Thank you Thomas, that was most helpful. I have just found the ROWID information (http://sqlite.org/lang_createtable.html#rowid) - this is what I was looking for! You have to know something exists before you can look for it.... I take it this value will not change, even if the contents of its row change?
One more question though (there always is) - I see a ROWID is automatically assigned to each row in the table. How does one access this value? I know I can create my own INTEGER PRIMARY KEY column, which becomes an alias for the ROWID, but is there a way I can get the 'original' (I don't want to add a column at this stage)? If I call sqlite3_get_table(), it returns that ***result array (I'm using C++), but AFAIK that doesn't contain the ROWID. As Mañuel would say, ¿qué? Sholto Thomas Briggs-2 wrote: > > "It won't be too big..." famous last words. > > I think the rowid is probably safe for what you're trying to do, > despite the well-intentioned advice others have given you against it. > > Also, if you think the underlying data may change, then I'm not > sure what good reading the whole table will give you... if the > underlying data changes, row #28 the first time around may not be row > #28 the second time around. Even if you use an ORDER BY clause, which > you'll absolutely have to do if you go the read-whole-table route. > > What you might want to do is build a map between row number in your > grid and rowid in the database... that way you aren't relying on the > rowids being set a certain way, nor relying on the rowids being > returned to your app in a particular order. > > -T > > On Thu, Feb 19, 2009 at 9:09 PM, His Nerdship > <slgdoug...@optusnet.com.au> wrote: >> >> OK, thanks for the info. >> I will just do what I said before, namely read the whole table (it won't >> be >> too big) and extract the required row from the returned array. >> The reason I wanted a row ID was that all the fields in the display grid >> can >> be edited, so by the time I come to process it, any of them might have >> changed from the original in the database so I can't use them in a WHERE >> clause. >> At least I know now.... >> Thanks again >> >> >> P Kishor-3 wrote: >>> >>> On Thu, Feb 19, 2009 at 6:54 PM, His Nerdship >>> <slgdoug...@optusnet.com.au> wrote: >>>> >>>> Hi, >>>> I am converting a program from Paradox (stop laughing, please) to >>>> SQLite. >>>> Paradox has a useful feature where you can specify the actual index of >>>> a >>>> row >>>> in the table. This is handy when the table is displayed in a grid and >>>> you >>>> want the record corresponding to a row in that grid - you can just >>>> specify >>>> the index, say 28, of that grid row and it will get the record no 28 >>>> from >>>> the table. It spares the need for a SELECT statement, and is a lot >>>> more >>>> efficient. >>>> As a SQLite newbie, the only way I can see to do this is to read the >>>> whole >>>> table with sqlite3_get_table() and then get the required row from the >>>> returned array. This seems overkill when I just want a single record. >>> >>> There is the rowid, but I am not sure what you want to do... are you >>> expecting a database table to be a linear list of entries? Generally >>> one uses a spreadsheet for that kind of stuff. A SQL database doesn't >>> have an internal concept of order. You specify a criteria and the db >>> returns a SET of rows or records. You can constrain the SET by >>> specifying criteria (the WHERE clause), and you can impose an order on >>> the returned rows by specifying an ORDER clause. >>> >>> If you want just one specific row, just do a >>> >>> SELECT cols FROM table WHERE some_primary_key = ? >>> >>> If you don't want to specify and control your own primary key, you can >>> use the rowid which is something the db uses internally for its own >>> shenanigans. >>> >>> >>>> Is there a more compact way of doing this? >>>> Thanks in advance etc. >>>> Sholto >>> >>> >>> >>> -- >>> 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/ >>> Sent from: Madison Wisconsin United States. >>> _______________________________________________ >>> sqlite-users mailing list >>> sqlite-users@sqlite.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>> >>> >> >> -- >> View this message in context: >> http://www.nabble.com/Any-concept-of-row-number-in-SQLite--tp22112862p22113562.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 >> > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > -- View this message in context: http://www.nabble.com/Any-concept-of-row-number-in-SQLite--tp22112862p22114364.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
