Hi, Currently our customer uses PostgreSQL 9.6 and hits ECPG's bug during using numeric data type by SQLDA. I confirmed that this problem is occurred on master and 9.6 latest branch.
PROBLEM --------------------------------------- When the integer part of numeric data type is "0", cancellation of significant digits is occurred. For example, I expect "0.12345", but I got "0.12340". When I expect "0.01234", I got "0.01200" I attached the sample application code to reproduce this problem. CAUSE --------------------------------------- When copy the data of numeric data, the size is wrong. "src/interfaces/ecpg/ecpglib/sqlda.c" has problem. ecpg_set_native_sqlda(int lineno, struct sqlda_struct ** _sqlda, const PGresult *res, int row, enum COMPAT_MODE compat) { ... if (num->ndigits) { ecpg_sqlda_align_add_size(next_offset, sizeof(int), num->ndigits + 1, &offset, &next_offset); memcpy((char *) sqlda + offset, num->buf, num->ndigits + 1); ((numeric *) sqlda->sqlvar[i].sqldata)->buf = (NumericDigit *) sqlda + offset; ((numeric *) sqlda->sqlvar[i].sqldata)->digits = (NumericDigit *) sqlda + offset + (num->digits - num->buf); } ... When numeric data is "0.12345", num->buf has "0 0 1 2 3 4 5" and num->digits has "1 2 3 4 5". num->ndigits has the number of digits which is or later "1", it means 5. In this code, currently copy "num->ndigits + 1" as size of numeric data. As a result, (char *) sqlda + offset has "0 0 1 2 3 4", not "0 0 1 2 3 4 5". So, "num->digits - num->buf + num->ndigits" should be copied. FIX --------------------------------------- Above source code should be fixed and other similar bugs are fixed too. I attached patches for bug fix and regression test for master branch. I hope this bug fix will be backport to other versions. Regards, Daisuke Higuchi
001_ecpg_numeric_bugfix_v1.patch
Description: 001_ecpg_numeric_bugfix_v1.patch
numeric_sample_test.pgc
Description: numeric_sample_test.pgc
002_ecpg_numeric_test_v1.patch
Description: 002_ecpg_numeric_test_v1.patch