Hi Richard, Thank you for clarification. And yes, you are right with the guess, that the customer wants to preserve that much digits ;) br, Mathias
2011/8/2 Richard Hipp <d...@sqlite.org>: > On Tue, Aug 2, 2011 at 12:18 PM, Mathias Legerer > <mathias.lege...@gmail.com>wrote: > >> Hi, >> I noticed a strange behaviour, when i have a table with a text-field >> and i put a big float-number into it. >> When stored, it is increased by one. >> > > Floating-point numbers are approximations. Always. No exceptions. SQLite > promises to preserve 14 significant digits. You're getting 15.5 significant > digits. Count your blessings. > > (1) Unless you are doing number theory or cryptography, you don't need that > many significant digits. No real quantity can be measured with that much > accuracy. > > (2) If your boss or your customer insists that you preserve more digits (in > spite of the fact that in any real-world application, anything after about > the 5th or 6th digit is probably just noise), then use integers. > > FWIW, Linux preserves all 16 digits. I suppose the difference is how winXP > sets up the on-chip floating point hardware. > > >> >> create table TEST (ordnr int primary key, ktoid TEXT); >> insert into TEST (ordnr, ktoid) values(0, 991000004499464.0); >> SELECT ordnr, ktoid FROM TEST; >> 0|991000004499465.0 >> >> I believe, this is just because of some conversion-library. >> Documenation says: "If numerical data is inserted into a column with >> TEXT affinity it is converted into text form before being stored" >> >> I thought that this would work without any problems, but it seems >> there is some limit for floats/real as text if you look at this bigger >> number: >> insert into TEST (ordnr, ktoid) values(3, 99100000449946222.0); >> -> 3|9.91000004499462e+16 >> >> Is there some documentation about this limit? >> Is it system-dependend? >> I am working on WinXP 32Bit. >> >> Thank you for any information. >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > > > > -- > D. Richard Hipp > d...@sqlite.org > _______________________________________________ > 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