm ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Am I understanding Blobs correctly?
On 1/26/09, Mike McGonagle wrote: > Thanks, the datatypes are going to be varied, but I am sure the sizes > are the things I need to consider. I am not totally sure what you mean by "datatypes are going to be varied." The datatype for all the entries is going to be "blob." Perhaps you are referring to the type of "media" (wav file, midi file, mp3, image, etc.) that would be stored as a blob... well, that has nothing to do with the database. The database is just a store... you put data in it, and it faithfully gives you back the same data quickly and efficiently. What you do with it is up to you. Perhaps you can store the "type of media" (or call it whatever you want to) as an attribute of the blob, and use that attribute to figure out what to do with the data once it is pulled out of the table. > > > Mike > > > On Mon, Jan 26, 2009 at 8:27 PM, P Kishor wrote: > > If you have a lot of tiny images, especially if the images can be > > smaller than a page size in the db, then storing them in the db would > > be very efficient. If you have very large images then storing their > > path in the db, and keeping the images on the fs would be better. > > > > If you do keep your images on the file system, you will have to devise > > some method for naming and storing them... they will have to have a > > uniquely accessible path, and dumping them all in one folder will slow > > down access after a few hundred, perhaps a few thousand. In the db, on > > the other hand, you can just store the images in a separate table and > > assign them a primary key, then join them to your main attributes > > table. > > > > For most applications, it may not matter much, but when you are > > dealing with either very large size images, or very large number of > > images then one or the other system might be more suitable. > > > ___ > > sqlite-users mailing list > > sqlite-users@sqlite.org > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > > > > -- > Peace may sound simple—one beautiful word— but it requires everything > we have, every quality, every strength, every dream, every high ideal. > —Yehudi Menuhin (1916–1999), musician > -- Puneet Kishor http://www.punkish.org/ Nelson Institute for Environmental Studies http://www.nelson.wisc.edu/ Open Source Geospatial Foundation (OSGeo) http://www.osgeo.org/ ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Am I understanding Blobs correctly?
Thanks, the datatypes are going to be varied, but I am sure the sizes are the things I need to consider. Mike On Mon, Jan 26, 2009 at 8:27 PM, P Kishor wrote: > If you have a lot of tiny images, especially if the images can be > smaller than a page size in the db, then storing them in the db would > be very efficient. If you have very large images then storing their > path in the db, and keeping the images on the fs would be better. > > If you do keep your images on the file system, you will have to devise > some method for naming and storing them... they will have to have a > uniquely accessible path, and dumping them all in one folder will slow > down access after a few hundred, perhaps a few thousand. In the db, on > the other hand, you can just store the images in a separate table and > assign them a primary key, then join them to your main attributes > table. > > For most applications, it may not matter much, but when you are > dealing with either very large size images, or very large number of > images then one or the other system might be more suitable. > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > -- Peace may sound simple—one beautiful word— but it requires everything we have, every quality, every strength, every dream, every high ideal. —Yehudi Menuhin (1916–1999), musician ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] INNER JOIN, JOIN Confusin
"Cnichols" wrote in message news:21676221.p...@talk.nabble.com > What i am trying to do right now is select the questions that have > been asked for the current session (ie 7) > Stats - contains 46 rows with sessionid of 7 > Temp - holds 52 missed questions from the previous session (6) > > example - this works perfect; it returns 46 results > > SELECT COUNT() FROM Stats S > INNER JOIN Questions T ON S.QuestionId = T.Id > WHERE S.SessionId = 7 > > but if i do this > -- > SELECT COUNT() FROM Stats S > INNER JOIN Temp T ON S.QuestionId = T.Id > WHERE S.SessionId = 7 > > 51 results are returned? I do not understand why? Temp contains duplicate values in Id field. Or else, it's not true that Stats contains 46 records with SessionId=7 - confirm by running SELECT COUNT() FROM Stats S WHERE S.SessionId = 7; Igor Tandetnik ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Am I understanding Blobs correctly?
On 1/26/09, Mike McGonagle wrote: > Hello all, > > I have never used Blobs before, and in reading some of the literature, > I am just a bit confused. From what I am understanding, I get the > impression that a Blob is no more than the binary data from a disk > file, stored as a string of bytes in a field of the database. > > Basically, I am trying to write some multimedia stuff, and as such, > was thinking that I need to write some "filters" that access specific > types of data (a wav file, or a MIDI file, or etc.). If this is the > case, it almost sounds like it would be better to store the filename > for the data, and then let the system take care of reading the > particular format of the data. > If you have a lot of tiny images, especially if the images can be smaller than a page size in the db, then storing them in the db would be very efficient. If you have very large images then storing their path in the db, and keeping the images on the fs would be better. If you do keep your images on the file system, you will have to devise some method for naming and storing them... they will have to have a uniquely accessible path, and dumping them all in one folder will slow down access after a few hundred, perhaps a few thousand. In the db, on the other hand, you can just store the images in a separate table and assign them a primary key, then join them to your main attributes table. For most applications, it may not matter much, but when you are dealing with either very large size images, or very large number of images then one or the other system might be more suitable. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] INNER JOIN, JOIN Confusin
On 27/01/2009 12:00 PM, Cnichols wrote: > I have stumped myself with this sql goal. > > With this statement I am working with 3 tables > Stats - contains question asked history and if it was answered correcty > sessionid > questionid > correct > Questions - contains a list questions and mul choice answers and answer > id - pk > > . > etc. > Temp - schema is exactly like questions except contains missed questions > from a previous defined sessionid > > What i am trying to do right now is select the questions that have been > asked for the current session (ie 7) > Stats - contains 46 rows with sessionid of 7 > Temp - holds 52 missed questions from the previous session (6) > > example - this works perfect; it returns 46 results > > SELECT COUNT() FROM Stats S > INNER JOIN Questions T ON S.QuestionId = T.Id > WHERE S.SessionId = 7 > > but if i do this > -- > SELECT COUNT() FROM Stats S > INNER JOIN Temp T ON S.QuestionId = T.Id > WHERE S.SessionId = 7 You said "Temp - holds 52 missed questions from the previous session (6)" so shouldn't the WHERE clause be: WHERE S.SessionId = 6 ? If not, change your query to do SELECT S.*, T.* FROM etc etc also select the 52 from Temp and work out which one is missing -- maybe a value of Temp.Id is wrong (i.e. doesn't match up with a value of Stats.QuestionId) > > 51 results are returned? I do not understand why? > HTH, John ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Am I understanding Blobs correctly?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Mike McGonagle wrote: > From what I am understanding, I get the > impression that a Blob is no more than the binary data Binary large object. Large is by comparison to other typical data in a database. For example numbers are typically up to 10 digits long and text strings range from a few characters and probably average out at ten to twenty characters. Blobs are typically much larger than that. You also can't use text functions to act on them (eg regular expressions, LIKE). > from a disk file, The origin of blob data is irrelevant. > stored as a string of bytes in a field of the database. SQLite stores blobs as a sequence of bytes in the database file. > Basically, I am trying to write some multimedia stuff, and as such, > was thinking that I need to write some "filters" that access specific > types of data (a wav file, or a MIDI file, or etc.). If this is the > case, it almost sounds like it would be better to store the filename > for the data, and then let the system take care of reading the > particular format of the data. Although SQLite does handle blobs fairly well, common practise is to do exactly as you say - store the filename in the database. Any blob you store in the database has a practical size limit of 1GB and a theoretical maximum of 2GB. Storing the items in the database directly is beneficial if the database has to be moved amongst machines since the other files don't have to be dragged along as well. If you want to hide from your database code what is really going on underneath the hood then I'd recommend using a virtual table. Your virtual tables can automagically make it look like the blob data is stored in the database but behind the scenes have it in separate files or in the database. Profiling will then tell you which is most performant for your application. Roger -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkl+aeUACgkQmOOfHg372QSXtwCgqgd5ZXtHIC8mJZgPCY1/VK6H bVkAnR2EgwbsxZD5gC44Dp3Wxm12oki2 =Nl/Y -END PGP SIGNATURE- ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] Am I understanding Blobs correctly?
Hello all, I have never used Blobs before, and in reading some of the literature, I am just a bit confused. From what I am understanding, I get the impression that a Blob is no more than the binary data from a disk file, stored as a string of bytes in a field of the database. Basically, I am trying to write some multimedia stuff, and as such, was thinking that I need to write some "filters" that access specific types of data (a wav file, or a MIDI file, or etc.). If this is the case, it almost sounds like it would be better to store the filename for the data, and then let the system take care of reading the particular format of the data. Thanks, Mike -- Peace may sound simple—one beautiful word— but it requires everything we have, every quality, every strength, every dream, every high ideal. —Yehudi Menuhin (1916–1999), musician ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] INNER JOIN, JOIN Confusin
I have stumped myself with this sql goal. With this statement I am working with 3 tables Stats - contains question asked history and if it was answered correcty sessionid questionid correct Questions - contains a list questions and mul choice answers and answer id - pk . etc. Temp - schema is exactly like questions except contains missed questions from a previous defined sessionid What i am trying to do right now is select the questions that have been asked for the current session (ie 7) Stats - contains 46 rows with sessionid of 7 Temp - holds 52 missed questions from the previous session (6) example - this works perfect; it returns 46 results SELECT COUNT() FROM Stats S INNER JOIN Questions T ON S.QuestionId = T.Id WHERE S.SessionId = 7 but if i do this -- SELECT COUNT() FROM Stats S INNER JOIN Temp T ON S.QuestionId = T.Id WHERE S.SessionId = 7 51 results are returned? I do not understand why? My overall goal is to select a random unique question from Temp that has not been asked (so its not in stats for current session) and ORDER BY Random() LIMIT 1 Any help would be greatly appreciated! -- View this message in context: http://www.nabble.com/INNER-JOIN%2C-JOIN-Confusin-tp21676221p21676221.html Sent from the SQLite mailing list archive at Nabble.com. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Progress update while Prepare() is executing
On Mon, 26 Jan 2009 10:44:12 -0600, Nicolas Williams wrote in General Discussion of SQLite Database : >On Sun, Jan 25, 2009 at 01:32:57PM +0100, Kees Nuyt wrote: [...] >> To get a % progress indicator you need a more or less >> accurate estimate of what 100% is. You could gather some >> statistics and keep that in a table, and/or assume worst >> case every time. > >All excellent advice, but a small nit, tiny really: you can still have >some form of mildly useful progress indicator (a spinner, sand clock >mouse sprite turning, whatever) when you don't know what 100% is. All true, but Derek explicitly asked: >>> [...] the real point is that no one cares that the >>> first Querie takes so long as long as there some >>> progress indication (and I dont mean a endlessly >>> repeating progress bar) >I say >"mildly useful" because such indicators aren't useful when, >say, the app gets stuck in an infinite loop, or the operation >takes too long for the user to distinguish between "too long" >and "infinite loop" :) > >Still, it's useful enough as described by the docs: > >" >If the progress callback returns non-zero, the operation is interrupted. >This feature can be used to implement a "Cancel" button on a GUI >progress dialog box. >" Yes, that's useful. I hope Derek is still listening. -- ( Kees Nuyt ) c[_] ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Smaller issues with transactions in "undefined mode"
"D. Richard Hipp" schrieb im Newsbeitrag news:f6c1943c-f8ef-400a-800a-4afb2013f...@hwaci.com... > > This forgotten switch was causing a JournalMode = Off. > > > > Later on Transactions were used inside the Copy-over- > > process from FireBird. > http://www.sqlite.org/cvstrac/tktview?tn=3603 Ah, good - and with [6197] these problems should be gone. Will wait nonetheless for the next official release of your amalgamation - think the scenario is not all that common to require a "fast intermediate patch" of the engine-compile my wrapper uses. Thanks for the pointer - and as it seems you devs fix the bugs already before they are mentioned from "outside" - now that's really great "anticipatory support" I'd say... :-) Regards, Olaf ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] commit causes error - why?
Vance E. Neff wrote: > I'm having trouble on the "COMMIT TRANSACTION" Query. > > I seem, for some reason, to be violating a SQLite rule. > > This is from a language called RUN BASIC. > > Here is the test program, note that "" translates to a single " and > the print statements are just for this demo: > >#SQLiteDataBase EXECUTE( "SELECT MAX( ShoppingListIndex ) AS > MaxShoppingListIndex FROM ShoppingLists" ) > PRINT "Executed select max" >#CurrentQueryRow = #SQLiteDataBase #NEXTROW() > >#SQLiteDataBase EXECUTE( "COMMIT TRANSACTION" ) Before you can commit a transaction, you need to close all outstanding select statements. Figure out how to do the equivalent of sqlite3_reset or sqlite3_finalize in your programming language. Igor Tandetnik ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Smaller issues with transactions in "undefined mode"
On Jan 26, 2009, at 12:03 PM, Olaf Schmidt wrote: > > This forgotten switch was causing a JournalMode = Off. > > Later on Transactions were used inside the Copy-over- > process from FireBird. > > And that is, what I mean with "undefined mode" - > Journal-Mode=Off and nonetheless "transactions > on top" were somehow tolerated by the older > engines < 3.6.9 - but the newer engines are not > tolerating that anymore (and cause a crash). > http://www.sqlite.org/cvstrac/tktview?tn=3603 D. Richard Hipp d...@hwaci.com ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] Smaller issues with transactions in "undefined mode"
Hi Devs, This is not really a "bug-report", but I want to mention it nonetheless, since engine-crashes are probably not what should be left unhandled, regardless if the user tries to use the engine in an undefined-mode. Let me explain: Background: Platform Windows. StdCall-compile of the original "amalgamation". COM-Wrapper "on top". Crashes with each of the newer versions (3.6.9 and 3.6.10) - so, yes - the whole thing is probably related to the changes in the internal transaction- support of the engine. A user reported "full crashes" in a larger "copy- over-scenario" from another DB (FireBird). Switching back to the former engine 3.6.7 was working Ok. Finally the cause was a "left-over" switch, somewhere hidden in an Ini-File, which was introduced regarding "performance tuning" (together with switches for the different SyncModes and different PageSizes). This forgotten switch was causing a JournalMode = Off. Later on Transactions were used inside the Copy-over- process from FireBird. And that is, what I mean with "undefined mode" - Journal-Mode=Off and nonetheless "transactions on top" were somehow tolerated by the older engines < 3.6.9 - but the newer engines are not tolerating that anymore (and cause a crash). The transactions in question were used with the "older" standard-syntax (Begin Immediate, etc.) and not with the new introduced SavePointName- syntax. Regards, Olaf ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Progress update while Prepare() is executing
On Sun, Jan 25, 2009 at 01:32:57PM +0100, Kees Nuyt wrote: > If the replace statement is the same every time, you only > have to prepare it once. As drh said, to be able to help you > more, we need the schema and more detailed code. > > prepare() > begin() > while data_available{ > bind() > step() > reset() > [ clear_bindings() ] > } > commit() You might also prepare all statements at app startup time, which users might expect to be slow anyways, and maybe in a separate thread if there is other initialization work to do that can be done in parallel. If the schema changes, forcing you to re-compile your statements, and they really take that long to prepare, then have some sort of UI indication of this. Hopefully you can keep the frequency of schema changes down. Cheers, Nico -- ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Progress update while Prepare() is executing
On Sun, Jan 25, 2009 at 01:32:57PM +0100, Kees Nuyt wrote: > The progress indicator of both REPLACE and SELECT can be > driven by the while { step() } loops in your program. > A progress callback is not of much use here, except for the > first step(), because the first step() returns after any > intermediate tables have been built. > > To get a % progress indicator you need a more or less > accurate estimate of what 100% is. You could gather some > statistics and keep that in a table, and/or assume worst > case every time. All excellent advice, but a small nit, tiny really: you can still have some form of mildly useful progress indicator (a spinner, sand clock mouse sprite turning, whatever) when you don't know what 100% is. I say "mildly useful" because such indicators aren't useful when, say, the app gets stuck in an infinite loop, or the operation takes too long for the user to distinguish between "too long" and "infinite loop" :) Still, it's useful enough as described by the docs: " If the progress callback returns non-zero, the operation is interrupted. This feature can be used to implement a "Cancel" button on a GUI progress dialog box. " Nico -- ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] commit causes error - why?
I'm having trouble on the "COMMIT TRANSACTION" Query. I seem, for some reason, to be violating a SQLite rule. This is from a language called RUN BASIC. Here is the test program, note that "" translates to a single " and the print statements are just for this demo: [code] CLS PRINT "Start" SQLITECONNECT #SQLiteDataBase, "Shopper.dbs" #SQLiteDataBase EXECUTE( "SELECT MAX( ShoppingListIndex ) AS MaxShoppingListIndex FROM ShoppingLists" ) PRINT "Executed select max" #CurrentQueryRow = #SQLiteDataBase #NEXTROW() ShoppingListIndex$ = STR$( (#CurrentQueryRow MaxShoppingListIndex()) + 1 ) PRINT "Figured next index value" #SQLiteDataBase EXECUTE( "BEGIN TRANSACTION" ) PRINT "Began transaction" #SQLiteDataBase EXECUTE( "INSERT Into ShoppingLists (CustomerIndex, ShoppingListDate, ShoppingListTime, ShoppingListIndex, CombinedShoppingList ) Values (""1"", ""01/25/2009"", ""12:50:30"", ""1"", ""0"" )" ) PRINT "Inserted new data into ShoppingLists" #SQLiteDataBase EXECUTE( "COMMIT TRANSACTION" ) PRINT "committed transaction" #SQLiteDataBase DISCONNECT() PRINT "End" END [/code] And here is the displayed output: Start Executed select max Figured next index value Began transaction Inserted new data into ShoppingLists Runtime Error in program 'TestProblem': #SQLiteDataBase EXECUTE( "COMMIT TRANSACTION" ) SQL logic error or missing database This error was triggered by SQLite. If I remove the 3 lines (not counting the PRINT statements): [code] #SQLiteDataBase EXECUTE( "SELECT MAX( ShoppingListIndex ) AS MaxShoppingListIndex FROM ShoppingLists" ) PRINT "Executed select max" #CurrentQueryRow = #SQLiteDataBase #NEXTROW() ShoppingListIndex$ = STR$( (#CurrentQueryRow MaxShoppingListIndex()) + 1 ) PRINT "Figured next index value" [/code] The program runs successfully. Or, if I insert a disconnect and connect sequence just after those lines, the program runs OK. Why? Thanks for any help! Vance ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] codepages
"Sherief N. Farouk" schrieb im Newsbeitrag news:000301c97e09$2556f0f0$7004d2...@com... > > dear users > > I use sqlite for vb6, utf-8 database, > > when insert arabic data to database > > and search it with 'like' operator > > (within % syntax), return all records!!! > > Please help me... > > thanks I'm somehow missing the original message, so I'll reply here: Regarding VB6 - you could try out my wrapper (either the older dhSQLite or the newer version which comes in dhRichClient.dll) These VB6-based COM-Wrappers already contain appropriate Overrides for the Like-function, Upper(), Lower() and also the NoCase-Collation, where under the hood a fast UTF8->UCS2-BSTR- conversion is done - also included is an optimization for the overriden Like with regards to the usage of a predefined index for Like-queries of the form: SomeField Like 'abc%'. So normally that should work with no problems. Regards Olaf Schmidt ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] codepages
Sherief N. Farouk writes: > > > dear users > > I use sqlite for vb6, utf-8 database, > > when insert arabic data to database > > and search it with 'like' operator > > (within % syntax), return all records!!! > > Please help me... > > thanks > > John Smith > > ___ > > Arabic, in general, is one hell of a language to deal with. Can you provide > some sample data, like a db file and sample query? > > - Sherief > See http://www.sqlite.org/lang_expr.html#like and http://www.sqlite.org/lang_corefunc.html#like You might wish to implement your own Arabic-aware like(). MikeW ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] What is the advantage of using native c API over ODBC
goldy writes: > > Hi All, > > What are the basic advantage of using SQLite with C API over ODBC. Whereas the advantage of ODBC is having the same(?) interface to different database systems. Horses for courses ... MikeW ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] How many tables can a database hold?
J. R. Westmoreland writes: > > Can someone tell me how many tables a given database can hold. > > I'm looking at an initial design of an application that could have a table > of data for each city in a state. This could be possibly more than a > thousand tables. > > With that many tables how would the performance of the database be effected? > > Thanks, > > J. R. As others have observed, this is an unwise design, not least that any code written will have to 'edit' in the city table name by program rather than having it manipulable by SQL statements and 'bound' values. Like sets of items ("entity/relationship sets") should go into the same table with a column/field value to distinguish the instances. You can easily say "... WHERE City='Boston' ..." or whatever. Another way of putting this is that separate tables should not usually be used just to group sets of otherwise identically-structured data records. Search keywords: database schema design entity relationship Regards, MikeW ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] problem with view
On 1/26/09, MEVEL Marie (PDL/ELOG PDL) wrote: > Hello. I use SQlite and i create a database since 3 week. I'm never > have problem but yesterday, i consult my database and one table doesn't > want to show it. When i want to see data to this table, the message is : > "there are no items to show in this view". I search in the internet but > i don't find solution to my problem. Can you help me please ?! > > ps : i'm french, so , do you want use simple language to answer me > please. > Please provide the following information -- 1. The operating system and sqlite version you are using; 2. What program you use to look at your data. In other words, how do you "consult" your database. 3. Your database schema, that is, the table definitions; 4. How many records do you expect to see in the table that "shows" no records; 5. What SQL query do you use to see the records in that table; -- Puneet Kishor http://www.punkish.org/ Nelson Institute for Environmental Studies http://www.nelson.wisc.edu/ Open Source Geospatial Foundation (OSGeo) http://www.osgeo.org/ ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] JDBC and sqllite 1.1
Sorry, the right version is 2.1: the db is used by my MP3 player and I would like to create an application to manage the songs. I would like to write it using JAVA: the first problem is find out the right JDBC driver. Thanks, Garp Da: Kees Nuyt A: sqlite-users@sqlite.org Inviato: Venerdì 23 gennaio 2009, 18:58:32 Oggetto: Re: [sqlite] JDBC and sqllite 1..1 On Fri, 23 Jan 2009 00:26:00 -0800 (PST), Alessandro Corti wrote in General Discussion of SQLite Database : >The last version of the jdbc is unable to connect >to my old sqlite 1.1 db. >I'm looking for a jdbc driver for sqlite 1..1. Are you sure 1.1 applies to the SQLite version? The highest version in the SQLite v1 series I can find is Version 1.0.32, dated 2001-23-07. http://www.sqlite.org/cvstrac/timeline?d=180&e=2002-Jan-01&c=0&px=&s=9&dm=1&debug1=1&m=1&x=1 >Where can I find it? I would migrate everything to new versions. If that is too much of an effort, and you have to use the old database format, why not simply keep using the ancient jdbc version that is able to access it? >Best regards, >Garp -- ( Kees Nuyt ) c[_] ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Lock SQLite file by overwriting bytes and then un-lock?
Thanks; will do that. RBS -Original Message- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of MikeW Sent: 26 January 2009 12:02 To: sqlite-users@sqlite.org Subject: Re: [sqlite]Lock SQLite file by overwriting bytes and then un-lock? RB Smissaert writes: > > Thanks for the tip, but does that work on a Windows Mobile device? > > RBS Don't know - also look at http://www.freeotfe.org/ (Google: encrypted files windows mobile) Cheers, MikeW ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Lock SQLite file by overwriting bytes and then un-lock?
RB Smissaert writes: > > Thanks for the tip, but does that work on a Windows Mobile device? > > RBS Don't know - also look at http://www.freeotfe.org/ (Google: encrypted files windows mobile) Cheers, MikeW ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Lock SQLite file by overwriting bytes and then un-lock?
Thanks for the tip, but does that work on a Windows Mobile device? RBS -Original Message- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of MikeW Sent: 26 January 2009 11:40 To: sqlite-users@sqlite.org Subject: Re: [sqlite]Lock SQLite file by overwriting bytes and then un-lock? RB Smissaert writes: > > For some reason this mail went to the junk mail folder. > That sounds good and I would be happy to buy this, but I am not sure about: > > All you need to do is replace the DLL > I have number of dll's: > For the desktop: an ActiveX dll and a plain Windows dll. The ActiveX is used > by my VBA/VB6 app and that ActiveX uses the plain Windows dll. These files > are compiled by Olaf Schmidt. > On the WM6 device: A .net dll System.Data.SQLite.DLL and a little Basic4PPC > dll, SQLDevice.dll, which I think is also a .net dll. These files are > compiled by Erel, the author of Basic4PPC. > How would SEE fit in with all this? > > RBS Since you are running Windows, I would have the app and standard SQLite DB, and all ancillary data, stored on an properly encrypted drive. e.g. http://www.truecrypt.org/ You can't be too careful with sensitive data like this. Regards, MikeW ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Lock SQLite file by overwriting bytes and then un-lock?
RB Smissaert writes: > > For some reason this mail went to the junk mail folder. > That sounds good and I would be happy to buy this, but I am not sure about: > > All you need to do is replace the DLL > I have number of dll's: > For the desktop: an ActiveX dll and a plain Windows dll. The ActiveX is used > by my VBA/VB6 app and that ActiveX uses the plain Windows dll. These files > are compiled by Olaf Schmidt. > On the WM6 device: A .net dll System.Data.SQLite.DLL and a little Basic4PPC > dll, SQLDevice.dll, which I think is also a .net dll. These files are > compiled by Erel, the author of Basic4PPC. > How would SEE fit in with all this? > > RBS Since you are running Windows, I would have the app and standard SQLite DB, and all ancillary data, stored on an properly encrypted drive. e.g. http://www.truecrypt.org/ You can't be too careful with sensitive data like this. Regards, MikeW ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] problem with view
Hello. I use SQlite and i create a database since 3 week. I'm never have problem but yesterday, i consult my database and one table doesn't want to show it. When i want to see data to this table, the message is : "there are no items to show in this view". I search in the internet but i don't find solution to my problem. Can you help me please ?! ps : i'm french, so , do you want use simple language to answer me please. Thanks ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users