RE the first question, the largest positive 64-bit number is 18446744073709551615, or, 18,446,744,073,709,551,615. Your number is overloading that value. 12,345,678,901,234,567,890,123 vs 18,446,744,073,709,551,615
AFAIK, SQLite uses max of 64-bit integer math, not 128. On Thu, Jan 25, 2018 at 10:04 AM, Cezary H. Noweta <c...@poczta.onet.pl> wrote: > Hello, > > About year age I reported some strange behavior: > > 1. > > https://www.sqlite.org/lang_expr.html#castexpr: > > INTEGER: ``When casting a TEXT value to INTEGER, the longest possible > prefix of the value that can be interpreted as an integer number is > extracted from the TEXT value and the remainder ignored. [...] If there is > no prefix that can be interpreted as an integer number, the result of the > conversion is 0.'' > > sqlite> SELECT CAST('12345678901234567890123' AS INTEGER); > 4807115922877859019 > > What prefix of ``12345678901234567890123'' can be interpreted as > ``4807115922877859019''? > > 2. > > Why trailing spaces are allowed in FLOATs and not in INTEGERs? It would > not be a problem, if INTs were 32bit. Now, a value is lost: > > sqlite> CREATE TABLE a (a NUMERIC); > sqlite> INSERT INTO a VALUES ('9000000000000000001'),('9000000000000000001 > '); > sqlite> SELECT * FROM a; > 9000000000000000001 > 9000000000000000000 > > 2a. > > https://www.sqlite.org/lang_expr.html#castexpr: > > NUMERIC: ``Casting a TEXT or BLOB value into NUMERIC first does a forced > conversion into REAL but then further converts the result into INTEGER if > and only if the conversion from REAL to INTEGER is lossless and > reversible.'' > > Why a cast to universal AFFINITY (NUMERIC -- designed to represent both > INTEGERs as well as FLOATs) could be skewed into FLOAT direction loosing a > INTEGER's LSBits? INT is not 32bit wide. Hopefully above is not true: > > sqlite> SELECT CAST('9000000000000000001' AS NUMERIC); > 9000000000000000001 > > However due to pt 2.: > > sqlite> SELECT CAST('9000000000000000001 ' AS NUMERIC); > 9000000000000000000 > > The most concise patch (without, for example ``SELECT > CAST('9000000000000000001X' AS NUMERIC);'') contains only two lines: > ====== > --- sqlite-src-3220000/src/util.c 2018-01-23 01:57:26.000000000 +0100 > +++ sqlite-src-3220000/src/util.c 2018-01-25 14:22:18.428460300 +0100 > @@ -625,6 +625,7 @@ > zNum += (enc&1); > } > while( zNum<zEnd && sqlite3Isspace(*zNum) ) zNum+=incr; > + while( zNum<zEnd && sqlite3Isspace(zEnd[-incr]) ) zEnd-=incr; > if( zNum<zEnd ){ > if( *zNum=='-' ){ > neg = 1; > @@ -638,7 +639,7 @@ > for(i=0; &zNum[i]<zEnd && (c=zNum[i])>='0' && c<='9'; i+=incr){ > u = u*10 + c - '0'; > } > - if( u>LARGEST_INT64 ){ > + if( 19 < i || u>LARGEST_INT64 ){ > *pNum = neg ? SMALLEST_INT64 : LARGEST_INT64; > }else if( neg ){ > *pNum = -(i64)u; > ====== > > -- best regards > > Cezary H. Noweta > _______________________________________________ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
